Three-Mile Wide Asteroid Will Zoom by Earth This December

But it will still be about 6.4 million miles away

Geminids streak across the skies above the Alabama Hills. The approaching asteroid is thought to be the parent body of this annual meteor shower. Henry Lee/Flickr CC

If you peek through a telescope on December 16, you might catch a glimpse of 3200 Phaethon, an asteroid that is projected to pass (relatively) close to Earth. It will be its nearest approach in 40 years, reports Alex Sundby of CBS News.

The space rock boasts a diameter of three miles, and it is expected to zoom by our planet from a distance of about 6.4 million miles—roughly 27 times the average distance between Earth and the moon. That is, admittedly, quite far away. But 3200 Phaethon has not been this close to Earth since December 16, 1974, when it passed us from a distance of around five million miles, according to NASA.

Because 3200 Phaethon crosses the Earth’s orbit, NASA has labeled it a “potentially hazardous asteroid.” Equally disconcerting is the fact that 3200 Phaeton is named after an ignominious figure in Greek mythology: the child of the sun god Helios, who crashes his father’s chariot into Earth and sets the planet ablaze. But the asteroid doesn’t pose any risk to us, Gareth Williams, an astrophysicist at the Harvard Smithsonian Center for Astrophysics, tells Ryan F. Mandelbaum of Gizmodo.

Scientists have modeled the asteroid’s path and determined that it “is not an object we need to worry about at this time,” Williams says. “Over tens of thousands of years the orbits will be perturbed by giant planets and the Earth, so the orbit could come closer.”

Though scientists know a fair bit about 3200 Phaethon’s trajectory, the asteroid remains mysterious. It is believed to be the parent body of the Geminids meteor shower, which sparkles in the sky each December. But meteor showers are typically associated with comets, not asteroids, leading some scientists to suggest that 3200 Phaethon could be an inactive comet nucleus, according to Sundby of CBS News. NASA has classified 3200 Phaethon as an “unusual object,” and scientists will be watching it closely when it passes by Earth next month.

The asteroid may also be visible through small telescopes, and the Virtual Telescope Project will be tracking it online. Anyone keen to see 3200 Phaethon should seize the opportunity in December. After its approach next month, Phaethon 3200 isn’t expected to pass near Earth again until 2093, when it will be about 1.85 million miles away.