2 small asteroids zip by Earth closer than the moon today

Two small asteroids will fly by Earth today (Oct. 19) at a range that's closer than the moon, a space rock double flyby that comes as NASA gears up for an asteroid encounter of its own.

The asteroids 2020 UX and 2020 TF6, both discovered in the last week, will be less than half the distance of Earth's moon (when they pass by today, but pose little threat to our planet. The moon, on average, is about 239,000 miles (385,000 kilometers) from Earth.

Asteroid 2020 UX was first spotted by astronomers on Oct. 15, according to NASA's Center for Near-Earth Object Studies at the Jet Propulsion Laboratory in Pasadena, California. It's about the size of a car (about 12 feet, or 4 meters, wide) and flew within 118,000 miles (190,000 km) of Earth when it made its closest approach early this morning.

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Asteroid 2020 TF6 was first spotted on Oct. 17. At about the size of a bus, it's a little bit larger than 2020 UX. It's about  60 feet (18 m) wide, according to CNEOS. It will be about 95,400 miles (153,500 km) at its closest approach. 

The double asteroid flyby comes as NASA counts down to its first-ever attempt to collect a sample from an asteroid. 

On Tuesday (Oct. 20), NASA's OSIRIS-REx spacecraft will attempt to "tag" the asteroid Bennu in the hopes of collecting samples of the space rock. It's NASA's first asteroid sampling attempt, although samples of a different asteroid were successfully returned to Earth by Japan's Hayabusa spacecraft in 2010. 

NASA launched OSIRIS-REx (its name is short for Origins, Spectral Interpretation, Resource Identification, Security-Regolith Explorer) in 2016 and the spacecraft arrived at Bennu two years later. Any samples of asteroid Bennu will be returned to Earth by the probe in 2023, NASA officials have said.

Asteroid flybys like today's are relatively common. Two more small asteroids will fly just inside the moon's orbit on Wednesday (Oct. 21).