500th comet found by SOHO
NASA-GSFC NEWS RELEASE
Posted: August 14, 2002

  Comet
Photo: NASA/ESA
 
Amateur astronomers worldwide placed their bets, crossed their fingers and waited in anticipation for the ESA-NASA Solar & Heliospheric Observatory (SOHO) spacecraft to spot its 500th comet. Their patience was rewarded on August 12 as SOHO, a mission actually designed to research the Sun, revealed its own type of royal flush with comet C/2002 P3 (SOHO).

It is the 500th comet to be discovered by SOHO since it launched on December 2, 1995, making the spacecraft by far the most prolific comet-hunting observatory in history.

Between May 2 and May 31, using the SOHO website, 1,256 amateur astronomers tracked SOHO's observations of comets and made predictions about the date and time that the 500th comet would be at perihelion (the closest approach to the Sun). Comet C/2002 P3 (SOHO) had a perihelion time of August 12 at 12:04:48 p.m. EST.

Diane McElhiney won the sweepstakes with a prediction only one hour and 43 minutes away from the correct time.

The website also allows comet aficionados around the world to look at real-time SOHO data and images. Once they see what appears to be a new comet, they seek confirmation from others on-line. If confirmation is provided, they have accomplished a feat that is the goal of many amateur astronomers.

More than 75 percent of the comet discoveries have come from amateurs from Australia, Canada, China, France, Germany, Italy, Lithuania, Russia, the United Kingdom and the United States.

"Analyzing SOHO data is a great challenge and you have to combine many skills," said Rainer Kracht, the discoverer of C/2002 P3 (SOHO). "But every amateur astronomer dreams of finding a comet."

Kracht, a mathematics, physics, computer science and astronomy teacher at the Kooperative Gesamtschule Elmshorn in Elmshorn, Germany, has discovered 63 comets since August 2001 with the help of SOHO data and images. An entire group of near Sun comets that he discovered is even named after him - the Kracht group.

C/2002 P3 (SOHO) is not only an unanticipated milestone for the mission, but whereas most near Sun comets are of the Kreutz family, C/2002 P3 (SOHO) is a member of a family of comets called the Meyer group. The Meyer group is one of three new families that have been discovered with SOHO data. A comet family is a group of comets that originated from the same place and follow the same path. C/2002 P3 (SOHO) has a perihelion distance of 5.37 million km from the Sun.

"We don't yet know much about this family, or the other new families," said Dr. Doug Biesecker, the head of SOHO's comet discovery program stationed at NASA's Goddard Space Flight Center and a solar physicist with L3 Com Analytics Corporation. "With such few known members of this family, we need every additional comet we can get."

The use of SOHO as a tool to discover comets is a byproduct of the mission's original purpose - to continuously monitor solar weather and assist scientists in analyzing how the Sun functions. The Large Angle and Spectrometric Coronagraph (LASCO), one of the instruments on SOHO, blocks out the Sun to create an artificial eclipse and then views the space around the Sun, looking for outbursts of solar activity. This eclipse allows the Sun's faint outer atmosphere (corona) to be seen and studied.

Like the corona, comets that would usually be lost in the glare of the Sun unexpectedly come into LASCO's field of view. Almost all of them end up vaporized in the solar atmosphere. In spite of the fact that the SOHO Kreutz family comets tend to be only 10 meters in diameter, they are fragments of a comet that was originally much larger, maybe 100 km in diameter. This is so large, in fact, that it might have been visible during daylight more than 2000 years ago.

"Though LASCO was not originally built for this purpose, no other instrument has discovered more of these comets," said Dr. Bernhard Fleck, ESA Project Scientist for SOHO stationed at Goddard. "It was a wonderful surprise, of the kind we get in science sometimes."

Hubble
Astronomy Now presents Hubble: the space telescope's view of the cosmos. A collection of the best images from the world’s premier space observatory.
 U.S. STORE
 U.K. & WORLDWIDE STORE
Apollo 15 DVD - offer ends soon
For a limited time only, preorder your Apollo 15 DVDs at a special discount price. Two- and six-disc editions of this unique DVD are coming soon.
 U.S. STORE
 U.K. & WORLDWIDE STORE

ERROR: Random File Unopenable

ERROR: Random File Unopenable

The random file, as specified in the $random_file perl variable was unopenable.

The file was not found on your file system. This means that it has either not been created or the path you have specified in $trrandom_file is incorrect.
STS-134 Patch

Free shipping to U.S. addresses!

The final planned flight of space shuttle Endeavour is symbolized in the official embroidered crew patch for STS-134. Available in our store!
 U.S. STORE
 WORLDWIDE STORE

Final Shuttle Mission Patch

Free shipping to U.S. addresses!

The crew emblem for the final space shuttle mission is now available in our store. Get this piece of history!
 U.S. STORE
 WORLDWIDE STORE

Apollo Collage
This beautiful one piece set features the Apollo program emblem surrounded by the individual mission logos.
 U.S. STORE

STS-133 Patch

Free shipping to U.S. addresses!

The final planned flight of space shuttle Discovery is symbolized in the official embroidered crew patch for STS-133. Available in our store!
 U.S. STORE
 WORLDWIDE STORE

Anniversary Shuttle Patch

Free shipping to U.S. addresses!

This embroidered patch commemorates the 30th anniversary of the Space Shuttle Program. The design features the space shuttle Columbia's historic maiden flight of April 12, 1981.
 U.S. STORE
 WORLDWIDE STORE

Mercury anniversary

Free shipping to U.S. addresses!


Celebrate the 50th anniversary of Alan Shephard's historic Mercury mission with this collectors' item, the official commemorative embroidered patch.
 U.S. STORE
 WORLDWIDE STORE

Apollo 11 special patch
Special collectors' patch marking the 35th anniversary of the historic Apollo 11 moon landing is now available.
 Choose your store:
U.S. - U.K.

Gemini 7
Gemini 7: The NASA Mission Reports covers this 14-day mission by Borman and Lovell as they demonstrated some of the more essential facts of space flight. Includes CD-ROM.
 Choose your store:
U.S. - U.K. - E.U. - Worldwide

Apollo patches
The Apollo Patch Collection: Includes all 12 Apollo mission patches plus the Apollo Program Patch. Save over 20% off the Individual price.
 Choose your store:
U.S. - U.K. - E.U. - Worldwide

Mars Rover mission patch
A mission patch featuring NASA's Mars Exploration Rover is available from our online.
 Choose your store:
U.S. - U.K. - E.U. - Worldwide

Apollo 9 DVD
On the road to the moon, the mission of Apollo 9 stands as an important gateway in experience and procedures. This 2-DVD collection presents the crucial mission on the voyage to the moon.
 Choose your store:
U.S. - U.K. - E.U. - Worldwide

Station Calendar
NEW! This beautiful 12" by 12" wall calendar features stunning images of the International Space Station and of the people, equipment, and space craft associated with it, as it takes shape day by day in orbit high above the Earth.
 U.S. STORE
 U.K. & WORLDWIDE STORE

Get e-mail updates
Sign up for our NewsAlert service and have the latest news in astronomy and space e-mailed direct to your desktop (privacy note: your e-mail address will not be used for any other purpose).

Enter your e-mail address:

INDEX | PLUS | NEWS ARCHIVE | LAUNCH SCHEDULE
ASTRONOMY NOW | STORE

ADVERTISE

© 2014 Spaceflight Now Inc.