Space telescope discovers 5000th comet (which is special, because it was not designed for that)

The SOHO space telescope of the Sungrazer Project has now spotted its 5000th comet. The news marks an important (and somewhat unexpected) milestone for both NASA and ESA.

A solar binoculars that later turned out to be a real comet hunter; that is now the story of the Solar and Heliospheric Observatory (SOHO) space telescope. As the name suggests, SOHO was originally intended primarily to monitor the sun and the surrounding area, better known as the ‘corona’ of the sun. SOHO’s images are publicly available, and it is perhaps not surprising that many space enthusiasts enjoyed studying these (unique) images carefully. This quickly led to so many discoveries of comets venturing near the sun that collaborating scientists from NASA and ESA decided to set up an official program where these comets could be reported: The Sungrazer Project. This project has now achieved an important milestone: the discovery of SOHO-5000. The website of The Sungrazer Project able to here to be found. SOHO’s images can here to be found.

Then more about the comet itself; SOHO-5000. This turns out to be a relatively small celestial body that mainly consists of ice and rock. The comet does not fly by by chance, but appears to have been in the area for some time. For example, scientists suspect that the comet is part of the Marsden-group; a collection of comets probably related to comet 96P/Machholz. In that sense, SOHO-5000 is quite unique: of the 5000 comets, only about 75 comets are part of the Marsden-group.

Credit: ESA/NASA

Space fan
The comet was spotted by Hanjie Tan. Tan is a real fan of space; he has been participating since he was 13 The Sungrazer Project and is currently studying astronomy in Prague. He says: “I took part in the project in 2009. Since then I have discovered more than 200 comets. I love spotting comets; it is incredibly exciting to be the first to spot a comet. Especially because these comets often glow when they approach the sun.” Tan is one of the youngest participants in the project.

There is a good reason why the SOHO space telescope is able to observe so many comets. For example, this space telescope uses a physical disk to block direct light from the Sun, so that the area around the Sun can be studied. However, this turned out to have another unexpected advantage: by blocking sunlight, SOHO can suddenly spot comets much better that would otherwise have remained invisible.

The milestone is significant because achieving it shows how important projects such as The Sungrazer Project are. Scientist Karl Battams leads the project. He explains: “(in 1995, ed.) Before the SOHO mission started, we had only identified a small number of comets. The fact that we have now managed to capture more than 5,000 comets is astonishing. Together, these comets provide a super unique dataset that is very valuable for science. Achieving this milestone was only possible because so many volunteers participate in the project. Together they devoted many hours to the project.”