Despite a few previous claims of breaking up or fizzling out (which, technically, was a misquote anyway — it was ‘fizzing’ not ‘fizzling’) it appears that the incoming comet ISON is holding together just fine… although how well it does as it swings closely around the Sun in November has yet to be seen. While it’s not very bright to the naked eye in the night sky yet, ISON is looking pretty good in this new image from Hubble!
A new image of the sunward plunging Comet ISON suggests that the comet is intact despite some predictions that the fragile icy nucleus might disintegrate as the Sun warms it. The comet will pass closest to the Sun (aka perihelion) on November 28.
In this NASA Hubble Space Telescope image taken on October 9, the comet’s solid nucleus is unresolved because it is so small. If the nucleus broke apart then Hubble would have likely seen evidence for multiple fragments.
Moreover, the coma or head surrounding the comet’s nucleus is symmetric and smooth. This would probably not be the case if clusters of smaller fragments were flying along. A polar jet of dust first seen in Hubble images taken in April is no longer visible and may have turned off.
Want to know how to observe ISON? Check out this article by David Dickinson.
This color composite image was assembled using two filters. The comet’s coma appears cyan, a greenish-blue color due to gas, while the tail is reddish due to dust streaming off the nucleus. The tail forms as dust particles are pushed away from the nucleus by the pressure of sunlight. The comet was inside Mars’ orbit and 177 million miles from Earth when photographed. Comet ISON is predicted to make its closest approach to Earth on December 26, at a distance of 39.9 million miles.
By the way, there’s no need to worry about comet ISON. It’s not going to hit Earth, or Mars, or have any effect on our planet whatsoever. (And no, it’s not “Nibiru.”)
(Oh, and welcome back, NASA! 🙂 )