This past weekend, an SUV-sized asteroid passed Earth in the closest flyby of its kind on record. Traveling at about 8 miles per second and measuring 10-20 feet, the small rock reached about 1800 miles above the Indian Ocean before returning to deep space.
NASA scientists did not discover the asteroid until it was already on an outgoing trajectory, which may sound worrying, but it is actually a common case. Asteroids near Earth are remarkably difficult to catch on a telescope, and most pass safely, though much farther away. In the case of this NEA, named 2020 QG, an impact would have resulted in an exceptionally bright meteor of which several occur each year.
“It’s quite an achievement to find these small asteroids nearby in the first place because they pass by so quickly,” said Paul Chodas, director of the Center for Near-Earth Object Studies (CNEOS) at Jet Propulsion NASA Laboratory in California. As a bonus, scientists were able to bend the Earth’s sciences’ path. “Our calculations show that this asteroid rotated 45 degrees as it swung across our planet,” Chodas said in a NASA announcement about the discovery.
NEA 2020 QG was first captured six hours after its closest approach to Earth, at 12:08 am EDT on Sunday, by the Zwicky Transient Facility, a sky-scanning survey telescope based at Caltech’s Palomar Observatory in San Diego County. The image of the asteroid appeared as a long line of light against an otherwise static and starry sky.
While the smallest asteroids near Earth do not pose a serious threat to Earth’s inhabitants, there is a slight difference between these small space rocks and their more dangerous relatives before detection is better performed. Objects measuring over 460 feet have a slower speed of movement over the air and are thus more easily captured by available instruments. NASA achieved a goal in 2005 to find 90% of NEAs in this larger size range.
Spaceon CEO Elon Musk has expressed his concern about Earth impact events on several occasions, and even cited it as a primary reason for humans to become a multiplanetary species. “Asteroid impact risk is well understood, but not cometic. They worry me, ‘he said recently wrote on Twitter. Remarkably, man still has the technology to not remove earth-bound space rocks – frozen or otherwise – from a disaster scenario. However, NASA and its international partners have a few missions in place with this issue in mind.
