A citizen scientist has helped the space telescope SOHO discover its 3,000th comet, nearly 20 years after it was launched by NASA and the European Space Agency to observe the Sun.
The 3,000th comet was originally spotted in the data by Worachate Boonplod from Thailand.
“I am very happy to be part of a great milestone for SOHO’s comet project,” said Boonplod.
Prior to the 1995 launch of the observatory, only a dozen or so comets had ever even been discovered from space, while some 900 had been discovered from the ground.
The Solar and Heliospheric Observatory (SOHO)’s mission is to observe the Sun and interplanetary space, from where it watches the solar disk itself and its surrounding environment, tracking the constant outward flow of particles known as the solar wind, as well as giant explosions of escaping gas called coronal mass ejections, or CMEs.
In its two decades in orbit, SOHO has opened up a new era of solar observations, dramatically extending our understanding of the star we live with.
With its clear view of the Sun’s surroundings, SOHO can easily spot a special kind of comet called a sungrazer, because of its close approach to the sun.
“SOHO has a view of about 12-and-a-half million miles beyond the Sun,” said Joe Gurman, mission scientist for SOHO at NASA’s Goddard Space Flight Centre US.
“So we expected it might from time to time see a bright comet near the Sun. But nobody dreamed we’d approach 200 a year,” Gurman said.
SOHO’s great success as a comet finder is dependent on the people who sift through its data – a task open to the world as the data is publicly available online in near-real time.
A cadre of volunteer amateur astronomers dedicate themselves to searching the data via the NASA-funded Sungrazer Project.
While scientists often search SOHO imagery for very specific events, various members of the astronomy community choose to comb through all the imagery in fine detail.
As a result 95 per cent of SOHO comets have been found by these citizen scientists.
“The people who have found comets represent a very broad cross section as the programme is open to anyone who has interest,” said Karl Battams, a solar scientist at the Naval Research Laboratory in Washington, DC.
More than just a celebrated bright vision in the night sky, comets can tell scientists a great deal about the place and time where they originated.