Prime time for comet view­ing near

Connecticut Post (Sunday) - - News - Con­tact Robert Miller at earth­mat­ter­srgm@ gmail. com By Robert Miller

“Comets are like cats. They have tails and they do pre­cisely what they want.’’ — Astronomer David Levy

An­other ce­les­tial tabby is about to prom­e­nade past us. With luck, it will purr and rub against our an­kles, rather than turn tail with barely a nod our way.

Comet 46P/ Wir­ta­nen is about to get very close to Earth in De­cem­ber — only 7.2 mil­lion miles away. It will be the 10th clos­est comet pass in mod­ern times.

If it bright­ens enough — as many as­tronomers ex­pect it to do — peo­ple may be able to see it with their naked eyes, mak­ing it the bright­est comet of the past few years.

“Let’s put it this way,” said Richard Tal­cott, se­nior ed­i­tor of As­tron­omy Mag­a­zine. “As comets go, this should be a pretty good one.”

Which has put area as­tronomers on alert.

“We haven’t seen it yet,” said Monty Rob­son of the John. J. Mc­Carthy Ob­ser­va­tory at New Mil­ford High School. “But we’ll be look­ing for it. It’s within our range.”

And be­cause Comet Wir­ta­nen will be most vis­i­ble, high in the sky, near the Pleiades in the mid­dle of De­cem­ber, it will co­in­cide with the Gem­i­nid me­teor shower — tra­di­tion­ally one of the best of the year.

Which means, if the night skies are clear, there will rea­sons for se­ri­ous sky­watch­ing par­ties.

Rob­son said the Mc­Carthy Ob­ser­va­tory will al­most cer­tainly have a pub­lic event in mid- De­cem­ber.

New Pond Farm in Red­ding, in con­junc­tion with The Dis­cov­ery Cen­ter in Ridge­field, al­ready has a date set — Dec. 15 at 6: 30 p. m. To reg­is­ter, go to the Dis­cov­ery Cen­ter’s web­site at ridge­field­dis­cov­ery. org or New Pond’s at new­pond­farm. org

“All in all, it should be a pretty good night,” said Cliff Wat­t­ley of Ridge­field, who leads the sky­watch events at New Pond Farm.

Comets are ei­ther dirty snow­balls or snowy dirt­balls that or­bit around our so­lar sys­tem. When those or­bits take them close to the sun, some of their mass melts, with the de­bris flow­ing be­hind cre­at­ing their tails. When that de­bris hits the Earth’s at­mos­phere, we see it as a shoot­ing star.

There are bil­lions, even tril­lions, of comets in the Oort Cloud and Kuiper Belt at the outer edge of the So­lar Sys­tem. Hu­mans — who have been watch­ing them for mil­len­nia, first in fear, then sci­en­tif­i­cally — have iden­ti­fied 5,253 of them.

Astronomer Carl Wir­ta­nen first iden­ti­fied the comet named af­ter him in 1948 at the Lick Ob­ser­va­tory in San Jose, Calif.

Un­like some far­away vis­i­tors, Comet 46P/ Wir­ta­nen is part of the neigh­bor­hood. Its or­bit takes it around Jupiter and back, cir­cling the sun every 5.4 years. It’s also rel­a­tively small, with a di­am­e­ter of three- quar­ters of a mile.

What makes it spe­cial this year is sim­ply that its or­bit is bring­ing it closer to Earth than it usu­ally does. As it gets closer to the sun, it should brighten enough to see eas­ily with binoc­u­lars or a tele­scope.

Brighten some more, and it be­comes a naked- eye ob­ject — a fuzzy cot­ton ball of light amid the star’s sharper points.

Tal­cott, of As­tron­omy Mag­a­zine, said what also makes Comet Wir­ta­nen good for or­di­nary sky­watch­ers is that it will be ac­ces­si­ble. Peo­ple can view it around 9: 30 to 10 p. m. rather than at 3 a. m. Rather than hang­ing low near the hori­zon, it will be high in the sky.

What as­tronomers don’t know is whether Wir­ta­nen will show off or be a noshow.

“It’s any­body’s guess,” said Ge­off Ch­ester, spokesman for the U. S. Naval Ob­ser­va­tory in Wash­ing­ton.

Ch­ester said 1973’ s Comet Ka­houtek was the most cel­e­brated ce­les­tial dud of re­cent years.

“It was billed as the comet of the cen­tury,” Ch­ester said. “It was more like the comet of the month.”

On the other hand, in 2007 Comet Holmes flared much brighter than any es­ti­ma­tion. And two re­cent comets — Hyaku­take in 1996 and Hale- Bopp in 1997 — lived up to their ad­vanced no­tices and were breath­tak­ing.

The Gem­i­nids — which peaks Dec. 12- 14 — is the prod­uct of de­bris the ob­ject known as 3200 Phaethon leaves as it or­bits through the so­lar sys­tem.

Phaethon was once clas­si­fied as a as­teroid. To­day as­tronomers think it might be some­thing com­pletely dif­fer­ent — a dor­mant comet, a rock comet.

“The Gem­i­nids are spe­cial,” Rob­son of the Mc­Carthy Ob­ser­va­tory in New Mil­ford said.

Com­bine them with a liv­ing comet and mid- De­cem­ber could a great night for look­ing at the heav­ens.

“It could be spec­tac­u­lar,” Rob­son said.

Matthew Fearn / As­so­ci­ated Press

Roger Bon­net, of the Euro­pean Space Agency, holds a model of the Rosetta space­craft.

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