Why report an asteroid that has no chance of beating the earth? Since this asteroid, known as the 2006 QV89, has a history. A story that is difficult to trace.
As the name says, this asteroid was discovered in 2006. It is an Asteroid near the Earth (NEA, or NEO, too close to Earth objects.) An object is classified as an NEO when its perihelion, or nearest approach to the sun, is within 1, 3 astronomical units. And if there is a path crossing the Earth's orbit, and the object is greater than 140 meters above, it is called a potentially dangerous object (PHO.)
2006 QV89 is about 30 meters in diameter, so it is too small to do enough damage to be a PHO. But we did not always know that QV89 was not dangerous.
QV89 was difficult to trace first, just like many asteroids. One appears in the sky, scientists have a short time window to limit their size and their orbit, then in a few days it may be gone. And it can't be visible again for decades. Based on the short observation window, astronomers must determine whether it is a risk or not, and whether to put it on the risk list. (All that the risk list means is that the items on it have a non-zero chance of beating list. Not so good, really.)
When QV89 was first discovered, it was only visible for 1
Astronomers wanted to track this asteroid, but they didn't know where to look. If it sounds like an insurmountable problem, it is not. What scientists know is where QV89 would have to be in heaven, it would hit the earth. This means that even if we do not see this matter, we can exclude an influence.
On July 4th and 5th, ESO and ESA astronomers were used with the Very Large Telescope (VLT) to search for the night sky. Instead of trying in vain for the small rock, they pointed to the massive telescope where the asteroid would be, if it was heading towards us. The effort is part of the ongoing cooperation between ESA and ESO to follow high-risk asteroids. The VLT, with its 8.2 meter primary mirror, has the power to see asteroids moving through space, if you know where to point it.
They didn't see anything. They took a very deep picture of Heaven's area where 2006 QV89 would have to be if it were to extinguish our planet in September, and it wasn't there.
The above is a picture of the sky region where the asteroid 2006 QV89 would be, only if it was on a collision course with the earth in 2019. The image was taken with the very large telescope (VLT) of the European Southern Observatory. The segment shown by the three red crosses in this image shows where the asteroid would be if it was on a collision course. It has been processed to remove the background star contamination, so if it was in the picture, the asteroid 2006 QV89 would appear as a single light round light source within the segment.
Although the asteroid was smaller than astronomers believe, maybe just a few feet above, it would pop up. Anything less than that and the VLT would not have seen it. But it was so, when 2006 QV89 would also be harmless. Everything as small would simply burn up in the earth's atmosphere.
So we're safe. Until further notice. There is officially a zero percent chance that it will hit the ground, and ESA has taken 2006 QV89 off its risk list. We can never hear about it again.