In the year 2017, an interstellar space object spurted across our solar system. It was named Oumuamua. It was the first time we had ever detected an interstellar object passing through the solar system and its unusual shape was evocative of the artificial vessel in Rendezvous with Rama science fiction novel by Arthur C. Clarke. Presently, a Ukrainian has found an object zooming through our solar system that has been confirmed as a comet — and this is something that the sun is unlikely to capture.
The comet, named C/2019 Q4 (Borisov), was caught on the night of September 9-10 by the Gemini North Telescope’s Gemini Multi-Object Spectrograph. The picture manifested a very articulated tail indicating outgassing and confirming that the object is a comet. This is another first, with C/2019 Q4 being the first interstellar visitor to form a tail due to outgassing.
Comet C/2019 Q4 (Borisov) is likely our second interstellar visitor after Oumuamua. Gennady Borisov found it. The coma can already be detected by scientists— the blurred ice and dust trail that spins off the comet as it approaches the sun and starts to melt. And contrary to’ Oumuamua, Q4 is still approaching Earth. While it will not be nearer than 180 million miles, until December 7 it will not achieve that point. We have more time to watch this ancient visitor, and there are hopes that from the coma of debris it sheds we can detect hints about its origin. We didn’t identify Oumuamua until it was out of our solar system already, but C/2019 Q4 (Borisov) was picked up previously.
“This is the first highly active object that we’ve seen coming in from something that formed around another star,” Michele Bannister, an astronomer at Queen’s University Belfast, explained to National Geographic.
Andrew Stephens, an astronomer who works with the Gemini Observatory, was responsible for coordinating the observations. As he remarked:
“This image was possible because of Gemini’s ability to rapidly adjust observations and observe objects like this, which have very short windows of visibility. However, we had to scramble for this one since we got the final details at 3:00 am and were observing it by 4:45!”
Comets such as C/2019 Q4 aren’t notable— at any given moment there are an estimated 10,000 bits of interstellar debris in orbit between here and Neptune. But this material is small and highly hard to observe. It is much more unusual to identify parts of incoming interstellar objects. We don’t have comprehensive comet pictures yet because the present core is so tiny in diameter ranging from 1.2 to 10 miles. It should be noticeable through April 2020 with mid-powered telescopes, but after that date only with professional telescopes will be observed. C/2019 Q4 is supposed to disappear from perspective by October 2020 — assuming, of course, it’s not something entirely different.