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With Less Than a Day’s Notice, Unistellar Network Tracks Down Near-Earth Asteroid

With Less Than a Day’s Notice, Unistellar Network Tracks Down Near-Earth Asteroid

2019 XS Orbit frame

On November 8, 2021, Unistellar sent out an urgent message to our global network of citizen astronomers. A small asteroid would be passing very near to Earth in less than 24 hours, and we wanted to catch it in action. Luckily, not one but three of our Unistellar Ambassadors rose to the challenge, finding and observing asteroid 2019 XS as it flew by at 3 a.m. UTC the next day.

The school-bus-sized Near-Earth Asteroid was first found in 2019 by the Mount Lemmon Survey in Arizona, part of Planetary Defense observations that seek out asteroids that come close to our planet.


Though small, 2019 XS comes close to Earth about once a year, even crossing our planet’s orbit. That makes it potentially dangerous.

Astronomers, including those at the SETI Institute our scientific partner, are keeping an eye on the asteroid, and one of their best looks came earlier this month, when 2019 XS passed within about 570,000 kilometers (350,000 miles) of Earth, or about 1.5 times the distance to the Moon. Thanks to an assist from the Unistellar Network, it t was a chance to not only observe the asteroid, but also to confirm astronomers’ calculations of its orbit.

With less than a day’s notice, three Unistellar Ambassadors set up their eVscopes and spotted the tiny asteroid as it rocketed past. Tateki Goto of Japan, Scott Kardel of the United States and Pierre-Michael Micaletti of France all gathered important citizen science data on 2019 XS, helping astronomers better understand how this Earth-crossing asteroid is moving through the solar system.

Citizen Scientist Tateki Goto
Citizen Scientist Scott Kardel
Citizen Scientist


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