For months, the asteroid named “2021 QM1” was at the top of risk lists around the world. As far as we knew, there was a real possibility of the space rock impacting Earth on April 2, 2052. But after a series of scientifically impressive observations and calculations, the European Space Agency’s (ESA) asteroid team is working with experts at European Southern. The Observatory (ESO) has removed the asteroid from its risk list. These observations included analysis of the “weakest asteroid ever observed” with one of the most sensitive telescopes on the planet.
2021 QM1 was first discovered on August 28, 2021, by Mount Lemon Observatory in Tucson, Arizona. Initially, the discovery was nothing special as about a dozen new near-Earth asteroids are discovered every dark night. But the following routine observations from telescopes around the world began to tell a more worrying story.
“These early observations gave us more information about the asteroid’s path than we projected into the future. We could see its future path around the Sun, and it could have come dangerously close to Earth in 2052. The more asteroids observed, the greater the risk it became,” ESA’s chief of planetary defense, Richard Moisel, said in a press statement.
However, it should be noted that orbit calculations based on some nightly observations come with uncertainties. This is why asteroids are often added to ESA’s risk list soon after being discovered and subsequently removed. Once more data is gathered, the uncertainties are reduced and, generally, the asteroid proves to be safe. But this could not happen on this occasion.
As luck would have it, just as the asteroid’s risk was increasing, a cosmic alignment was in the works and stood in the way of observation: the asteroid’s path brought it as close to the Sun as seen from Earth, which meant months. It was impossible to see because of the glare of the sun.
“We just had to wait. But to kick things off, we knew that 2021 QM1 was also moving away from Earth in its current orbit – meaning by the time it exits the Sun’s glare, It may be too small to be detected,” explained astronomer Marco Micheli of ESA’s Near-Earth Object Coordination Center (NEOCC), in a press statement. But they were preparing as they waited.
ESO’s Very Large Telescope (VLT), located in the Atacama Desert in northern Chile, was primed and ready for observation. The VLT will focus its 8-meter mirror on the 50-meter asteroid as soon as it shoots out of sunlight as soon as weather conditions allow.
“We had a brief window into which our risky asteroid could be seen. To make matters worse, it was passing through a region of the sky just behind the Milky Way. “These will be some of the most difficult asteroid observations we’ve made,” Olivier Hainaut, an astronomer at ESO, said in a press statement.
On the night of 24 May, the VLT took a series of new images and once the data arrived, Olivier and Marco began processing them by stacking subsequent observations on top of each other and removing background stars in a time-consuming process. done. This has resulted in the positive detection of the weakest asteroid ever observed.
At the time of observation, 2021 QM1 was 250 million times dimmer than the faintest stars visible to the naked eye from a dark spot. Olivier was certain that this tiny speck was an asteroid. Marco could go a step further and confirm that given its location, this was the asteroid they were looking for.
These new observations were used to refine the predicted path of the risky asteroid, ruling out the impact in 2052, and 2021 QM1 was removed from ESA’s risk list, leaving only 1,377 other asteroids on the list. were given.
