A car-sized asteroid just made the closest-known approach to Earth without actually colliding with the planet. And researchers didn't even know about it until hours after it had already passed.
Asteroid 2020 QG, formerly known as ZTFoDxQ, zoomed past Earth on Sunday at 12:08 a.m. EDT, getting as close as 1,830 miles away. It marks the closest asteroid flyby ever recorded in which the object actually survived.
For compassion, the International Space Station is 254 miles away.
"Near-Earth Asteroids (NEAs) pass by Earth all the time, but 2020 QG passed closer to Earth than any other known NEA without actually impacting," a NASA spokesperson told CBS News on Tuesday.
According to the International Astronomical Union's Minor Planet Center, 2020 QG was first observed at the Palomar Observatory several hours after it passed over the southern Indian Ocean.
Orbit diagram shows asteroid 2020 QG as it passes by Earth on August 16, 2020.
NASA JPL
Not only was the approach extremely close, it was also super fast. The asteroid was traveling at a whopping 27,600 miles per hour, or about 7.7 miles per second.
Being only about 10 to 20 feet in diameter, the asteroid was not actually big enough to pose a serious threat. If it had been on a collision course, it would have likely ended up as a fireball — an extremely bright meteor — as it broke up in Earth's atmosphere.
The asteroid "approached Earth from the direction of the Sun and was not discovered until after it passed and could be observed in the night sky by ground-based observatories," NASA confirmed.
NASA carefully tracks near-Earth objects, but it's only aware of a fraction of them due to such observational limitations.
Scientists at NASA are developing a telescope that could detect asteroids coming from the direction of the sun, eliminating the current blind spot in their observations. The Near-Earth Object Surveillance Mission could launch as early as 2025.
NASA is also planning to launch the Double Asteroid Redirection Test (DART) in July 2021. DART will purposely crash into a harmless asteroid moon in the fall of 2022 to attempt to change its motion, in the first test for planetary defense.