When an asteroid is discovered to have even a remote possibility of slamming into our planet, highly-detailed measurements are understandably necessary.
"Even if the asteroid were smaller than expected, at only a few metres across, it would have been seen in the image", ESA says. Such "astrometric: data improve our understanding of the asteroid's trajectory and refine the risk the space rock poses".
Scientists spotted 2006 QV89 in 2006, watched it for 10 days, and then couldn't find it again. Still, as we'll explain in a minute, the boffins persisted in their search because 2006 QV89 is a fairly worrying size.More news: Ohio Lawmakers Approve CBD, Hemp Legalization Bill
2019 NJ2 is joining the list of the last asteroids treading closely to Earth, namely 2006 QV89, 2016 NO56M, RF12 with 2019 NN3, 2019 MB4, 2019 MT2 in the same week. And nothing at all was seen in that region: so, no asteroid in that area means no real chance of it hitting our planet.
Regardless there is an ingenious method of getting the information needed.
As in the short observation period astronomers had not been able to calculate its orbit with accuracy, they settled on calculating the points in the sky where it would appear in the event that their predictions proved true and it was supposed to hit our home planet. "Therefore, we can simply observe this small area of the sky to check that the asteroid is indeed, hopefully, not there".More news: China's experimental space lab Tiangong-2 to re-enter earth's atmosphere
However, they didn't give up: by simulating the orbital mechanics of 2006 QV89, they identified the area of space the asteroid would have to travel through if it was to have a serious chance of hitting Earth.
In order to confirm whether or not the asteroid was still headed for collision with Earth, astronomers at the European Space Agency (ESA) and ESO took a different approach.
Now, follow-up observations have brought out the result that none of the asteroids we know about are at risk of impacting the Earth.More news: It Chapter Two's New Trailer Will Give You Nightmares
Three red crosses reveal the specific locations, where the asteroid could have appeared as a single, bright, round source, had it been on a collision course.