12 June 2024 - Mission Day: 10421 - DOY: 164

The SOHO 2000th Comet Contest

Comets SOHO-999 and

Comets SOHO-999 and

Comets SOHO-999 and SOHO-1000, detected in 2005 (Movie).

Even though SOHO's primary target is the Sun, its onboard LASCO instrument has become the most prolific comet discoverer in history! LASCO is a coronagraph package with nested fields of view. Since LASCO began observations in January 1996, the C2 and C3 coronagraphs have observed over 1800 comets. The majority of these comets belong to the Kreutz group of sungrazing comets.

To celebrate this outstanding achievement, we invite you to ENTER THE COMPETITION to predict the perihelion of the 2000th SOHO comet - and win a prize!



As many of our readers know, SOHO held a 2,000th comet contest to see who could come closest to guessing when the 2000 comet would reach perihelion (closest approach to the Sun). The three closest guesses will be sent some nice solar-related prizes. Comet perihelion time was Dec. 27, 2010 at 0800UT.

And our winners were:

  • Erik Olson of Carpinteria, CA had said it would be 13:36UT that day.
  • Naoto Tatsumi, Okayama, Japan guessed 23:59UT that day.
  • Bill Rankinen of Conneaut, OH guessed Dec. 24 at 18:34UT.

Congratulations to the winners and thanks to all who participated in the contest!


Related Links


• European Site • US Site


Feedback & Comments: SOHO Webmaster

Last modification: July 27, 2020

SOHO is a project of international cooperation between