[meteorite-list] Comet PANSTARRS Rises to the Occasion Mid-March

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Thu, 7 Mar 2013 16:23:25 -0800 (PST)
Message-ID: <201303080023.r280NPnb029517_at_zagami.jpl.nasa.gov>

http://www.jpl.nasa.gov/news/news.php?release=2013-088

Comet PANSTARRS Rises to the Occasion Mid-March
Jet Propulsion Laboratory
March 7, 2013

[Graphic]
For those in search of comet L4 PANSTARRS, look to the west after sunset
in early and mid-March. For those in search of comet L4 PANSTARRS, look
to the west after sunset in early and mid-March. This graphic shows the
comet's expected positions in the sky. Image credit: NASA
 -Larger image
<http://www.jpl.nasa.gov/images/asteroid/20130307/Panstarrs-Nasagraphic-640.jpg>

Comets visible to the naked eye are a rare delicacy in the celestial
smorgasbord of objects in the nighttime sky. Scientists estimate that
the opportunity to see one of these icy dirtballs advertising their
cosmic presence so brilliantly they can be seen without the aid of a
telescope or binoculars happens only once every five to 10 years. That
said, there may be two naked-eye comets available for your viewing
pleasure this year.

"You might have heard of a comet ISON, which may become a spectacular
naked-eye comet later this fall," said Amy Mainzer, the principal
investigator of NASA's NEOWISE mission at the Jet Propulsion Laboratory
in Pasadena, Calif., and self-described cosmic icy dirtball fan. "But if
you have the right conditions you don't have to wait for ISON. Within a
few days, comet PANSTARRS will be making its appearance in the skies of
the Northern Hemisphere just after twilight."

Discovered in June 2011, comet 2011 L4 (PANSTARRS) bears the name of the
telescopic survey that discovered it -- the less than mellifluous
sounding "Panoramic Survey Telescope and Rapid Response System" which
sits atop the Haleakala volcano in Hawaii.

Since its discovery a year-and-a-half ago, observing comet PANSTARRS has
been the exclusive dominion of comet aficionados in the Southern
Hemisphere, but that is about to change. As the comet continues its
well-understood and safe passage through the inner-solar system, its
celestial splendor will be lost to those in the Southern Hemisphere, but
found by those up north.

"There is a catch to viewing comet PANSTARRS," said Mainzer. "This one
is not that bright and is going to be low on the western horizon, so
you'll need a relatively unobstructed view to the southwest at twilight
and, of course, some good comet-watching weather."

Well, there is one more issue -- the time of day, or night, to view it.

"Look too early and the sky will be too bright," said Rachel Stevenson,
a NASA Postdoctoral Fellow at JPL. "Look too late, the comet will be too
low and obstructed by the horizon. This comet has a relatively small
window."

By March 8, comet PANSTARRS may be viewable for those with a totally
unobstructed view of the western horizon for about 15 minutes after
twilight. On March 10, it will make its closest approach to the sun
about 28 million miles (45 million kilometers) away. As it continues its
nightly trek across the sky, the comet may get lost in the sun's glare
but should return and be visible to the naked eye by March 12. As time
marches on in the month of March, the comet will begin to fade away
slowly, becoming difficult to view (even with binoculars or small
telescopes) by month's end. The comet will appear as a bright point of
light with its diffuse tail pointing nearly straight up from the horizon
like an exclamation point.

What, if any, attraction does seeing a relatively dim naked-eye comet
with the naked eye hold for someone who works with them every day, with
file after file of high-resolution imagery spilling out on her computer
workstation?

"You bet I'm going to go look at it!" said Mainzer. "Comet PanSTARRS may
be a little bit of a challenge to find without a pair of binoculars, but
there is something intimately satisfying to see it with your own two
eyes. If you have a good viewing spot and good weather, it will be like
the Sword of Gryffindor, it should present itself to anyone who is worthy."

NASA detects, tracks and characterizes asteroids and comets passing
relatively close to Earth using both ground- and space-based telescopes.
The Near-Earth Object Observations Program, commonly called
"Spaceguard," discovers these objects, characterizes a subset of them,
and predicts their paths to determine if any could be potentially
hazardous to our planet.

JPL manages the Near-Earth Object Program Office for NASA's Science
Mission Directorate in Washington, DC. JPL is a division of the
California Institute of Technology in Pasadena.

More information about asteroids and near-Earth objects is at:
http://www.jpl.nasa.gov/asteroidwatch , and on Twitter: _at_asteroidwatch .

DC Agle (818) 393-9011
Jet Propulsion Laboratory, Pasadena, Calif.
agle at jpl.nasa.gov

2013-088
Received on Thu 07 Mar 2013 07:23:25 PM PST