Solar Storms

Solar Storms in a Nutshell

[Source: Wikipedia]

Our Sun has a cycle of roughly 11 years. At the maximum/peak there are many more sunspots than at the minimum, and 50 times as many solar flares. The next maximum is due in late 2012 / early 2013.

Solar flares are sometimes accompanied by solar proton events and coronal mass ejections (see below). CMEs that are directed towards Earth can interact with our planet’s magnetic field to produce a geomagnetic storm. Not every solar storm will produce all three elements but the largest solar storms typically do.

The Components of a Solar Storm

This is the normal pattern of events

Solar Flares

Arrival Time: 8 minutes (speed of light)

Effect Duration: 1-2 hours

Harm: Electromagnetic radiation in the form of X-rays, extreme ultraviolet rays, gamma ray radiation and radio bursts. They can disrupt radar, satellite communications and radio.

Solar Proton Event

Arrival Time: 15 minutes to a few hours

Effect Duration: Days

Harm: Cosmic Rays which can cause satellite disorientation, spacecraft electronics damage, spacecraft solar panel degradation, extreme radiation hazard to astronauts, high altitude aircraft radiation, shortwave radio fades and disruption in polar regions, ozone layer depletion, cardiac arrest, dementia and cancer.

Coronal Mass Ejection

Arrival time: 2 or 4 days

Effect Duration: Days

Harm: CMEs consist of gas and charged plasma of energy particles A flood of charged particle and electrons in the ionosphere flow from west to east, inducing powerful electrical currents in the ground that surge through natural rock. CMEs can have the following affects: radar errors, radio anomalies, compass errors, electrical power blackouts, oil and gas pipeline corrosion, phone line & equipment damage, electrical shock hazard, electrical fires, heart attacks and strokes. CMEs are also the cause of auroras.

Source: Solar Storm Threat Analysis

Solar Storms of the last 150 years

Here are a few examples of modern harm from solar storms, followed by the most famous storm to date. More details can be found at SolarStorms.org

1921 – Telegraph system down west of the Mississippi, Central New England railroad station destroyed by fire
1942 – Allied radar disrupted during WW2
1972 – Transformer explodes in British Columbia
1984 – Air Force One loses communications en route to China
1989 – Quebec power outage
1989 – Toronto stock exchange computers crash
1994 – Canada’s Anik E1 satellite goes off air for 7 hours, affecting news and telephone services. Then Anik E2 goes off air for good
2011 – On Valentine’s Day some radio communications were lost, causing some polar flights to be re-routed

September 1, 1859 – The Carrington Event

Just before noon… English astronomer Richard C. Carrington was sketching a curious group of sunspots—curious on account of the dark areas’ enormous size. At 11:18 a.m. he witnessed an intense white light flash from two locations within the sunspot group. He called out in vain to anyone in the observatory to come see the brief five-minute spectacle, but solitary astronomers seldom have an audience to share their excitement. Seventeen hours later in the Americas a second wave of auroras turned night to day as far south as Panama. People could read the newspaper by their crimson and green light. Gold miners in the Rocky Mountains woke up and ate breakfast at 1 a.m., thinking the sun had risen on a cloudy day. Telegraph systems became unusable across Europe and North America.

from Scientific American, Aug 2008

In New York thousands of people lined the streets to view the auroral display, which was seen across North America:

From August 28 through September 4, auroral displays of extraordinary brilliance were observed throughout North and South America, Europe, Asia, and Australia, and were seen as far south as Hawaii, the Caribbean, and Central America in the Northern Hemisphere and in the Southern Hemisphere as far north as Santiago, Chile.

from Severe Space Weather Events

Remarkably, in some U.S. telegraph offices, operators disconnected the batteries and sent telegraphs using only the current induced by the aurora. But then life went on as usual and the Carrington Event was soon forgotten about. Even for scientists it was a curiosity, about as important as studying the seventh wave at the seashore… and it is only recently that this curiosity has been considered a serious threat to our lives.

The Sun Can Harm Our Infrastructure

Since 1859 we have seen the arrival of electronics, and with time our reliance on electronics has grown exponentially. A massive solar storm can harm our electrical grids, without which electronic products cannot operate (unless they run on batteries). Apart from some relatively minor events, the Sun has not yet attacked our grids, but that could just be good luck.

In a primary sense, a repeat of the Carrington Event would most likely cause the following damage:

Power Grids – in March 1989 an X15 flare caused the entire Hydro Quebec system to blackout, with 6 million customers going without electricity for between 9 hours and several days. During the last solar maximum of 2000/2001, NASA estimates that the wholesale cost of electricity in the USA rose by $500 million to cover the costs of solar storm damage.

Railway Tracks – the tracks are long metal conductors. Currents from a CME can damage signaling systems and ignite fires in railroad control stations.

Oil and Gas Pipelines – can suffer from corrosion and potentially failure.

Telephone Land Lines and Undersea Cables – like railway tracks and pipelines, phone lines and cables are also conductors. The induced current (from a CME) can damage transmission lines and any attached equipment tied to those lines. It can also cause equipment fires and people could receive severe electrical shocks.

Satellites – as an example, Japan’s Advanced Satellite for Cosmology and Astrophysics stopped functioning due to a solar storm in July 2000, and due to power losses it crashed to Earth eight months later. A bigger storm will likely knock out more satellites, including those that provide communications and GPS.

Radio and GPS – an x17 flare in Oct 2003 disrupted GPS functionality. According to the US Navy’s report, “the FAA’s Wide Area Augmentation System (WAAS), which uses GPS for aircraft navigation, was seriously impacted during the severe storms on October 29 and 30, and resulted in commercial aircraft being unable to use the WAAS for precision approaches.”

But the flow on effect would be substantial. Homeland Security created this graphic that is really just a brief overview of how inter-connected these things are:

Here are just some of things we’d need to live without:

Infrastructure – banks won’t be able to operate, nor will ATMs – they also use GPS for timestamping transactions. Traffic lights won’t work, causing traffic jams initially. Police and emergency services will struggle to communicate. Empty store shelves will not be refilled. Almost everyone will be unable to work their regular job.

Water – some cities have gravity-fed water available, but in most places we rely on electrical pumps to get water to our homes. Electricity is also needed at water purification plants. Apart from drinking water, consider that we use it to wash, to flush toilets, and to move sewage away from our homes. Without electricity many sewage plants will not operate normally.

Heating and Cooling – the loss of these could kill people during the winter and summer months.

Energy and Fuel – pipelines can fail, and the normal way to access stored fuel is with an electric pump. While manual pumping might get gasoline out at a gas station, the authorities or thugs will likely be in control.

And then there’s a special danger:

Nuclear Power Plants – without electricity there’s only diesel generators to keep the plant cool and avoid meltdown. It would not be surprising if the amount of diesel on hand is low, and the ability to obtain more or even ask for more could be low in a dark USA.

Put all the above together and you invoke the butterfly effect… one example is that crime will increase, due to looting. To keep the peace, looters would need to be arrested and jailed. But to operate jails with no electricity becomes problematic – no video surveillance, difficulties in providing food and water and so on – which means a lot more police need to be deputized, removing able-bodied men from other useful tasks. A police chief might decide that looting is a hanging offence…

Why Are Power Grids Vulnerable?

Scientific American explains it well:

Large transformers are electrically grounded to Earth and thus susceptible to damage caused by geomagnetically induced directcurrent (DC). The DC flows up the transformer ground wires and can lead to temperature spikes of 200 degrees Celsius or higher in the transformer windings, causing coolant to vaporize and literally frying the transformer. Even if transformers avoid this fate, the induced current can cause their magnetic cores to saturate during one half of the alternating-current power cycle, distorting the 50- or 60-hertz waveforms. Some of the power is diverted to frequencies that electrical equipment cannot filter out. Instead of humming at a pure pitch, transformers would begin to chatter and screech. Because a magnetic storm affects transformers all over the country, the condition can rapidly escalate to a network-wide collapse of voltage regulation. Grids operate so close to the margin of failure that it would not take much to push them over.

According to studies by John G. Kappenman of Metatech Corporation, the magnetic storm of May 15, 1921, would have caused a blackout affecting half of North America had it happened today. A much larger storm, like that of 1859, could bring down the entire grid. Other industrial countries are also vulnerable, but North America faces greater danger because ofits proximity to the north magnetic pole. Because of the physical damage to transformers, full recovery and replacement of damaged components might take weeks or even months.Kappenman testified to Congress in 2003 that “the ability to provide meaningful emergency aid and response to an impacted population that may be in excess of 100 million people will be a difficult challenge.”

The U.S. Congress has voted against providing funding that would harden the power grid and eliminate the possibility of a massive failure. It could be the worst decision they ever made.

Other power grids that are reasonably close to the poles, such as Europe, Russia, Australia, Argentina and South Africa are also at risk.

What Are The Odds?

Scientists guesstimate that a solar storm with the magnitude of the Carrington Event will only happen once every 500 years (based on nitrates found in ice cores representing the last 450 years). Storms with half its intensity should hit every 50 years or so. The last one occurred on November 13, 1960, and led to global geomagnetic disturbances and radio outages. The next is due now, at a time when satellites are substantially more important, and power grids are more vulnerable. Larger storms than the Carrington Event will also happen, although we don’t know how frequently. One model has shown that a storm 1000 times as strong is possible.

Heart Attacks and Strokes

Amazingly, studies have shown that during solar storms the frequency of hospital admissions for heart attacks and strokes is roughly double that of quiet solar periods. Magnetic pulses are thought to be the cause. Geomagnetic storms have also been linked to depression, enhanced anxiety, sleep disturbances, altered moods and psychiatric admissions (up 36%). Presumably there would be far greater increases during a storm like the Carrington Event.

Are We Prepared?

NOAA’s Space Weather Prediction Center provides daily space weather reports (their data appears at SpaceWeather.com) to businesses and government agencies. Its annual budget is a mere $6 million. It does provide advance warnings so that businesses can take precautionary measures, but there is a great deal of variability between their predictions and the actual damage that can occur. And with a Carrington-type event, the warning provides a mere 10-minute window in which to act.

When warning us about incoming geomagnetic storms, the NOAA’s only source of data is the Advanced Composition Explorer (ACE) satellite. It was launched in 1997, and according the the U.S. National Academy of Sciences in 2009, it is “well beyond its planned operational life”. I take this to mean it could fail any time, and there is no backup satellite! And all current safety measures become redundant – we won’t be able to remove vulnerable equipment from the grid before it is too late. “ACE is a single point of failure and it’s old,” said William Murtagh, program coordinator for NOAA’s Space Weather Prediction Center. “Every time I have a space weather storm I cringe a little bit that our very own space weather satellite doesn’t succumb to the storms I’m relying on it to help forecast.”

Power grids are prepared to some degree. The Hydro Quebec blackout of 1989 was due to circuit breakers shutting down the system before the flare could fry transformers. It is not known how dependable such safety systems are, for they have not been sufficiently put to the test. And of course human error is easily possible. The decision of when and how to shut down an electrical system might come down to one or two individuals. They might delay the shut-down too long, or they might think their jobs were at risk if they mistakenly switched off power to entire cities. The devastating Queensland floods of 2011 were the result of a similar type of human error – and they had days to make their decisions, not ten minutes.

Several million Preppers are prepared for this and various other catastrophes. That leaves hundreds of millions of Americans who are not prepared, as well as governments and infrastructures that have not made provisions for long-term losses of electricity.

Official Vulnerability Estimate

The following quote is from Severe Space Weather Events, a report commissioned by the National Research Council.

Severe space weather has the potential to pose serious threats to the future North American electric power grid. Recently, Metatech Corporation carried out a study under the auspices of the Electromagnetic Pulse Commission and also for the Federal Emergency Management Agency (FEMA) to examine the potential impacts of severe geomagnetic storm events on the U.S. electric power grid. These assessments indicate that severe geomagnetic storms pose a risk for long-term outages to major portions of the North American grid. John Kappenman remarked that the analysis shows “not only the potential for large-scale blackouts but, more troubling, . . . the potential for permanent damage that could lead to extraordinarily long restoration times.” While a severe storm is a low-frequency-of-occurrence event, it has the potential for long-duration catastrophic impacts to the power grid and its users. Impacts would be felt on interdependent infrastructures, with, for example, potable water distribution affected within several hours; perishable foods and medications lost in about 12-24 hours; and immediate or eventual loss of heating/air conditioning, sewage disposal, phone service, transportation, fuel resupply, and so on. Kappenman stated that the effects on these interdependent infrastructures could persist for multiple years, with a potential for significant societal impacts and with economic costs that could be measurable in the several-trillion dollars-per-year range.

…The least understood aspect of this threat is the permanent damage to power grid assets and how that will impede the restoration process. Transformer damage is the most likely outcome, although other key assets on the grid are also at risk. In particular, transformers experience excessive levels of internal heating brought on by stray flux when GICs cause a transformer’s magnetic core to saturate and to spill flux outside the normal core steel magnetic circuit. Kappenman stated that previous well-documented cases have involved heating failures that caused melting and burn-through of large-amperage copper windings and leads in these transformers. These multi-ton apparatus generally cannot be repaired in the field, and if damaged in this manner, they need to be replaced with new units, which have manufacture lead times of 12 months or more.

…In summary, present U.S. grid operational procedures are based largely on limited experience, generally do not reduce GIC flows, and are unlikely to be adequate for historically large disturbance events. Historically large storms have a potential to cause power grid blackouts and transformer damage of unprecedented proportions, long-term blackouts, and lengthy restoration times, and chronic shortages for multiple years are possible. As Kappenman summed up, “An event that could incapacitate the network for a long time could be one of the largest natural disasters that we could face.”

Finally, I can recommend this Feb 2012 article from the IEEE, which concludes ” If we do nothing—if we stand by and wait for politicians to appreciate the risks and act on them—we may witness one of the worst catastrophes of all time”

http://spectrum.ieee.org/energy/the-smarter-grid/a-perfect-storm-of-planetary-proportions/0

Asteroids and Comets

ASTEROIDS and COMETS

[The] story of how Phaëton, child of the sun, harnessed his father’s chariot, but was unable to guide it along his father’s course and so burnt up things on the earth and was himself destroyed by a thunderbolt, is a mythical version of the truth that there is at long intervals a variation in the course of the heavenly bodies and a consequent widespread destruction by fire of things on earth.
Plato
Timaeus

How Big Is The Risk?

Here is a rundown of the different sizes, their probabilities, the chances of us seeing them coming, and the theoretical approximates of the damage they could inflict. Because we know so little about the makeup of comets, I’ve lumped them in with asteroids for convenience.

1 kilometer diameter or larger
The aim of NASA and their various branches and allies is to discover at least 99% of these monsters.
http://neo.jpl.nasa.gov/faq/
A 10km asteroid strike would create waves in the Earth’s crust higher than houses, and a blast of 500ºC air travelling at 2500 kph. Any creature within 12 million sq km would be wiped out.(1) That’s roughly the size of the USA, Europe or Australia

500 metre
According to Duncan Steel (2), we are unlikely to discover more than half of the asteroids and comets in our solar system with a 500 meter diameter. Just one of these would create a crater 10km wide, and destroy all life within 1,000sq km.(3)

100 metre
These are so small, in terms of our ability to discover them, that only a few percent are likely to be spotted, says Steel. If a 100m asteroid struck Earth at 19km/sec the resulting crater would be 2km across, and it would destroy all life within 200sq km. These hit Earth with an average frequency of one every 22,000 years.(4) Or according to Gerrit L. Verschuur, as often as every 1,000 years (5).

50 metre – Tunguska size
Objects with a diameter of 50-60 meters pass closer to Earth than the Moon about once per week.(6) Aside from the famous Tunguska incident, and serving as a reminder that Tunguska was not a “one-off”, a smaller asteroid exploded mid-air over eastern Siberia in 1947, leaving “122 craters up to 26m wide and 5m deep.”(7) It weighed about 70 tonnes.

They Strike Earth All The Time!

Meteors do make it to Earth – here are some examples that serve as a reminder:

1 metre – Barwell, UK – 1965
Roughly half of Coventry, a city of 300,000 that it passed over, say they heard it. Some of the high frequencies given off meant horses heard it before it became visible. Those that could see it through the evening clouds estimated the tail to be 20 degrees long. It broke up into many pieces, and although some struck buildings, nobody was hurt.

Astrophysicists from the Herzberg Institute in Ottawa, Canada, have estimated that an average of 16 buildings are damaged by meteorites each year, with a human being hit every nine years, sometimes fatally.(8)

Recorded deaths by meteorites and asteroids:

588 AD, 10 people, China
1490, supposedly 10,000 people, China
1511, Franciscan monk, Cremona, Italy
1650, Another monk (!), Milan, Italy
1647-54, 2 sailors at sea
1790, A farmer and cattle, France
1825 , A man, India
1827, A man, India
1874, Child, China
1879, Man in bed, Indiana, USA
1879, Farmer, France
1897, Horse, West Virginia, USA
1907, Entire family, China
1908, 2 people reported, Tunguska
1911, Dog, Egypt
1929, 1 member of a bridal party, Zvezvan, Yugoslavia

Buildings are stuck, and people nearly hit, most years. A recent example (June 2009) involved a German schoolboy, Gerrit Blank, who was left with a scar on his hand when he was grazed by a meteorite that left a 30cm-wide crater in the pavement.

In 1931, three asteroid fragments struck a Brazilian jungle and 1,300 square kilometers of rainforest were destroyed by wall of fire. (9)

On February 1, 1994, near the Marshall Islands in the western Pacific, a handful of fishermen witnessed a hundred-kiloton explosion (that’s 10x Hiroshima) that momentarily flashed brighter than the sun. This asteroid has been estimated to be just 6-17 metres across, but plenty sufficient to decimate a city – so it was extremely fortunate (for humans) that it exploded above the ocean. According to Duncan Steel:

“It is therefore not surprising that the 10-meter-or-so asteroid that blew up over a largely vacant area of the western Pacific on February 1, 1994, producing an explosion equivalent to at least ten times that of the Hiroshima bomb (and possibly rather more), was not seen prior to impact. Surveillance satellites registered it as the brightest such explosion that they have picked up so far. Despite the efforts of numerous scientists in this area of study to make the military aware that such detonations do occur naturally, it appears that the U.S. President was awakened because the Pentagon thought that this incident might be a hostile nuclear explosion.” (10)

Relatively recent, large impacts

Merewether crater, west of Ungava Bay in Canada, is 200m in diameter and was formed less than 10,000 years ago. More recent is the Henbury crater cluster near Alice Springs, Australia. The twelve craters have been dated at between 2,000 and 6,000 years ago. The largest is 180m across and 15m deep. According to Aboriginal legend, the site is known as “sun walk fire devil rock”, suggesting that the event had witnesses.

Recent Near Misses

In 1937 an asteroid called Hermes, with a diameter of one kilometer, became the closest recorded passage to Earth. When it crossed our orbit it was 780,000kms away, twice the distance of the moon. In terms of time, it missed us by a mere 5 hours. It was reported 2 months later, with newspapers claiming we almost witnessed the destruction of our planet. (11)

1989 – a 300m asteroid (known as 4581 Asclepius or 1989 FC) missed us by 690,000kms and 7 hours. It was not spotted until after it had flown by. It is due to return in 2012, but is not expected to come as close.
1991 – a 100m asteroid (1991 BA) passed within 170,000kms.
1996 – a 300–500 m asteroid, (1996 JA1_, passed within 450,000 km of Earth

In the near future, the number one concern is a 320 m asteroid known as 99942 Apophis. Although when first discovered it was considered to have a 1 in 17 chance of hitting Earth, it is now understood to only come as close as 25,600 kilometres – close enough to knock out a communications satellite!

What Are The Odds?

Given recent examples, it is easy to believe that incidences of humans being killed by such impacts are rare. However, when you consider the catastrophic impacts that happen less often ( but when they do, can kill millions), the odds become a little bit more sobering. Austen Atkinson says the odds of being killed by a comet or asteroid is 1 in 24,000. (12) And then he points out that the odds of contracting mad-cow disease is 1 in 15 million, yet that scared most of the world enough to ban the importation of British beef.

1 in 24,000 is roughly the same odds for dying as a result of a plane crash. I’m not alone in worrying about this every time I board a plane…

The problem we have is easily understood – governments generally react after the fact, not before. It is only after some of us have suffered somehow that the government decides to do something about it – they are not in the business of scaring us with predictions of what might happen, unless it suits them (think pre-emptive military strikes).

The folk running the city of New Orleans were very aware of the risk of flooding they faced from hurricanes, and they chose to gamble that it wouldn’t happen on their watch, a gamble that they lost with Katrina. Appropriate spending, relative to the risk they faced, would have saved New Orleans. If it is an “Act of God”, our governments seem to universally elect to be underprepared for it. Especially when, in the case of New Orleans, to be prepared would have taken a commitment of $1billion and 20 years.

At present, NASA’s “Spaceguard Survey”, which aims to spot Near-Earth Objects greater than 1 kilometer in diameter, has a budget of $4.1 million per year from 2006 through to 2012. This is a pitiful effort, relative to the risk, and explains why most new comets are discovered by amateurs.

Effect of a Comet/Asteroid Striking Earth

The easiest to predict is the most likely – the collision occurring in the ocean. First of all, here’s some data regarding recent tsunamis caused by earthquakes and volcanoes…

1960: An earthquake in Chile with a magnitude of 9.5 (the largest magnitude ever recorded) caused the death of 6000 people worldwide. 61 of the victims were in Hawaii, as the result of a tsunami that arrived 14 hours later – when it struck it was 10-15 meters in height . The same tsunami killed 142 people in Japan, when it arrived 22 hours after the earthquake. By then its height had reduced to between 1 and 5 meters. The deep-water wave (the height of the tsunami before it reaches land) was only 20 cms.

2004: The Indian Ocean tsunami was caused by the second largest earthquake ever measured (9.1-9.3), and was much more devastating. It killed more than 225,000 people in eleven countries with waves as high as 30 meters. However, before reaching land it was mere 60 cms in height.

We don’t know when an asteroid or meteor will strike Earth next, but we know that in the past there have been many – they leave a crater. The type of tsunami they can create has not been recorded by humans (as far as we know), so all we have are best guesses coming from experts.

The threat of tsunamis caused by asteroid impacts has only recently been recognized, due to the work of Jack Hills and Patrick Goda of the Los Alamos National Laboratory in New Mexico. They have performed calculations showing that the hypothetical 500-meter asteroid mentioned earlier would produce a deep water wave 50 to 100 meters in amplitude, even at a range of 1,000 kilometers from ground zero. Since the tsunami height could be amplified by a factor of 20 or more in the run up as continental shelves are encountered, we are referring here to a tsunami several kilometers in height. Even if the impact were between New Zealand and Tahiti, the tsunami breaking on Japan would be perhaps 200 to 300 meters high, and heaven help New Zealand and Tahiti themselves!… (13)

In case you are wondering how far inland you would need to be to survive, formulas have been determined. A 200-300 meter tsunami hitting a populated coastline (buildings will slow it hinder its advance) will travel 50-100 kilometers inland, or even further if the terrain is flat. (14)

If you are thinking to yourself “fair enough, but I can’t imagine a tsunami that high ever occurring”, consider this; coral has been found in Lanai, Hawaii, 326 meters above sea level, quite possibly due to a tsunami passing through.

There have been several studies made regarding the Tunguska event. Two figure it was an asteroid, with a diameter of 60, or 90-190 meters. Another study decided it was a comet with a diameter of 1200 meters. (15) According to Duncan Steel, generally speaking, anything that can make it through the atmosphere without disintegrating, and affect more than just the spot where it crashes, would need to be 50 meters wide (for an asteroid) and 100 meters wide (for a comet). To put it another way, if it hits the ocean we either won’t notice, or there will be a substantial tsunami, and nothing in between. (16)

A 100-meter object will typically strike Earth once every 1,000 years, and if it struck land would lay waste to an area of about 10,000 square kilometers – roughly the same size as Connecticut. The deaths just from the impact would depend on the population density, but would be much less than if it struck the ocean. Shin Yabushita has calculated that the odds of most of the Pacific Rim cities being wiped out by an asteroid/comet driven tsunami, in the next century, is 1%. A sobering figure. (17)

In terms of survival, land and sea impacts are quite different. A sea impact will create a tsunami, and depending on the location, could wipe out many major cities. Once the waves subside, Earth is pretty much back to normal, but we will be missing the people and the infrastructure that were destroyed. While this would be tragic for the global economy, people living outside the path of the tsunami will still have their crops and climate, and life will go on.

A terrestrial impact might cause less immediate damage, but create long-term hardships.

Overall, Gilmour and his colleagues have identified a dozen “environmental stresses” caused by the K-T impact. The strong winds and tsunamis lasted for a matter of hours; fires lasted for months, as did the darkness and cold partly caused by the fires; the greenhouse effect began to take grip as the darkness cleared, boosted early on by the presence of water vapour in the air, and maintained by the long-term presence of carbon dioxide; poisons and mutagens remained active for years, as did the effects of acid rain; the ozone layer must have been severely disrupted by the disturbance to the atmosphere, and then there was the volcanic activity triggered by the impact. (18)

As a recent example, the Gribbins mention a “relatively modest” forest fire in California, 1987, which reduced valley temperatures by 15 degrees Celsius for an entire week.
With the ozone layer depleted by nitric oxides, crops would be burnt, and humans venturing outside unprotected would risk cancer. Few crops would survive acid rain, fires, extended periods of darkness and ozone depletion. Humans and animals would starve, and we would also miss the ability of plant life to remove carbon dioxide from our atmosphere. The amount of time it would take for Gaia to return to a steady state environment is not known.

The great K/T boundary extinction of 65 million years ago is a good example of how bad it can get, and how extinctions occur. A 15 kilometer wide asteroid crashed into North America. Debris from the impact was ejected into the atmosphere, and then fell as billions of tiny bullets. A fireball engulfed the continent, soot adding to the dust in the atmosphere. Global temperatures dropped by as much as 10 degrees Celsius. Plants died –they could not survive the triple-whammy of fire, acid rain and lack of sunlight. Large animals starved. Some smaller animals, those that didn’t mind feeding on dead tissue and rotting vegetation, managed to survive, as a species. Phytoplankton, dependant on sunlight, died. Because it was the fundamental basis of the oceanic food chain, the oceans became more about death than life. It is estimated that 75 percent of all Earth’s species became extinct following that singular asteroid impact.

Would we be warned? And how?

In March 1996, a declaration by the Council of Europe, discussing the dangers of Near-Earth Objects, and name-checking Tunguska and Shoemaker-Levy, said that the “possible consequences are so vast that every reasonable effort should be encouraged to minimise them.” (19)

A single impact by a rock the size of the Millennium Dome could devastate the surface of the globe with an explosive release of energy five times more powerful than the entire world’s nuclear arsenal. On 19 May 1996, just such an object came within 280,000 miles of Earth: six hours from collision.

Humankind could have been eradicated.

The asteroid (named JA1) sailed into our system – the largest object to approach Earth, other than the moon, since records began in 1833 – and was only four days away before two astronomers (Tim Spahr and Carl Hergenrother) in Tuscon, Arizona, detected it and alerted the US National Aeronautics and Space Administration (NASA). No one was prepared. Nothing could be done to prevent its approach. Yet no one was told: no public warning was given. The world’s powers watched the asteroid approach, impotent and unable to prevent the end of human civilisation. At the last moment, when it was only 400,000 miles, or seven hours, away from impact, its trajectory carried it away from our world. (20)

A few months later physicist Edward Teller wrote to the British Prime Minister, warning him of the serious threat posed by asteroids and comets – Teller, as a key player in the development of the hydrogen bomb, knew all about how fragile human existence is. (21)

The same year the US Department of Defense created a report that said:

Due to a lack of awareness and emphasis, the world is not socially, economically or politically prepared to deal with the vulnerability of …ECO (Earth Crossing Object) impacts and their potential consequences.

…These authors contend that the stakes are simply too high not to pursue direct and viable solutions to the ECO problem. Indeed, the survival of humanity is at stake. (22)

One of the brightest comets ever seen was Halle-Bopp. With a nucleus estimated at 40kms it is certainly large enough to wipe out all of humankind. It is rather discomforting to learn that we only noticed it in 1995, and if it happened to have been aimed straight at us, would have struck in 1997. Two years would not be enough time to plan/build/launch a defense.

While asteroids mostly follow the same plane of orbit as the planets, quite a narrow band of sky that is under regular observation – comets can come from anywhere, they can sneak up on us. Consequently comets tend to be discovered by amateur astronomers, while NASA lacks the funds (and perhaps willingness) to carry out full-sky observations.

It is not for me to speculate on our future ability to change the path of an asteroid or comet, should one have our planet in its sights. But based on what is currently known, it seems unlikely that we will be prepared to take on such an object if it was destined to crash into us in 2012. However, you never know what NASA might have been putting together in secret.

Therefore my presumption is this, we cannot thwart a comet or asteroid, and if one strikes us in 2012 there will be significant loss of life, depending on the size and location of impact. The bigger it is, the more likely we are to see it coming, yet the greater the odds of it wiping out all of humanity.

1. Peter Grego, Collision Earth (Blandford, 1998), 92.

2. Duncan Steel, Rogue Asteroids and Doomsday Comets (John Wiley & Sons, Inc., 1995), 222.

3. Grego, Collision Earth, 106.

4. Ibid.

5. Vershuur, Gerrit L., Impact!: the threat of comets and asteroids, 166

6. Steel, Rogue Asteroids and Doomsday Comets, 236.

7. Grego, Collision Earth, 79.

8. Ibid., 71.

9. Austen Atkinson, Impact Earth (Virgin, 1999), 81.

10. Steel, Rogue Asteroids and Doomsday Comets, 203-204.

11. Grego, Collision Earth, 101.

12. Atkinson, Impact Earth, 8.

13. Steel, Rogue Asteroids and Doomsday Comets, 40.

14. Ibid., 41.

15. “The Tunguska event,” http://web.utk.edu/~comet/papers/nature/TUNGUSKA.html.

16. Steel, Rogue Asteroids and Doomsday Comets, 44.

17. Vershuur, Gerrit L., Impact!: the threat of comets and asteroids, 166.

18. John & Mary Gribbin, Fire on Earth (Pocket Books, 1996), 37.

19. Atkinson, Impact Earth, 84.

20. Ibid., 3.

21. Ibid., 4.

22. Ibid., 6.

Comet Caesar – Dark Comet in 2012?

Dark Comet in 2012?

When beggars die there are no comets seen. The heavens themselves blaze forth the death of princes.
Shakespeare
Julius Caesar

When considering what might cause us grief in 2012, few if any researchers consider the start of the Mayan Long Count calendar to have any importance. This is surprising, because the reason for the calendar beginning on August 11 3114BC might contain clues about 2012 itself. After all, the Mayan culture did not exist 5,000 years ago, so either they randomly chose an ancient date on a whim, or an earlier civilization was behind the calendar, and they knew something important occurred on that date.

What could happen in 3114BC, and also in 2012AD? No civilization has lasted that long, so they are unlikely to be man-made events. Any natural events that occur so infrequently on Earth are virtually impossible to predict (volcanic eruptions for example). So that leaves us with astronomical events. The astrology of the pair of dates has been well studied, so we can rule out alignments of the stars and planets. That leaves the Sun, which we barely understand today, and comets. Is there a comet with a periodicy of 5000 years, due to return in 2012? Without any evidence from 3114BC it is impossible to say. Given that we are now near the end of the Mayan 5th age, could their calendar be designed to cover five orbits of a comet? And end catastrophically in 2012?

Most people have not heard of Comet Caesar (it doesn’t even have a Wikipedia entry), and hopefully this will remain so. However, if we are to suffer a terrible tragedy in 2012, it is currently my leading candidate, and the purpose of this article is to explain why.

Comet Caesar

Comet Caesar was the most famous comet of its day, and one of the brightest ever witnessed. It was visible during an annual Roman festival held in 44BC, shortly after Julius Caesar’s death. The following quotes are from The Greatest Comets in History: Broom Stars and Celestial Scimitars by David Seargent:

This was the comet that blazed in the skies of Rome following the assassination of Julius Caesar and which became immortalized by the Romans on the reverse of a coin bearing a portrait of Augustus struck in honor of the great Julius.

…According to Pliny, Octavian wrote that “On the very days of my games, a comet was visible over the course of seven days, in the northern region of the heavens. It rose at about the eleventh hour of the day and was bright and plainly seen from all lands”.

…In the fourth century of our era, Servius presented an account that had the comet visible for 3 days and visible at midday and during the daytime.

Comet Caesar is a parabolic comet – a comet that returns less frequently than every 200 years.
Most parabolic comets have orbits significantly longer than 200 years, and very few have ever been observed to make a complete orbit.[1] Astronomers expect 50 percent of parabolic comets will receive gravitational nudges that cause them to never orbit the Sun again. Those that remain in orbit should be slowed with each passage, eventually becoming intermediate or short-period comets.[2] Therefore we either never see them again, or they take so long to return that we don’t know which, if any, have historical records they match up with.

In my search for the most likely 2012 culprit, I have constantly asked myself, could the ancients have predicted this? Asteroids and comets are definitely predictable in a broad sense, and all that it takes is observation and mathematics. Such calculations are not easy. They require recalculating the orbit for every day of every year, according to where the object is then located, and how the planets are affecting its course. If ancient astronomers had considered the period of a comet or asteroid to be fixed, rather than varying due to the gravitational influences of planets, then there may have been inaccuracies in any 2012 prediction they made. However the daily recalculations were certainly not impossible in ancient times.

Predictability of Comets

Perhaps the most famous comet, even today, is Halley’s Comet. Edmond Halley – as well as a team of French mathematicians – predicted the return of this comet, not just from knowing the dates of its past visits, but by calculating the gravitational effects of planets like Saturn and Jupiter. They did this by hand.

A single line in the Talmud suggests that 1st century Jewish astronomers were also aware of the periodicy of Halley’s Comet:

“a star which appears once in seventy years that makes the captains of the ships err”.

To go from calculating the return of a comet, to having knowledge that it will probably strike Earth, is a major leap. Although that is not to say they weren’t merely predicting the return of a spectacular comet, let’s investigate the possibility that an ancient culture was capable of predicting the actual impact of a comet in 2012.

First of all, for this hypothesis to have any validity, the comet must be a long period one; that is, it must pass our planet less frequently than once every 200 years. More frequent comets would be well known by modern astronomers, and would most likely have their future orbits determined.

According to Wikipedia, there are just 40 known comets with a periodicy greater than 200 years (or non-periodic comets). Of these, 38 have been observed since 1577AD. The only prior dates were 1106AD and 44BC. To me this suggests that a great many earlier observations would have been made, we just don’t have evidence of such.
The Great Comet of 1106AD was seen from Europe to Japan. A Welsh text said of it:

In that year there was seen a star wonderful to behold, throwing out behind it a beam of light of the thickness of a pillar in size and of exceeding brightness.
http://en.wikipedia.org/wiki/X/1106_C1

Were we to have detailed records of comets from more historical times, we might have a similar description with which we could determine the periodicy of the 1106 comet. Without this, we have nothing to base its return on – could be tomorrow, could be never. [3]

You could say the same about Comet Caesar, the aforementioned earliest recorded comet of 44BC. Without another record of it, we cannot determine when it will return next. While there may not be any surviving record of a prior passage, perhaps we can make an implication from the Long Count calendar. If the end of the calendar is actually the date a comet will strike Earth, what is the most logical reason for the start date?

If, and this is obviously pure speculation, it had been observed in 3114BC, and again in 44BC, could it be returning once again in 2012? With a precise periodicy of 1025.2 years (which equals four Mayan Short Counts) we get the following sequence of dates:

3114BC – start of the Long Count calendar
2089BC – 2104/2105 is when the Great Flood occurred according to the Hebrew Calendar
1064BC – 1077 was the end of the Egyptian New Kingdom, marking the beginning of Egypt’s decline
39BC – Comet Caesar was witnessed in 44BC
987AD – Dark Ages
2012AD – end of the Long Count calendar

Is 39BC close enough to 44BC? In 1758 the French astronomers who calculated the return of Halley’s Comet determined that the gravitational effects of Saturn and Jupiter would make a difference of 618 days to its existing orbit, or almost 2 years. Is a difference of 5 years within 5 orbits outside the realms of possibility?

Variable Periodicy of Comets

When Comet Hyakutake was discovered in 1996, astronomers determined that on the way in to our solar system it had an estimated periodicy of 17,000 years, yet after having its orbit disturbed by the largest planets, its new course meant it would take between 72,000 and 114,000 years to return.

When 23P/Brorsen-Metcalf was first discovered it was closest to Earth in August 1847. After completing its orbit it was back in that approximate spot in October 1919, and again in August 1989. The two observed periods were 72 years and 70 years. That’s roughly a 3% deviation between 2 orbits.

The periodicy of a comet can vary from a little, to a lot, to so much we never see it again. It is entirely possible that Comet Caesar was seen the very same years as the Great Flood, the end of the Egyptian New Kingdom, the start of the Long Count calendar – and will return in 2012.

Where are the records?

…they were either not observed or were observed and recovered by illiterate, uneducated peasants. It was quite unthinkable that the sophisticated urban theologian of A.D. 1000… should take seriously the allegations of such rabble that stones fell from the sky.

…Modern astronomers seeking accounts of ancient astronomical events …find the records of medieval Europe sparse at best.[4]

To explain the absence of records for Comet Caesar prior to 44BC is easy – lost in the annals of history that never made it. But what of 987AD? Could it really go from observed in 44BC, to not observed at all? Or has the record from 987AD +/-3 years, just disappeared?

The former possibility is covered by the concept of dark comets, described below. To answer the latter possibility, 987 was in the Dark Ages, renowned for a lack of records. In fact so lacking that some researchers have speculated that the era never existed at all!

Halley’s Comet was observed in 837 according to records from Japan, China, and Germany. The next observation was in 912, and was recorded in the Annals of Ulster, like this: “A dark and rainy year. A comet appeared”. There is no specific record of its return in 990, and was next spotted in 1066, where it was recorded as having an influence on the Battle of Hastings.

The only mention of a comet circa 987AD (when I approximately hypothesize Comet Caesar would have returned) is indirect, and attributed to Eilmer of Malmesbury, a Benedictine monk:

You’ve come, have you? – You’ve come, you source of tears to many mothers. It is long since I saw you; but as I see you now you are much more terrible, for I see you brandishing the downfall of my country
http://en.wikipedia.org/wiki/Eilmer_of_Malmesbury

He described this appearance in 1066. Because the previous passage of Halley’s Comet would have been in 990AD, and he was an “old man” in 1066, it is believed that he could have seen the comet when he was 5 years old, and have would been 76 years old in 1066 when he was quoted. But what if he was just a few years older in 1066, and was actually recalling a comet he witnessed in 987AD? Could he have seen the most recent passing of Comet Caesar, and not Halley’s Comet, in the closing years of the tenth century?

Taking a different angle, if there is no specific record of Halley’s Comet in 990AD, it fits that a return of Comet Caesar circa 987AD also avoided any record that survives to this day.

For some, a simple lack of record will suffice, and the hypothesis is feasible. For the others, I will describe a mechanism from which the comet rapidly loses visibility.

Dark Comets

There’s only one difference between dark comets and regular comets – we won’t see the approach of the dark comet.

In early 2009 many news articles reported the findings of British astronomers Bill Napier (Cardiff University) and David Asher (Armagh Observatory), and reading them sent a shiver down my spine, prompting me to research the possibilities further.

“There is a case to be made that dark, dormant comets are a significant but largely unseen hazard,” says Napier.

…periodic comet showers appear to correlate with the dates of ancient impact craters found on Earth, which would suggest that most impactors in the past were comets, not asteroids.

Now Napier and Asher warn that some of these comets may still be zipping around the solar system. Other observations support their case. The rate that bright comets enter the solar system implies there should be around 3000 of them buzzing around, and yet only 25 are known.[5]

Until now it was commonly accepted that more than 90% of meteors and comets that could cause us harm were known and tracked by astronomers and government agencies. That thousands of comets that are potentially heading straight for us are not known or tracked is rather frightening. How can a comet become dark?

The science is actually quite easy to understand. Comets start out with ice on their surface. Every time they orbit around the Sun, the heat melts some ice. Eventually there is no ice left. And the only way we can easily see comets is from light reflecting off the ice.

In 1983, Comet IRAS-Araki-Alcock passed by Earth at a distance of 5 million kilometres, the closest known pass by any known comet for 200 years. It was spotted only two weeks ahead of its closest approach. “It had only 1 per cent of its surface active,” says Napier. Comet Borrelly, visited by NASA’s Deep Space 1 probe in 2001, was found to have extremely dark patches over much of its surface.[6]

Clark Chapman, from the Southwest Research Institute in Boulder, Colorado, is not so concerned, saying that the dark comets ‘would absorb sunlight very well’ and therefore should be possible to detect from the heat they would emit. I’m not qualified to judge this statement, but from a layman’s point of view, I would think a hand-held mirror reflecting the sun’s light from a mile away is far more easily seen than a slab of rock that is so hot you could fry an egg on it.

Here are a couple of examples of lost comets. One of the reasons they are no longer observed could be that they have lost their luminosity.

18D/Perrine-Mrkos – seen in 1896 and 1909, then 1955, then 1969, and not since.
5D/Brorsen – first spotted in 1846, last seen in 1879. With an orbital period of 5.5 years. Has been as close as 0.52 AU to Earth, and as far as 1.5AU. Japanese astronomers hoped to spot it in 1976, but failed.

The orbital period of 5D/Brorsen suggests it could be passing by in 2012, if it is still on course. There is even a possible case of a dark comet harming us (in a roundabout way) in recent times. Paul Wiegert of the University of Western Ontario has determined that the dark comet D/1895 Q1 (Swift) interacted with NASA’s Mariner 4 Mars probe in 1967. Given that the comet was only ever observed in 1895/1896, there is not enough data to be absolutely certain, but something interacted with the probe, and a dark comet is the leading candidate.

Many lost comets could be coming close to Earth in 2012, but without recent observations, there is no way of accurately calculating their passage.

A long period comet would be the best candidate for a 2012 culprit for two reasons:

an ancient civilization may have tracked comets for much longer than our present civilization, giving them a great advantage in determining the periodicy of long period comets
a longer period that adds up to a 2012 rendezvous is more statistically reliable than that of a short period comet. Every passage increases the chance of permutations due to encounters with the gravity of planets it may pass. A comet that has orbited 4 times in the last 2000 years is more likely to still be on course than one that has orbited unseen 50 times in the last 200 years.

Summary

Even without the possible return of Comet Caesar, dark comets are the leading contender for triggering a predictable 2012 cataclysm. Comets were known to the ancients – we have many ancient texts providing us with descriptive names like “fire from the sky” – and their cyclical nature makes it easy for any civilization with mathematical prowess to predict. Thousands of hypothetical dark comets remain undiscovered in modern times, and if we do find one on a collision course with our planet, we may only have a few years, or even a few days, to prepare. And those times will be times of mass panic.

Notes

1. Steel, Rogue Asteroids and Doomsday Comets, 25. The longest observed orbital period for a comet is 153P/Ikeya-Zhang with 341 years, having been discovered in 1661, and again in 2002.

2. Gribbin, Fire on Earth, 103

3. Of course there is the possibility that the Great Comet of 1106AD and the 44BC comet are one and the same. If that were true, it could be expected to return circa 2250AD.

4. Lewis, Rain of Fire and Ice, 17

5. Parsons, “’Dark’ comets may pose threat to Earth.”

6. Ibid.

Addendum

Teleilat Ghassul is located in the Jordan Valley near the Dead Sea is an important site from the Chalcolithic period. Many of the mud brick homes that have been unearthed featured remarkable wall paintings. Paintings were not permanent – it was common for old paintings to be coated with a white lime plaster, and new paintings taking their place. Up to 20 successive layers have been found. Perhaps this 2-metre mural was kept because it represented an important or memorable event:

This is pure speculation, but just as the coin depicted above used an eight-pointed star to represent Comet Caesar, perhaps this is a record of the same comet, but from a different era? For the idea to have any merit, a date for the mural should fit closely the dates I have listed for any previous returns there may have been – 1064BC, 2089BC or 31143BC.

Various radiocarbon dates have been taken from the site, from dung, cereal and wood, and those dates suggest that the occupation lasted roughly 1000 years, ending at approximately 3800BC. The paintings themselves do not seem to have been dated, nor would there be any reason to do so. One must conclude that the most likely date for the painting would be during the period of occupation, so possibly it represents the return of Comet Caesar prior to 3114BC, somewhere around 4139BC.

There are also two comet images at Megiddo, and these have been assigned a date of Early Bronze Age I, which is 3300-3000 BC in the Near East, and fits our 3114BC date perfectly. They were found on paving stones. The broom shape is actually a very common way of depicting comets in many ancient cultures, including the Chinese.

The broom shape is actually a very common way of depicting comets in many ancient cultures, including the Chinese.

Furthermore, a controversial theory suggests a major asteroid impact dated 3123BC, extremely close to the start of the Long Count calendar.

Cosmic Rays

What are cosmic rays?

The base structure of all things is the atom. Atoms are full of movement, both internally (electrons orbiting the nucleus) and externally (interacting with other atoms). This movement creates kinetic energy that is measured in electron volts (eV). The atoms of the air we breathe move as fast as cannonballs and generate around 0.03 eV. They bounce into other atoms of air but, like bumper cars at a fairground, they don’t do much harm to each other.

Elsewhere we find atomic particles moving much faster than this, which create more heat and more energy. Electrons within the Sun’s plasma have up to 10,000 eV, and protons in the magnetosphere [*] are higher still, in the range of 10 – 100 million eV. [1] The atomic particles in the magnetosphere move at speeds of 400-800 kilometres per second.

This is all rather calm relative to the greater universe. Bombarding the Earth from light years away are the ions we call cosmic rays. [†]. They can move close to the speed of light and can pack a walloping 50 joules of kinetic energy (3 × 10²⁰ eV). That’s the power of a cricket ball moving at 160 km/h, packed into the size of a sub-atomic particle.

Most cosmic rays are the nuclei of atoms (protons), ranging from the lightest to the heaviest elements in the periodic table. The lightest elements are the most common, with hydrogen (89%) and helium (10%) dominating, along with other light elements (lithium, beryllium and boron). A few will be medium elements like carbon or oxygen, with heavier elements becoming less and less common. This is a similar relative abundance to the elements within our solar system. [2]

Who discovered them?

In 1912 Austrian-American physicist Victor Hess found that his electroscope discharged more rapidly as he ascended in a balloon. He theorised that there must have been radiation entering our atmosphere from outer space, which he dubbed cosmic rays. In 1936 he was awarded the Nobel Prize for his discovery.

Where do they come from?

Cosmic rays hit Earth from every direction, but this tells us nothing of the location of their original source. Because they are magnetically charged, any interaction with a magnetic field, even an extremely weak one, will change their path. They are constantly deflected by magnetic fields throughout the galaxy, until any clues to their origin is lost. (However, it is possible to trace cosmic rays in other regions of the galaxy by the electromagnetic radiation they produce). [3]

Within our local planetary system the solar wind creates a magnetic field of its own. This makes it difficult for cosmic rays to make it to Earth – there is a correlation between the peak of the sunspot cycle and fewer cosmic rays reaching Earth. [4]

We don’t know where all the cosmic rays come from. The Sun emits low energy cosmic rays, typically accompanying solar flares. But even if every star in the known universe created cosmic rays in a similar manner, they would only explain a fraction of them.

The majority are believed to come from supernova explosions [‡] , which occur approximately once every 50 years in our Galaxy. They either originate from the explosion itself, or are created by the shock waves interacting with the surrounding interstellar gas. This reasoning is based on the energy requirements for creating cosmic rays, with only supernovas being deemed powerful enough to make them. In both cases the ejected matter expands at supersonic velocities, accelerating nuclei from the material they pass through, transforming them into cosmic rays.[5]

Other sources could be neutron stars, radio galaxies, X-ray binaries (such as Cygnus X-3), active galactic nuclei (AGNs) and black holes.

To measure cosmic rays directly, before they have been slowed down and broken up by the atmosphere, particle detectors can be placed on spacecraft and high altitude balloons.[6] Or they can be detected indirectly on our planet’s surface. When cosmic rays collide with atoms in the upper atmosphere, they create secondary particles (pions, electrons, positrons) which shower down to the Earth, spreading out over hundreds of metres. A grid of a hundred or so detectors is used to sample this area. The more particles that are detected, the stronger the cosmic ray. The atomic number of the cosmic ray’s nucleus cannot be discovered using this technique, just statistics of size and frequency. The biggest registered so far, a 50-joule cosmic ray, was at a Utah desert observatory in October 1991. On average one of this size will enter our atmosphere every second.

The world’s biggest cosmic ray observatory is being built in Argentina and will be operational in 2004.

Cosmic rays of this size are labelled “ultra high-energy”. To date, scientists have been unable to determine the limits of the cosmic-ray spectrum, simply because they lack a detector large enough. The more powerful the particle, the less common it is, and the larger a detector needs to be to spot it. So even when the galaxy is quiet, there may be much larger cosmic rays hitting Earth and going undetected.

Ultra high-energy cosmic rays are a puzzle for scientists. Astrophysicists have decided that only black holes of a billion solar masses would have the energy to create them. Because interaction with the universal microwave background (remnants of the Big Bang) causes them to lose energy, their source cannot be more than 30 million light-years away. But within our own galaxy there are no known mechanisms to create such powerful particles. [7] An obvious answer comes to mind that most scientists will have difficulty accepting, that something within our galaxy – that has yet to be observed – could create them.

It is understandably hard for us to recreate the conditions of the cosmos here on Earth. The most modern artificial vacuums do not come close to achieving the emptiness of space, which has a density as low as one atom per cubic centimetre. Because ultra high-energy cosmic rays move close to the speed of light, time-scale adds to the problem. If we could observe a cosmic ray for 10,000 years, from the particle’s point of view only one second will have passed [8] . Viewing it for a microsecond in a particle accelerator will not tell us much. The complicated electrical and magnetic fields of outer space add to the difficulties. So, even if we can estimate where cosmic rays come from, we have no idea how they are created. And the time scales are impossible to recreate. Guesses and theories abound. Definitive answers do not.

Is the rate of bombardment constant?

No. This is one reason why carbon dating (http://www.sigmaxi.org/amsci/articles/00articles/taylorcap2.html) (the carbon isotopes they measure are created by cosmic rays) is inaccurate, because it assumes that the rate is a constant, which is a typical gradualist way of looking at things. Evidence from a half-metre long stalagmite that grew between 45 000 and 11 000 years ago in a cave in the Bahamas, shows that the cosmic ray intensity for that period was double what it is today – see here or here for more info.

What happens when they hit earth?

The combined energy of all the cosmic rays approaching Earth is massive. Fortunately the atmosphere and magnetosphere [§] protect us from them as effectively as a slab of concrete four metres thick. Even so, when cosmic rays collide with atoms in the upper atmosphere, they release showers of gamma rays, X-rays and subatomic particles. Most of these secondary particles will make it to the Earth’s surface. And the most energetic fragments, although rare, are capable of penetrating miles underground. [9]

Atomic structures mainly consist of space – space between the nucleus and electrons, space between the individual atoms. Because of this, sub-atomic particles can travel a great distance before they collide with anything. Consequently most cosmic rays and secondary particles pass right through houses, trees, rocks, birds and humans. But a few will occasionally crash into atoms within these structures and beings. Don’t be too alarmed; this cosmic radiation is minor compared to the Earth’s natural background radiation, which in total hardly affects any of us at all anyway.

Thousands of rays and fragments pass through our bodies every minute. [10] Outside of the Earth’s atmosphere, where some satellites and astronauts roam, cosmic rays are very dangerous indeed – their sheer frequency means they can ionise electronic circuitry and mutate the genes of astronauts.

How dangerous is flying?

Altitude matters. Whether you are flying in an airplane or living at a high altitude such as Tibet – the amount of cosmic radiation your body must deal with is increased.

During solar radiation storms, passengers on jets flying nearer Earth’s poles can get zapped with than the equivalent of 10 chest X-rays

A 1996 paper in the American Journal of Epidemiology examined the incidence of cancer among 2,740 Air Canada pilots. The group had a sharply higher incidence of four specific types of cancer compared to the general population: myeloid leukemia, astrocytoma, prostate cancer, and malignant melanoma.

Myeloid leukemia is definitely associated with radiation exposure, and occurred in the Air Canada pilot group four times more frequently than in the general population. A Danish study also found an association between exposure to cosmic radiation and leukemia among aircrew – it was published in Lancet 1999; 354: 2029-31
Astrocytoma (a type of brain cancer) occurred twice as often in the Air Canada pilot group as in the general population, and increased incidence has also been found in other studies of airline pilots.
Significantly higher incidences of prostate cancer were found in both the Air Canada study and another study of British Airways pilots. Current thinking is that this might be related to electromagnetic radiation from weather radar and other avionics rather than from cosmic radiation.
A study of female airline flight attendants in Finland and Denmark showed an increased incidence of breast cancer, and a study of male U.S. Air Force pilots showed they had significantly more genital and testicular cancer than non-flying USAF officers.

In 2000, the European Union introduced legislation which requires all European airlines to monitor cosmic radiation levels during flight and to inform aircrew of the possible health risks.

NASA says:

“Airline pilots, crew, and passengers definitely are hit by more cosmic radiation than someone on the ground. The radiation is stronger at higher altitudes, and especially over the poles. Individual flights are almost certainly not a problem, since the radiation will never get anywhere near the 2.5 millirem per hour maximum allowable radiation
dose (OSHA) even for a 41,000 ft flight right over the poles. But it is possible that pilots and crew accumulate enough to slightly increase their cancer risk. A Finnish study showed a higher breast cancer rate for stewardesses than for non-stewardesses, but there are other environmental factors (air quality for instance) that could affect this.

The weight of shielding required to protect against this radiation would make these flights nearly impossible. So there’s not really anything you can do except decide not to fly.”

The invisible passenger : radiation risks for people who fly by Robert J. Barish

Time Magazine – JULY 9, 2001, VOL.158 NO.1

“Yet to become a legal issue is the worry over cosmic radiation. According to the Federal
Aviation Administration, at 12,000 m air travelers are exposed to as much as 265 times the radiation dose they receive on the ground. Some airlines take pregnant female flight attendants off airborne duties to avoid exposing the fetus to cosmic rays. Passengers who make a transpolar journey, like the new direct Hong Kong-New York routes operated by Continental Airlines, United Airlines and, from September, Cathay Pacific, receive on average the equivalent to three chest X rays. (The rays concentrate around the North Pole’s magnetic attraction.) Five round-trips on these flight paths would put the traveler in excess of the recommended annual limit for exposure to radiation, experts say. Already, since the flights commenced in March, Continental and United have rerouted one each, Continental citing passenger health concerns, United radio interference from solar radiation. (United said last week it was canceling its flight from next month for business reasons.) Maria Blettner, head of Germany’s Radiation Protection Commission, is finishing a large-scale mortality study on cancer among flight crews, which is examining the medical history of 22,000 pilots and 50,000 flight attendants. Results are due soon, but Germany’s Cockpit Association, a professional organization of pilots and engineers, warns the findings will reveal breast-cancer rates among stewardesses may be twice as high, and skin-cancer rates up to 15 times as high as those of the general populace.”

Should I worry?

Although you can’t feel them, cosmic rays, and/or their secondary particles, pass through you all the time. Mostly they won’t touch the sides. But, occasionally they will connect with one of your atoms, and, if your DNA repair system doesn’t kick in, you might in some way mutate. Standard theories of Darwinian evolution always mention random mutations, but rarely point
out the mechanism behind them – cosmic rays are a leading cause.

At current levels, unless you are a pregnant frequent flier, there are many, many other factors in your daily life that do you more harm. But if the level of cosmic ray bombardment increases – as it has done in the past – it might be prudent to investigate ways of shielding yourself from them.

Links:

Cosmic Ray Deflector Society (not serious)

Cosmic Ray Intensities at Major Cities Worldwide (bottom of the page)

Online Cosmic Ray Detector

High Altitude Radiation Monitoring Service

Radiation detector and software

Radioactive Products and Household Sources Of Radiation

Dosimeters – for measuring an individual’s exposure

Radiation exposure for aircrew – a big article from AVWeb

Using the Moon as a cosmic ray detector

Downloadable program – allows flight crew to calculate their levels of exposure

[*] Magnetosphere: area surrounding the Earth that is influenced by its magnetic field. Towards the sun it extends for 60,000 kilometres, and away from the sun it forms a tail, created by the solar
wind, with a length of one million kilometres

[†] The term “cosmic ray” is misleading. Rather than being an actual ray (a thin beam of radiant energy or particles), it is just a singular particle – anatom that was stripped of its electrons when accelerated to enormous speeds.

The cosmic rays referred to here are more properly known as Galactic Cosmic Rays. The general term can also includes subatomic particles like electrons and positrons, particles arriving from the sun and particles accelerated in interplanetary space.

[‡] A supernova is a star which has run out of the “nuclear fuel” of light elements (especially hydrogen), needed to keep it shining. Its “nuclear burning” gradually converts light elements into heavier ones, and the heat it produces keeps the star puffed up, resisting the pull of gravity which would like to draw it together. When the star can no longer produce nuclear heat, it suddenly collapses to a small volume, releasing in the process an enormous amount of gravitational energy. Much of that energy is spent in a grand explosion, blowing the star’s outer layers out to space and creating a huge expanding shock front. (from a NASA website)

[§] The active sun with its large solar wind creates a large distortion of the magnetic field about the earth (the magnetosphere), which increases the earth’s shielding against intragalactic cosmic rays. This leads to a net reduction of the sea-level cosmic rays during the period of the active sun. In the active sun of 1989-1991, which was the most intense solar activity ever recorded, the sea-level intensity of cosmic rays actually decreased by about 30%. Thus, the active sun greatly intensifies the solar wind, and the external particle flux increases, but the earth’s distant magnetic field also increases. The final result of this complex interaction is that the terrestrial sea-level flux of cosmic particles decreases during the active
sun, except for the few hours during the most spectacular solar flares (from http://www.research.ibm.com/journal/rd/421/ziegler.html)

[1] http://www-spof.gsfc.nasa.gov/Education/wcosray.html

[2] http://www.srl.caltech.edu/personnel/dick/cos_encyc.html, Macmillan Encyclopedia of Physics in 1996. R. A. Mewaldt, California Institute of Technology

[3] Macmillan Encyclopedia of Physics in 1996.

[4] Macmillan Encyclopedia of Physics in 1996.

[5] “Cosmic Rays at the Energy Frontier,” Microsoft® Encarta® Encyclopedia 2000. © 1993-1999 Microsoft Corporation. All rights reserved. By James W. Cronin, Thomas K. Gaisser and Simon P. Swordy About The Authors: Cronin, a professor of physics at the University of Chicago since 1971, shared the Nobel Prize with Val L. Fitch for work on symmetry violations in the decay of mesons. Gaisser, a professor of physics at the University
of Delaware. Swordy, an associate professor at Chicago, has been active in cosmic-ray measurement since 1976. He earned his Ph.D. from the University of Bristol in 1979. This article updates a version that appeared in Scientific American in January 1997.

[6] Macmillan Encyclopedia of Physics in 1996.

[8] Einstein’s Theory of Relativity

[9] http://www-spof.gsfc.nasa.gov/Education/wcosray.html

[10] Macmillan Encyclopedia of Physics in 1996.

Eta Carinae Supernova in 2012?

Eta Carinae

Click here to see a much bigger version of the above image, or find many more Chandra images of Eta Carinae

Read about the possibilities of Eta Carinae going hypernova…

What We Know…

According to the Universal Book of Astronomy, Eta Carinae is:

One of the most massive and remarkable known stars; it lies in the constellation Carina. Surrounded by the largest diffuse nebula in the sky, the Eta Carinae Nebula, it is an S Doradus star with a mass of over 100 Msun and a luminosity of about 4 million Lsun, putting it close to the theoretical limit of stellar stability. Only by shedding matter at the prodigious rate of 0.1 Msun per year has it managed to stay in one piece so far. Its variability is extraordinary.

In 1843, it reached a visual magnitude of -1, making it, briefly, the second brightest star after Sirius, despite its distance of some 7,500 light-years. Accompanying this visual brightening was an expulsion of 2 to 3 Msun of material from the star’s polar regions. This material, spewed from the star at speeds close to 700 km/s, formed two large, grayish, bipolar lobes, nicknamed the Homonculus Nebula, that have been photographed in spectacular detail by the Hubble Space Telescope. Each lobe currently expands at a rate of 2.4 million km/hr and spans about 6.4 trillion km.

After the great eruption of the mid-nineteenth century, Eta Car faded in spurts to below naked-eye visibility, settling at about seventh magnitude. Recently, it has started to brighten again, gaining a full magnitude from 1950 to 1992 and is continuing its ascent. Eta Car emits powerfully across a range of wavelengths. At some infrared wavelengths, the star and its nebula are the brightest objects in the sky beyond the Solar System. The mid-infrared emission originates in dust ejected by the star during giant mass-loss events within the past several hundred years. X-rays come from an outer, horseshoe-shaped ring with an electron temperature of about 3 million K, that is about 2 light-years in diameter and was probably caused by an outburst that happened more than a thousand years ago. Regular, small-scale variations in the star’s ultraviolet and X-ray output, with a period of 5.5 years, have led to the suggestion that Eta Car is actually a binary star. According to this theory, previous eruptions may have been due to the orbital interactions of the two stars. As for the star’s powerful X-ray emission, most astronomers agree that this is the result of the collision of two dense stellar winds, but whether these emanate from the two stars of a close interacting binary system or from the fast and slow stellar winds of a single star remains unclear. One thing seems certain: Eta Carina is doomed to explode as a supernova in the not-too-distant future.[1]
[emphasis added]

[1] The Universal Book of Astronomy, David Darling, Published by John Wiley & Sons, New York, October 2003