[meteorite-list] SOHO Spots Its 1000th Comet

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Thu Aug 18 11:14:30 2005
Message-ID: <200508181513.j7IFDHU01862_at_zagami.jpl.nasa.gov>

http://space.com/scienceastronomy/050817_comet_hunter.html

All-time Best Comet-Hunter Spots Number 1000
By Bjorn Carey and Robert Roy Britt
space.com
17 August, 2005

The best comet hunter in history recently spotted its 1,000th comet,
accounting for nearly half the comets ever discovered.

The Solar and Heliospheric Observatory (SOHO), which is run by NASA and
the European Space Agency, was designed to watch the Sun, but has since
proved to have excellent ability at spotting comets.

The images SOHO took were posted to the internet and amateur
sky-watchers had the opportunity to find and report new comets. Amateurs
were finding comets so quickly that SOHO operators decided to make a
contest of it, awarding a prize to the person who discovered the 1,000th
comet.

Italian high school teacher Toni Scarmato got lucky on Aug. 5 and
spotted comets numbers 999 and 1,000 in the same SOHO image.

"I am very happy for this special experience that is possible thanks to
the SOHO satellite and NASA-EVA collaboration," Scarmato said. "I want
to dedicate the SOHO 1000th comet to my wife Rosy and my son Kevin to
compensate for the time that I have taken from them to search for SOHO
comets."

For his accomplishment, Scarmato will receive a SolarMax DVD, a SOHO
T-shirt, solar viewing glasses, and more.

A second SOHO comet-spotting contest awarded prizes to Andrew Dolgopolov
of Ireland for the closest guess - within 22 minutes - of when the
1,000th comet would be spotted.

The SOHO spacecraft was engineered to watch solar eruptions
and the ensuing space weather that sometimes bombards Earth.

But early on in the mission, armchair astronomers figured out they could
become comet discoverers using SOHO
images posted to the Web. Because SOHO is trained on the Sun, it only
sees comets that whiz by the Sun, called Sun grazers.

Sun grazers are often hard to spot because they are lost in the glare
from the overwhelming light produced by the Sun. But SOHO is equipped
with a device that blocks light from the Sun's main disk so detailed
images can be made of the solar atmosphere and surrounding space.

"Before SOHO was launched, only 16 sun grazing comets had been
discovered by space observatories," said Chris St. Cyr, senior project
scientist for NASA's 'Living With a Star' program at the agency's
Goddard Space Flight Center. "Based on that experience, who could have
predicted SOHO would discover more than 60 times that number, and in
only nine years."

Some 85 percent of all SOHO comets belong to the Kreutz group, named
because their orbits take them within 500,000 miles of the Sun's visible
surface. Some make a trip around the Sun and head back out to the far
reaches of the solar system on wildly elongated orbits. Others don't
make it, being gravitationally drawn right into the star
on close approach.

Other comets discovered without SOHO, such as one named Kudo-Fujikawa,
have at times been watched in real time by web surfers
as they dramatically sliced across SOHO's field of view. In 2003, a
comet named NEAT, whose path in front of the SOHO cameras was well
predicted, was smacked by a solar storm, the first
such event ever recorded.

SOHO is a joint effort between NASA and the European Space Agency. It
has accounted for about half of all comet discoveries, through history,
in which orbits have been calculated.

A timeline for milestone comets spotted by SOHO (comet number and date
spotted):

100: Feb. 4, 2000
200: Aug. 31, 2000
300: Mar. 25, 2001
400: Feb. 26, 2002
500: Aug. 14, 2002
600: Apr. 29, 2003
700: Dec. 2, 2003
800: June 11, 2004
900: Jan. 15, 2005
1000: Aug. 5, 2005
Received on Thu 18 Aug 2005 11:13:17 AM PDT