Have you heard the news about Comet ISON (“IceOn”)? It is still too early for real precise estimates, but we could be in for the biggest comet show of the century. As you can imagine, there is lots of excitement among professional and amateur astronomers as well as us casual observers. The ghost of Comet Kohoutek seems to be tempering the excitement this time around however.
Comets are mixtures of ice, rock, and dust. They are often described as dirty snowballs a few miles in diameter, but snowy dirtballs might be a more accurate description. When comets pass near the sun, the heat causes the comet to shed ice and particles. This is when a coma and tail may form which becomes visible from the earth.
Comet ISON (C/2012 S1) was discovered September 21 of last year by a couple of Russian astronomers. At that time the comet was 584 million miles from the sun or 625 million miles from earth cruising through space at 425,000 mph. Recent estimates are that it is between 2/3 – 4 miles across. There is a real possibility that this comet will surpass the brightness of Comet Hale-Bopp back in 1997 and Comet McNaught in 2007. Some estimates have it becoming 15 times brighter than a full moon by the end of the month, which would make it visible even during the daytime.
The comet is expected to peak in visibility on around Thanksgiving Day. Actually it will be on November 28 at 2:10 pm Central Time. That is when it will go streaking through space at a mere 800,000 miles from the sun. That is perihelion or its closest position to the sun. So if the sky is clear, it could be great viewing before dawn on Thanksgiving Day and then again after sundown.
The big question is whether the comet will stay intact or break up as it approaches the sun and all that heat. If it breaks up, there will not be much to see. However, if it stays intact, and some astronomers think that it will because of its size, we could be in for perhaps the celestial treat of a lifetime. Watch and listen for the news on Comet ISON over the next few weeks.
Natural North Dakota is supported by NDSU Central Grasslands Research Extension Center and Minot State University-Bottineau, and by the members of Prairie Public. Thanks to Sunny 101.9 in Bottineau for their recording services.