2 IIT-Bombay students in team that identified asteroid that flew past Earth

The SUV-sized asteroid, which zoomed past around 2,950km above the Earth’s surface on Sunday, was identified by an international collaboration that comprises two students from the Indian Institute of Technology-Bombay (IIT-B). Named ‘2020 QG’, it is the closest known asteroid to fly by the planet without impacting it.

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The students, Kunal Deshmukh and Kritti Sharma, who are part of a collaboration searching Near Earth Asteroids, identified this object just hours after it passed by Earth, using data from the robotic Zwicky Transient Facility (ZTF) in California.

While analysing ZTF data, the two reported five streaks as “potential asteroids”, unknown to the fact that one of it was the record-breaking asteroid. “The data looked like all other near-earth asteroids we have seen so far,” said Deshmukh, a final-year student in the department of Metallurgy and Materials Science at IIT-B.

“Helping make a discovery like this, so early in my research project, is beyond what I had ever imagined,” said Sharma, third year student of mechanical engineering.

The students reported their findings to the International Astronomical Union Minor Planet Center, after which several global telescopes followed up to learn more about the asteroid’s size and orbit.

“We at IIT-Bombay are ratified by the Center and study the data recorded by ZTF, California. So when the students reported the discovery to the Center, the same had to be verified by other independent observers too,” said Varun Bhalerao, assistant professor, department of physics, IIT-B, and an advisor to the students.

The feat has now been verified by observers.

“The asteroid flew so close to the planet that earth’s gravity significantly changed its orbit,” says ZTF co-investigator Tom Prince, the Ira S Bowen Professor of Physics at Caltech and a senior research scientist at JPL, which Caltech manages for NASA. Asteroids of this size that fly roughly as close to earth as 2020 QG do occur about once a year or less, but many of them are never detected, he said.

According to a release on the official website of Caltech, each night, machine-learning programs automatically sort through about 100,000 images in search of these streaks, and then narrow down the best asteroid candidates to be followed up by humans. This results in about 1,000 images that team members and students sort through by eye every day.

“Asteroid 2020 QG was identified by Kunal Deshmukh, a student at the Indian Institute of Technology-Bombay. Deshmukh had been scanning that day’s images along with Kritti Sharma, also at the Indian Institute of Technology-Bombay, and Chen-Yen Hsu at National Central University in Taiwan,” the release said.

Arvind Paranjpye, director of Nehru Planetarium, called it a “very important discovery because it was so close to earth that the planet’s gravity could perturb its course”. “We need more such discoveries of inter-planetary missiles and this discovery is a matter of pride for the country,” he said.

Asteroid 2020 QG is about 10 to 20 feet (3 to 6 metres) across, or roughly the size of an SUV, so it was not big enough to do any damage even if it had been pointed at Earth; instead, it would have burned up in the planet’s atmosphere. The previous known record of an asteroid that flew this close to the planet was in 2011. The asteroid, 2011 CQ1, discovered by the Catalina Sky Survey, was around 2,500km higher than 2020 QG.

“We are very excited about our next phase: studying such objects with the robotic GROWTH-India Telescope at Hanle, Ladakh,” Bhalerao said.

GROWTH-India is a partnership between the Indian Institute of Astrophysics, Bengaluru, and IIT-B, with support from the Indo-US Science and Technology Forum (IUSSTF) and the Science and Engineering Research Board (SERB) of the Department of Science and Technology (DST). It is a part of the international GROWTH collaboration.