Closest Asteroid to Pass Earth for a Year Will Fly by Thursday After Being Discovered 4 Days Ago

An asteroid that was discovered just four days ago will make an "extremely close"—albeit safe—approach to our planet this Thursday, astronomer Gianluca Masi from the Virtual Telescope Project told Newsweek.

At around 7:18 a.m. ET on September 24, the object—known as 2020 SW—will come within around 16,700 miles of Earth, which is less than one tenth of the average distance between our planet and the moon, according to NASA's Center for Near Earth Object Studies.

In astronomical terms, that is a tiny distance. In fact, CNEOS figures show that over the course of the next 365 days, 2020 SW will come likely come closer to our planet than any other near-Earth object (NEO) that we currently know about.

Near-Earth objects are any asteroids or comets with a predicted trajectory that takes them within 121 million miles of our star, or 30 million miles of the Earth's own orbital path.

The 2020 SW object is a relatively small asteroid, estimated to measure between around 14 and 32 feet in diameter. When it flies past our planet it will be travelling at a staggering speed of more than 17,300 miles per hour, which is over eight times faster than a rifle bullet.

The object was discovered by the Mount Lemmon astronomical survey—operated from an observatory in the Santa Catalina mountains northeast of Tucson, Arizona—on September 18, 2020, and was officially described the following day the International Astronomical Union's Minor Planet Center.

Stock image: Artist's rendering of an asteroid. iStock

Despite being discovered only days ago, astronomical observations of this object have already shown that it is not on course to collide with Earth. And even if it did, the asteroid's small size mean it would likely burn up in the Earth's atmosphere.

"If an object this size were headed directly towards the Earth, it would disintegrate in the atmosphere, almost completely into dust but likely also with a shower of small meteorites," CNEOS director Paul Chodas told Newsweek.

"Asteroids are only detectable when then get sufficiently bright. [They] only get sufficiently bright when they get sufficiently close. Tiny asteroids like this one only get bright enough one, two or three days before close approach, depending on how fast they approach. Larger asteroids can be detected much farther away, and would likely have been discovered a month or more before the close approach, and possibly much earlier depending on the orbit."

If you would like to observe this space rock as it zooms past our planet, the Virtual Telescope Project will be tracking it live using its advanced, remotely-operated telescopes in Italy.

The live stream will begin at 6 p.m. ET on September and can be found here.

In total, astronomers know about roughly 25,000 near-Earth asteroids, of which more than 9,000 are estimated to measure greater than 460 feet in diameter.

Any near-Earth object with an estimate diameter of more than 460 feet that is predicted to come within around 4.6 million miles of our planet in future is designated as "potentially hazardous." There are currently thought to be around 5,000 of these objects, that will fly past Earth within this distance during the next two centuries.

This article was updated to include additional comments from Paul Chodas.