With so many large asteroids making the headlines lately, it would be easy for a smaller one to slip the careful monitoring of various space agencies. In fact, one almost managed to do it. On April 27th, astronomers have spotted a new asteroid, a small piece of space rock between four and eight meters (13 to 26 feet) in diameter.
The asteroid was already close to Earth by the time it was discovered, and the probability of a clash was determined to be about ten percent. At its size, it would have completely exploded when faced with the atmosphere of our planet, so it posed no threat to us anyway.
The Flyby Was a Good Thing, Actually
However, the asteroid’s trajectory would carry it close to the geostationary ring, the area of space around Earth in which cosmic bodies can keep geostationary orbit. That area is filled with satellites.
On April 28th, the asteroid, called 2020 HS7, flew past our planet at a distance of 42,735 kilometers (26,554 miles), which is approximately nine times closer than the distance of the Moon. The Earth to Moon distance is 384,400 kilometers (238,855 miles) from the center to the center on average, but 2020 HS7 managed to execute one of the closest asteroid flybys ever registered.
It also passed by the nearest satellite by only 1,200 kilometers (746 miles), which might sound concerning, but neither the planet nor the satellites were in any danger.
“Small asteroids like 2020 HS7 safely pass by Earth a few times per month,” said astronomer Lindley Johnson of NASA‘s Planetary Defense Coordination Office just prior to the flyby. “It poses no threat to our planet.”
According to researchers, asteroid 2020 HS7 was actually a good thing, as it allowed them to test their detection, observation, follow-up, and prediction abilities on a small near-Earth space rock. They did demonstrate that they could predict and monitor the trajectory of asteroid 2020 HS7 with impressive accuracy, even with only a day’s notice.
Other near-Earth asteroids have made it to headlines in the last few months, with larger space rocks such as 2020 BX12 and 1998 OR2 – the latter of which having its close approach just a day after 2020 HS7 – swing past Earth.
Astronomers have also tracked comet 2l/Borisov, the interstellar space rock, fragment into dust. However, even though it may seem like there are more cosmic objects than ever in our vicinity, experts are getting really good at detecting and monitoring them.
This is good news because it means we are becoming better geared to manage an asteroid that could pose a threat to our planet. Detection, observation, and prediction are only the first steps in dealing with this matter.
What comes after that is still figured out, but we see progress. In 2022, space agencies around the globe will be collaborating to crash a spacecraft into an asteroid that’s not coming towards Earth, in order to see if they are able to divert its trajectory.
If the plan works, we’ll have another instrument in the tool kit for keeping large space rocks far from our planet.