2013 - year of the comet?

Sun-Grazing Comets As Triggers For Electromagnetic Armageddon

Large sun-grazing comets could bring on the sort of global electronics meltdown usually associated with electromagnetic pulse weapons or a full-scale nuclear exchange.

Forbes,

30 November, 2012

Or so says David Eichler, lead author of a forthcoming Astrophysical Journal Letters paper positing that a sun-grazing comet roughly the size of Hale-Bopp (with a nucleus some 30 kms in diameter), could trigger cosmic ray-generating shockwaves large enough to initiate a global electromagnetic Armageddon.

Eichler, an astrophysicist at Israel’s Ben-Gurion University of the Negev in Beer-Sheva, argues that satellites that weren’t in protection mode would be wiped out along with most of the world’s electronics — everything from micro-circuitry on cell phones to full-scale power stations.

If such a comet were the size of Hale-Bopp, Eichler says, the resulting solar flare would by far be the largest ever observed.

The comet gets compressed and then explodes in the solar atmosphere which, in turn, creates shockwaves, says Eichler.

Eichler thinks that such a sun-grazing comet may have triggered a large solar flare and cosmic ray-generating shockwaves as recently as 775 A.D., as indicated by tree ring analysis pointing to a sudden 1.2 percent spike in atmospheric Carbon 14.

“I’m not saying that [event] couldn’t have been caused by a magnetic solar flare, but we’ve never seen a solar flare nearly that big,” said Eichler.

Although the motion of such a sun-grazer would be the source of the shockwaves’ energy, the actual particle acceleration would happen within the sun’s magnetic field, explains Eichler.

Traveling at a 1000 kms per second, the shockwaves would reach earth in about a day and a half. And the effects would likely be much worse than the 1859 Carrington Event, a solar superstorm that wreaked havoc on telegraph lines and caused the aurora borealis to be visible as far south as Texas.

“From the looks of the tree ring data, fortunately, such events don’t happen but once every several thousand years,” said Eichler. “But by my estimates such a comet event might be 30 times stronger than the Carrington Event.”

Such a sun-grazing event’s resulting volley of cosmic rays would be funneled in along earth’s magnetic poles where magnetic resistance is the least, Eichler explains.

When the shockwaves hit the earth’s magnetic field, it would be like the hammer of a piano hitting a string, says Eichler. It would vibrate. And when a magnetic field line vibrates, he says, it makes an electric field which excites current in wires.

“It can excite the current and burn out the circuit,” said Eichler. “That’s the danger of giant electromagnetic pulses; these huge electric fields hit tiny micro-circuitry designed to handle only small currents.”

Although not expected to be harmful to humans, such an event could be extremely devastating to our electronic grid and could quite possibly send us back into a new Stone Age, says Eichler.

As for predicting future sun-grazers?

Most sun-grazing comets are too small to even make a ripple on the solar surface.

A recent exception was Comet Lovejoy, a long period sun-grazing comet which in December 2011, was observed to unexpectedly survive its closest solar approach.

Eichler says it’s quite possible that a very large comet could graze the sun once every several thousand years.

“If the Hale-Bopp-sized comet grazed the solar corona,” said Eichler, “then you’d get a much bigger solar flare than the Carrington Event. Hale-Bopp itself may become sun-grazing in the [distant] future.”

But there is one positive. Astronomers should, in principle, get a few years notice if such a large potential sun-grazing comet comes around again.

However, with a few classified military exceptions, our electronics remain unprotected against such potential magnetospheric trauma, he says.

Today, the Carrington Event itself would be devastating, says Eichler, and it wasn’t particularly powerful or all that unusual on an astrophysical timescale.

After completing his research, Eichler says he is most surprised by the fact that we’re still here to tell the tale.

“I didn’t realize the solar system was such a dangerous place,” said Eichler. “Just the fact that we’ve gone as long as we have without worse things happening may be why we’re here.”

Orbital diagram and current position of Comet C/2012 S1 (ISON). The comet is at approx. magnitude 18 and located about 6.25 AU from the Sun. Could this brighten into one of the brightest comets ever? It’s possible. It is possible that this comet could develop a spectacular tail or briefly approach the brightness of the full Moon toward the end of 2013. Alternatively, the comet could break up when it gets closer to the Sun. The comet was discovered by Russian scientists Vitali Nevski (Belarus) and Artyom Novichonok (Russia). It is currently approaching the Sun from between the orbits of Jupiter and Saturn. Comet ISON appears on course to achieve sungrazer status as it passes within a solar diameter of Sun’s surface in November 2013. Whatever survives will then pass nearest the Earth in late December 2013. Astronomers around the world will be closely tracking this large snowball to better understand its nature and how it might evolve during the next 15 months. (Image Credit: JPL)

Comet Nearing The Earth In 2013 May Be Brighter Than The Moon, Researchers Say

A recently discovered comet that is rapidly approaching the Sun could outshine the Moon in 2013, researchers think. The comet may even be visible in daylight, as the Great Comet of 1680 was. It’s expected to be visible towards the end of the year, roughly from October until the following January

Planet Save,

30 November, 2012

“The recently discovered object, known as comet ISON, is due to fly within 1.2 million miles (1.9 million km) from the center of the sun on Nov. 28, 2013 said astronomer Donald Yeomans, head of NASA’s Near Earth Object Program at the Jet Propulsion Laboratory in Pasadena, Calif.”

“As the comet approaches, heat from the sun will vaporize ices in its body, creating what could be a spectacular tail that is visible in Earth’s night sky without telescopes or even binoculars from about October 2013 through January 2014.” With such a bright object in the night sky during the latter part of the year, it may somewhat drown out what will otherwise be a spectacular year of meteor showers in 2013.

The comet will need to survive its approach to the Sun though, for that to happen. And it’s possible that the comet could disintegrate as it gets close to the sun.

Comets like ISON originate from the Oort Cloud, which is a vast area full of frozen rocks and ice near the edge of the solar system. They orbit around 50,000 times further away from the Sun than the Earth does. Occasionally, some of these objects bump each other out of orbit, and are pushed into a spiraling orbit towards the Sun.

“On Sept. 21, two amateur astronomers from Russia spotted what appeared to be a comet in images taken by a 16-inch (0.4-meter) telescope that is part of the worldwide International Scientific Optical Network, or ISON, from which the object draws its name.”

“The object was slow and had a unique movement. But we could not be certain that it was a comet because the scale of our images are quite small and the object was very compact,” astronomer Artyom Novichonok, one of the discoverers, wrote in a comets email list hosted by Yahoo.

“Novichonok and co-discoverer Vitali Nevski followed up the next night with a bigger telescope at the Maidanak Observatory in Uzbekistan. Other astronomers did likewise, confirming the object, located beyond Jupiter’s orbit in the constellation Cancer, was indeed a comet.”

“It’s really rare, exciting,” Novichonok wrote.

Interestingly, comet ISON is following a very similar path to the famous comet of 1680, which was bright enough to be visible in the middle of the day. It is following such a similar orbit that researchers theorize that they may both originate from the same fragmented parent body.

“Comet ISON could be the brightest comet seen in many generations – brighter even than the full moon,” wrote British astronomer David Whitehouse.

“In 2013, Earth has two shots at a comet show. Comet Pan-STARRS is due to pass by the planet in March, eight months before ISON’s arrival. The last comet to dazzle Earth’s night-time skies was Comet Hale-Bopp, which visited in 1997. Comet 17P/Holmes made a brief appearance in 2007.”

Some more information on the comet of 1680:

“C/1680 V1, also called the Great Comet of 1680, Kirch’s Comet, and Newton’s Comet, has the distinction of being the first comet discovered by telescope. Discovered by Gottfried Kirch on 14 November 1680, New Style, it became one of the brightest comets of the 17th century – reputedly visible even in daytime – and was noted for its spectacularly long tail. Passing only 0.42 AUs from Earth on 30 November, it sped around an incredibly close perihelion of 0.0062 AU (930,000 km; 580,000 mi) on 18 December 1680, reaching its peak brightness on 29 December as it rushed outward again. It was last observed on 19 March 1681. As of September 2012 the comet was about 253 AU from the Sun.”

“While the Kirch Comet of 1680-1681 was discovered and subsequently named for Gottfried Kirch, credit must also be given to Eusebio Kino, the spaniard Jesuit priest who charted the comet’s course. During his delayed departure for Mexico, Kino began his observations of the comet in Cadíz in late 1680. Upon his arrival in Mexico City, he published his Exposisión Astronomica de el cometa in which he presented his findings. Kino’s Exposisión astronómica is among the earliest scientific treatises published by an European in the New World.”

“Although it was undeniably a sungrazing comet, it was probably not part of the Kreutz family. Aside from its brilliance, it is probably most noted for being used by Isaac Newton to test and verify Kepler’s laws. Some of the orbital elements of comet C/2012 S1 are similar to that of the Great Comet of 1680, which suggests the two comets may have fragmented from the same parent body.”