It’s been a while since the Northern Hemisphere has experienced a good comet show. In fact, it has been 15 years since Hale-Bopp, the last “Great Comet” to be seen by starwatchers above the equator, sparked a trail across the night-time sky. But 2013 promises to double-up on not only comets that can be seen in the night-time sky, but on “Great Comets” as well. And the second comet just might be so spectacular, it could very well be the “comet of the century.”
According to Space.com, we’ll get a visit from Comet PANSTARRS, a comet that will pass within 102 million miles of the Earth at its closest. Discovered in June 2011 by scientists using the Pan-STARRS 1 Telescope (thus its name) at Haleakala, Hawaii, the comet is expected to etch the sky in mid-March, from the 10th to the 24th.
The second comet, also a “Great Comet,” is expected to show up next December. Discovered by amateur astronomers Vitali Nevski of Belarus and Artyom Novichonok of Russia, Comet ISON was named for the International Scientific Optical Network (using an acronym), the agency that owned the telescope the two men used in their discovery. Comet ISON is projected to come within 40 million miles of Earth a month after reaching its perihelion with the sun. That is, if it survives its perihelion run. Comet ISON is what is known as a “sungrazer.” It will get within three-quarters of a million miles of the sun on Thanksgiving Day, 2013. If the comet does survive its close passage, it is expected to be approximately 15 times more brilliant than the moon and linger in the skies for a month beginning in mid-November.
Astronomers believe that Comet ISON may be as brilliant as the Great Comet of 1680, a comet that has the distinction of being the first comet ever discovered with a telescope. That particular comet, also known as Kirch’s comet (after its discoverer, Gottfried Kirch), had an exceptionally long tail and reportedly was so bright as to be seen during the day.
“If Comet ISON can survive perihelion passage … then we are almost surely in for a striking display in the morning sky as Comet ISON recedes from the Sun next December,” comet researcher John Bortle noted earlier this month on the Comets Mailing List. “Its immense tail, partly the result of our extremely favorable viewing circumstances in this case and just as with the Great Comet of 1680, could well result in a tail of amazing length and surface brightness, even if tipped by only tiny, relatively insignificant head.”
“Great Comets” are distinguished from others by their magnitude of brightness. Although there is no true defining parameters of what constitutes a “Great” comet from more ordinary comets, it is generally agreed that the “Great” comets are readily noticeable via casual observance. They are also to be distinguished from an average comet that can be observed by the naked eye. As such, the “Great” ones are exceeding rare and appear about once a decade.
In that regard, both Comet PANSTARRS and Comet ISON should most definitely fit the description.
It should be pointed out that, even though major comets haven’t been seen in the northern hemisphere since 1997 (and in 1996, with Comet Hyakutake), there have been Great Comet observances in the southern hemisphere. According to the Alamogordo Daily News, stargazers south of the equator were entertained by Comet McNaught in 2007 and Comet Lovejoy in 2011.
Although astronomers amateur and professional see the double cometary year as a stroke of good fortune, comets historically have been viewed upon as omens of ill luck. And given that there are doomsayers saddened that the so-called Mayan prophecies didn’t pan out and doomsday prognosticators looking to 2013 for an end-time solar flare or super volcano eruption, the appearance of two Great Comets in the sky in the same year will undoubtedly be too much to pass up and will most likely get the apocalypse drums going again.
For the rest of us, Comet PANSTARRS and Comet ISON should put on a pair of exceptionally beautiful light shows.