25 December 2011
Comet Lovejoy photographed onboard the International Space Station
Credit: NASA/Dan Burbank
NASA recently published a beautiful image of the bright Comet Lovejoy, taken by an astronaut, onboard the International Space Station (ISS). The image shows the comet shining over the night side of Earth, whose atmosphere glows in fascinating hues. The ISS is the largest spacecraft ever launched into space. It orbits Earth at an altitude of about 350 km.
Close-up view of Comet Lovejoy
Credit: NASA/Dan Burbank
Comet Lovejoy, technically designated C/2011 W3, was discovered on 27 November 2011, by amateur astronomer Terry Lovejoy. It is a periodic comet that has approached the Sun too closely. On 16 December 2011, this comet ventured into the solar corona, the Sun’s tenuous hot outer atmosphere, and passed within approximately 140,000 km, about 1/1000 the average Earth-Sun distance, from the surface of the Sun, when it reached its minimum distance from the Sun.
Astronomers did not expect Lovejoy would endure its deep plunge into the corona, but NASA’s Sun-orbiting SDO spacecraft observed the comet, while it was hurtling out of the corona.
Comet Lovejoy belongs to a category of comets, named Kreutz Sungrazers, after their discoverer, German astronomer Heinrich Kreutz (1854-1907). The Kreutz Sungrazers are believed to be fragments of a large shattered comet. They often disintegrate by Sun’s radiation, as their orbits bring them extremely close to the Sun. However, large Sun-grazing comets, like Lovejoy, may survive the fateful encounter.
References
NASA
www.nasa.gov/
Wikipedia
Aymen Mohamed Ibrahem
Senior Astronomy Specialist