ISON Image of the Week

ISS ISON  (Dec 09, 2013)

On November 23, 2013, a human floating above the Earth in a giant orbiting space station, took this photograph of comet C/2012 S1 (ISON). If the nature of this photo does not impress you, you're a tough audience! [Image credit: NASA]
We know by now that comet ISON is very likely gone but it is certainly is not forgotten, and over the coming couple of weeks we will continue to see a steady trickle of cool images come in. This latest photo of comet ISON is particularly exciting as not only was it taken by a hand-held camera... but it was taken from space!

This image was taken by one of the Russian crew members aboard the International Space Station (ISS) on November 23, 2013, using an 85mm lens and a 0.1sec exposure time, looking out the starboard side of the ISS. The star field isn't completely clear but the bright point to the left of ISON is Mercury.

While this clearly isn't one of the more spectacular photographs of ISON that we've seen, it's really very cool for a couple of reasons. The first reason is obvious: it was taken by a human being floating above Earth in a giant space station! (If that alone doesn't impress you, then you are a tough audience indeed.) But the second reason is that by November 23, when this image was taken, comet ISON was an extraordinarily difficult target to image, and for the most part it was only space-based observatories that were able to image the comet. By this time it was very close to the Sun, and terrestrial observers were finding the comet washed out by diffused sunlight in the dawn skies. But from the ISS, there's no atmosphere to get in the way, and there's a big planet that can be used to block out the Sun, so this lucky astronaut got to take full advantage of that!

We had hoped that by the time we posted our December 9, 2013 ISON Image of the Week, we would already have a bright comet ISON in the night skies. However, we never promised that would happen and sure enough it has not. In fact not only is comet ISON not bright, it's not visible at all, with astronomers reporting that searches down to magnitude +15 are returning negative results.

In the light (or lack thereof...) of the negative detections of comet ISON, one of the enduring mysteries now is exactly when the comet fell apart. We are very confident that the comet broke apart some time in the hours surrounding perihelion, but did it begin doing this days or weeks earlier? Was the November 24 outburst the result of fragmentation, or just a sungrazing comet doing what sungrazers do? It will take time to put ISON's pieces back together and figure out where it all went wrong for the comet, but we will certainly continue to add information to this website as new results are published. (At the end of this year, we may switch to an "ISON Image of the Month" for at least the first part of 2014.)

Every week this year we will put up a new image related to Comet C/2012 S1 (ISON). If you have a cool image you'd like us to consider, please send it to sungrazer@nrl.navy.mil, along with a description and any credits you would want applied. We'll contact you if we choose to use your image on the CIOC Website.

See our ISON Image of the Week Archives for earlier picks!