spaceSpace and PhysicsspaceAstronomy

A 5-Kilometer-Wide Asteroid Will Fly Past Earth This Weekend


Tom Hale


Tom Hale

Senior Journalist

Tom is a writer in London with a Master's degree in Journalism whose editorial work covers anything from health and the environment to technology and archaeology.

Senior Journalist

An artist's impression of Phaethon. NASA/JPL-CALTECH

Get ready, Earthlings. There's a 5-kilometer (3 miles) wide space rock about to zip past our planet this weekend.

Asteroid 3200 Phaethon will make its closest approach on Saturday December 16 at 5:30 pm EST (click here to convert that to your time zone). Unfortunately, you won’t be able to see the asteroid with the naked eye. However, even a backyard telescope should be able to pick it up with a bit of know-how. If you’ve got a computerized telescope, you catch a glimpse of it by aiming between HIP2113 and a magnitude 9 star, according to NASA Earth Sky.


Phaethon is the third largest near-Earth asteroid classified as a "Potentially Hazardous Asteroid" but there’s no need to worry about it. The rock will skim past Earth from a distance of 10.3 million kilometers (6.4 million miles) away. That’s around 27 times the distance between the Earth and Moon, so pay no heed to the headlines telling you it’s threatening Armageddon just before Christmas.

Even so, this is still pretty close in space-terms. It is the closest encounter with this asteroid since 1974 and until 2093, meaning it’s a prime opportunity for astronomists to study this flying space rock.

"This will be the best opportunity to date for radar observations of this asteroid and we hope to obtain detailed images," said NASA.

"The images should be excellent for obtaining a detailed 3D model."


If – with extra stress on the totally hypothetical "if" –  the asteroid did hit our planet, or any planet for that matter, Boston University astronomy professor Michael Mendillo told TIME that 3200 Phaethon would be a likely candidate. It "would be this type of object that would cause a catastrophic collision, should there be one," he said. 

Phaethon, only discovered in 1983, is named after the son of the Greek sun god Helios due to its close approach to our Sun. If you were lucky enough to witness the Geminid meteor shower earlier this week, these shooting stars actually came from debris left by 3200 Phaethon. That’s why this asteroid is sometimes referred to as "the mother of all Geminids."

Asteroids don’t typically behave like this, so some astronomers argue it is not actually an asteroid at all but, in fact, a dead comet or perhaps just a comet that’s breaking apart.


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