Comet ISON, discovered in September of last year by Russian Vitali Nevski, is headed in our direction. And although the sungrazing comet is still more than 394 million miles away (a little closer than Jupiter's current orbit), NASA's Hubble telescope managed to capture an amazing photograph on April 10.
NASA believes that when ISON is at its closest point to the sun on November 28 of this year, it will briefly become brighter than the moon in the sky, making it a serious contender for "comet of the century."
Currently, the comet is headed toward the sun at a speed of around 47,000 miles per hour and has a dusty head of around 3,100 miles wide (about 1.2 times the width of Australia). Its tail trails more than 57,000 miles behind. And yet, the core of the comet's head is tiny -- no more than around 3 to 4 miles across.
This, according to researchers, is surprisingly small considering the comet's level of activity. Already, the comet is reacting to the heat of the sun at its current distance, sublimating ice and creating a dust jet of sublimated ice and frozen gases that extends 2,300 miles in front of the comet.
When ISON reaches its perihelion, or closest point to the sun, of just over 700,000 miles, it's expected that its icy nucleus, intensely heated by the sun's rays, will sublimate not just ice and gas, but also silicates and even metals, burning brighter than the moon.
"As a first-time visitor to the inner solar system, Comet C/ISON provides astronomers a rare opportunity to study a fresh comet preserved since the formation of the solar system," said Planetary Science Institute Research Scientist Jian-Yang Li, who led a team that imaged the comet. "The expected high brightness of the comet as it nears the sun allows for many important measurements that are impossible for most other fresh comets."
(Source: Crave Australia)