'Comet of the Century' Speeds to Earth: New Hubble Image of ISON
Comet ISON, dubbed the "comet of the century," is rapidly approaching Earth. With its spectacular tail trailing dust and particles, this comet is expected to shine bright in the sky come November. Yet NASA is getting an early look at ISON; the agency has used the Hubble Space Telescope to observe the comet as it streaks across space.
ISON is a comet, which means that it's made up of a combination of ice, frozen dust and gas. As it nears the sun, it trails debris in its wake; this creates the spectacular tail that you can see in Hubble's latest image. The newest image combines two Hubble filters. One filter lets in red light while the other lets in a greenish-yellow color. This allows for the spectacular colors that you can see in the backdrop of space behind the comet.
There's no guarantee that ISON really will be the comet of the century, though. How bright it is largely depends on evaporation rates and how quickly it sheds its dust and water. In April, researchers found that the comet was shedding about 112,000 pounds of dust and 130 pounds of water every minute. At the time, this meant that the water sublimation wasn't yet powering ISON's "jets" since it was still too far away from the sun.
Currently, researchers still aren't sure exactly how bright ISON will be. Yet the new image does show that it's continuing its steady trek toward the sun. In the picture, the comet appears fuzzier since the scientists kept the telescope trained on the background stars instead of following the comet. This gives the image the deep, rich background as photons from the Milky Way's stars and even more distant galaxies pile up over time in the same pixels.
While ISON's fate is uncertain, it's continuing to journey toward the sun. It's possible that the intensifying solar radiation from the peak of the sun's 11-year solar cycle could potentially help break the comet into pieces. Otherwise, though, ISON will put on a spectacular show in November. Train your eyes on the skies; we may be in for the comet of the century.