Cumberland Times-News

March 2, 2013

Comet to appear low in mid-March skies

Bob Doyle, Columnist
Cumberland Times-News

— Twenty months ago, a powerful automated telescope in Hawaii discovered a faint comet as far as the giant planets are from the sun.

The comet is called PAN STARRS for the Panoramic Survey Telescope And Rapid Response System that discovered it. This 70-inch mirror telescope is devoted to a continuing search for asteroids and comets that may come close to the Earth.

This comet’s orbit is close to a parabola so it is likely that this is the comet’s first visit to the inner solar system.

There is a possibility that this comet may become a conspicuous object once it is heated by the sun at its closest approach on March 10. Comet PAN STARRS will then be closer to the sun than Mercury.

Close encounters of comets by space probes have found that comet cores are usually dark, except for fissures in their surfaces where powerful streams of water vapor and other gases erupt.

These gases give a comet an atmosphere called the coma (Latin for “hair”) that is the brightest part of a comet. The coma for some comets have been bigger than the planet Jupiter. The much smaller solid part of the comet is called the nucleus, a dark space iceberg several miles across.

PAN STARRS is now visible in southern hemisphere skies. From a close study of its brightening, predictions are that PAN STARRS should be visible low in our western dusk using binoculars starting on March 12.

The sun will then be setting about 7:20 p.m. (Daylight Time will then be in effect). Forty-five minutes after sunset is the best time to see the comet. So a little after 8 p.m. observe from a place with a very flat western horizon.

Weather permitting, you will be able to spot a slender crescent moon. Then to the left and above the moon will be Comet PAN STARRS. You will likely see the comet as a “furry star.” Its tail, if visible will be pointing away from the sun.

On the following nights the comet will shift farther to the right while the moon will climb well above the comet.

On March 16, the Cumberland Astronomy Club will be setting up telescopes on the North end of the Glendening Recreational Complex In Frostburg to observe PAN STARRS, the crescent moon and the planet Jupiter.

You are advised to arrive at early dusk (7:30 to 7:45 p.m.) so you can spot the telescopes set up in a parking area just off the end of the road. This telescope viewing session can only take place if it’s clear.

There should be an even brighter comet seen in our December skies. Comet ISON was discovered by two Russian astronomers who are part of the International Scientific Optical Network.

Just as PAN STARRS, this comet is named after the network that found it. ISON differs from PAN STARRS as this comet is a sun grazer, a comet that will pass within a million miles of the sun’s surface.

ISON seems to be big enough so that it will likely survive this close passage of the sun. Some smaller sun grazers have come apart due to the tidal forces and extreme heating by the sun.

On Nov. 28, Ison will make its closest approach to the sun. It will then rapidly move away from the sun and become visible in our dusk skies in December.

It is possible that comet ISON may be a very bright object with an easily seen tail. The comet’s path will take it into our northern sky and near the North Star. Comet Ison may then be seen all through the night hours.

In March, I give a half-hour talk with accompanying visuals on the Hooved Animals of Northern Plains each Sunday at 4 p.m. (except Easter Sunday, March 31). After the talk, visitors are welcome to tour our wonderful collection of preserved mammals from five different continents.

These talks are held in the Science Discovery Center, just off the first-floor entrance of the Compton Science Center. Close by our first floor entrance is the construction site for the CCIT building, now more than half completed.

The CCIT building will have a multi-media auditorium with a digital planetarium projection system. In early 2014, our Sunday planetarium programs for the public will resume.

SKY SIGHTS AHEAD: The moon is now rising after midnight; it will appear half full in the southern dawn skies on Tuesday. Orion and the bright stars around it are now seen in the southwestern evening skies.

To the right of Orion is the bright planet Jupiter. The ringed planet Saturn can be seen before midnight low in the East. The best telescopic views of Saturn’s rings will be at dawn when the planet is well up in the southern sky.

Bob Doyle invites any readers comments and questions. E-mail him at rdoyle@frostburg.edu . He is available as a speaker on his column topics.