Incoming Comet to Blaze Over Earth
A veteran NASA comet probe turned its sights on a new target, comet C/2012 S1 (ISON), which is barreling toward a close encounter with the sun this fall.
Though Comet ISON is still more 470 million miles away (located just inside the orbit of Jupiter), it already has formed a tail of glowing dust and gas stretching some 40,000 miles from the comet’s body.
Scientists are hopeful the comet, which is believed to be making its first pass into the inner solar system, may put on a spectacular show for Earthlings between November and January 2014 after it comes as close as about 1.1 million miles to the sun.
Comet ISON, which was discovered in September by two amateur astronomers using the International Scientific Optical Network (ISON) near Kislovodsk, Russia, was imaged by NASA’s Deep Impact spacecraft in January. The 36-hour observation shows the dim but distinct point of light moving against a sea of bright background stars.
Comet ISON is not Deep Impact’s first experience with a comet. The spacecraft, which was launched in January 2005, released a small metal probe to impact the heart of Comet Tempel 1 in July 2005, then flew by for close-up studies.
Five years later and re-purposed for a new mission, it soared past Comet Hartley 2. Deep Impact is now on its way to a January 2020 visit to an asteroid.
Image: Deep Impact’s view of Comet ISON. Credit: NASA/JPL-Caltech