Comet 73P/Schwassmann-Wachmann just missed us by 10 million kilometers last week. But this comet, which visits our Solar system every 5 years, is just a shadow of itself. Because of the powerful forces of the Sun, the comet broke into 3 parts in 1995. This year, it has almost completely exploded into 40 to 60 fragments depending on the observations. For its part, the European Space Agency (ESA) has used a superconducting camera to watch the fractured comet. This camera, known as SCAM, can count "almost every single photon of light that falls into it," allowing scientists to see into the interior of the comet -- maybe for the last time. But read more...
Here is what the ESA says about this SCAM camera.
The superconducting camera, SCAM, is an ultra fast photon counting camera, developed by ESA. It is cooled to just 300 thousandths of a degree above absolute zero. This enables its sensitive electronic detectors, known as superconducting tunnel detectors, to register almost every single photon of light that falls into it. As such, it is the perfect instrument with which to detect fast and faint changes in the fragments of the comet.
Below are images of comet 73P/Schwassmann-Wachmann taken on May 7, 2006 by SCAM. "It shows three of the new fragments produced by the splitting of the Fragment B -- one of the five original fragments into which the comet split in 1996. The spatial resolution of the images is about 70 km. (Credit: ESA)
[To take these images,] SCAM was attached to the one-metre ESA Optical Ground Station telescope on 7 May 2006, when the disintegrating comet was observed . Every few microseconds, the camera reads out the number of photons that have touched it and their colour. Using the unprecedented accuracy of the camera, ESA scientists charted the evolution of the dust and gas envelopes associated with each fragment for two hours.
Strangely, there are few details about this superconducting camera. One of the best sources about it is an ESA news release from January 2002. Below is a picture of the SCAM camera at this time, when it still was under development. (Credit: ESA)
The arrival of this comet in our neighborhood was widely covered by the media, so I have to choose between lots of pictures to illustrate this post. First, here is a beautiful X-ray picture of comet Schwassmann-Wachmann as it bypassed the Ring Nebula taken by NASA (Credit: NASA, via this article from Universe Today on May 16, 2006).
And remember that next time this comet comes around our Solar system, we might only see a meteor shower.
Sources: European Space Agency news release, May 19, 2006; and various web sites
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