Credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA)
For eons, Comet ISON has drifted in the cold, far reaches of our solar system’s Oort Cloud. We don’t yet know ISON’s fate, but we do know this: the comet’s long sleep is over.
When first imaged by Hubble on April 10, ISON was only just inside the orbit of Jupiter. Even then, the Sun was warming ISON’s surface, causing a coma of gas to form as ice sublimates – transitions directly from a solid to a gas. Researchers hope the changes ISON was undergoing this spring will shed light on what the comet has in store for stargazers this fall.
This early image doesn’t appear to show much. The Hubble filter we used lets in light across the visible spectrum, not in specific colors – the blue and white in this image just show how the comet’s overall brightness falls off as you get farther away from the nucleus. With clever analysis, though, this image can speak volumes.
The same ISON image, minus a computer model of what a simple cometary coma might look like.
The above image is tricky. It’s not what Hubble saw. Instead, it’s a ...