A comet that survived the fires of the sun
The title of this blog sounds like something from a science fiction novel. But it is true and took place this month in our solar system. A comet, which is basically a rock of frozen dust from the outer reaches of our solar system, passed within 80,000 miles of the sun’s surface and entered the corona, a region surrounding the sun where temperatures can reach over 1 million degrees. There goes the frozen snowball, right? Wrong. The comet survived, came out of its close approach with the sun, and has put on a spectacular show in the skies of the Southern Hemisphere.
The comet was discovered by Australian amateur astronomer Terri Lovejoy in November of this year. After he spread the word within the astronomy community, other astronomers were able to track the comet and determine its orbit. This was a Kreutz comet, meaning a sungrazing comet, named after the 19th centrury German astronomer Heinrich Kreutz. Kreutz’s theory states that all sun-grazing comets, i.e. those passing very close to the sun in their orbit, are all part of a larger comet that broke up centuries ago. Some sungrazers don’t survive their perihelion (closest approach) to the sun and are pulled into the sun by strong gravitational forces and destroyed. But others survive.
Comet Lovejoy as photographed in Perth, Australia by Colin Legg in late December 2011. This is a 13 second exposure using a 70mm f/4 lens, ISO 3200.
Comet Lovejoy, with a perihelion distance estimated to be somewhere around 75,000 miles, was expected to burn up and be destroyed. How could an icy snowball pass that close to the solar surface and live to tell about it?
Lovejoy’s perihelion was monitored by several space-bound telescopes which tracked the inbound path. Much to the delight of observers the comet appeared from behind the sun after perihelion and is now on an outbound orbit.
The huge tail of the comet is visible rising before sunrise in the Southern Hemisphere, and the view from the International Space Station was incredible. View the videos below for breathtaking examples of Lovejoy’s beauty. Unfortunately we can only watch on video. Here in the Northern Hemisphere we are unable to see such a spectacle.
Video from SOHO and LASCO spacecraft observing the comet approaching and then moving away from the sun. Note the tail of the comet always points away from the sun. Watch it HERE.
The view of Comet Lovejoy as seen from the International Space Station, followed by a brief interview with Commander Dan Burbank who shot the video. Watch it HERE.