On Sunday, August 16, at 12:08 a.m. EDT, an SUV-sized asteroid flew past our home planet. The asteroid set record for coming closer to the Earth than any other known asteroid that had flown by the planet, NASA says.
The previously known asteroid for making such record is 2011 CQ1. The Catalina Sky Survey discovered it in 2011 as it passed above Earth roughly 1,550 miles higher when compared to 2020 QG, according to NASA’s database of near-Earth objects.
Dubbed 2020 QG, the asteroid passed by 8 miles per second over the southern Indian Ocean without impacting the planet. Initially, it secured the identifier ZTF0DxQ before making an entry into the official catalog.
About 10 to 20 feet long, 2020 QG was unnoticed until six hours after passing by the Earth at its closest point. The rock was noticed by a California sky-scanning telescope that is funded by the National Science Foundation and NASA.
“It’s really cool to see a small asteroid come by this close because we can see the Earth’s gravity bend its trajectory,” said Paul Chodas, director of NASA’s Center for Near-Earth Object Studies.
By asteroid standards, the asteroid is very small. If it enters into the Earth’s atmosphere, it would likely have burned up into a fireball that happens many times a year.
“However, the rock flew close enough that the planet’s gravity significantly changed its orbit,” says ZTF (Zwicky Transient Facility) co-investigator Tom Prince. Such tiny asteroids fly equally close by the planet every year, but they often go undetected.
Paul Chodas at NASA’s Center for Near-Earth Object Studies said that it was pleasant to see a small asteroid passing by the Earth so close and seeing the Earth’s gravity bending its trajectory. Chodas added that based on their calculations, the rock turned by about 45 degrees as it flew by the Earth. He said it was an accomplishment to notice such tiny close-in asteroid as they pass by really fast. They have a very short window to notice and act before such tiny rocks become bright enough to be spotted by telescopes.
“ZTF’s rapid data processing and large-field of view allow the organization to record even the rarest asteroids that many other telescopes might not be able to spot,” says ZTF co-investigator George Helou.
ZTF is founded by the National Science Foundation (NSF) and is a NASA-funded program. It is an international collaboration of partners from all corners of the world. ZTF team members scan the northern sky every three nights for erupting stars, supernovas, and other cosmic objects that move or change in the sky.
These objects, including asteroids, speed across the sky, leaving behind streaks in the images captured by ZTF. Machine-learning programs automatically sort through millions of images, every night, to search for these streaks. As a result, these programs narrow down asteroid candidates, 1,000 images, which are followed up by humans.
Kunal Deshmukh, studying at Indian Institute of Technology Bombay, identified asteroid 2020 QG. He had been scanning the images for that day along with Chen-Yen Hsu at National Central University in Taiwan and Kritti Sharma at the Indian Institute of Technology Bombay.
When it comes to the orbit and classification, asteroid 2020 QG orbits the sun at an average distance of 1.0–2.9 AU in every 2.7 years. The eccentricity of the asteroid’s orbit is 0.49. It has an inclination of 5.5° with respect to the ecliptic. The close proximity with the Earth has reduced the asteroid’s orbital period to 964 days from 990 days.
As the 2020 QG asteroid has already passed by the Earth without causing any impact, it is considered not dangerous.
Telescopic observations suggest the object sized between a small car and an extended pickup truck. Even it is made of dense iron; only tiny pieces may have arrived at the ground.
As mentioned above, if the asteroid reaches the planet’s atmosphere, it would have burned out, detonating dozens of kilotons of TNT. It is equal to the atomic bombs dropped on Japan in 1945. Since the burst would have occurred nearly three miles above the ground, it would not have caused a sound louder than heavy traffic on the ground. This makes the discovery of the asteroid unnerving.
As asteroids coming from the direction of the sun are hard to record, NASA plans to address the issue with its advanced asteroid-hunting program. NASA is developing a space telescope capable of detecting comets and asteroids coming from the direction of the sun. If funding for the program continues, the telescope could become available as early as 2025.