Image Credit: SOHO/ESA/NASA/NRL
Prior to the 1995 launch of the observatory, commonly known as SOHO, a joint project of the European Space Agency and NASA, only a dozen or so comets had ever even been discovered from space, while some 900 had been discovered from the ground.
The dot in the cross-hairs is a comet streaming toward the sun, as seen on Sept. 14, 2015, by the ESA/NASA Solar and Heliospheric Observatory. This is the 3,000th comet discovered in the data from that space telescope since it launched in 1995. The comet was originally spotted by by Worachate Boonplod of Samut Songkhram, Thailand. Credits: ESA/NASA/SOHO
SOHO’s mission is to observe the sun and interplanetary space, above Earth’s atmosphere that blocks so much of the sun’s radiation. From there, SOHO 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.
In this video, Karl Battams of the Naval Research Lab talks us through a visualization of the comets that SOHO has witnessed.
SOHO and comet-finding infographic. Credits: NASA’s Goddard Space Flight Center/Duberstein