Nasa says asteroid could collide with Earth on Valentine's Day 2046

Object named 2023 DW was first detected by scientists on February 27

Asteroid 2023 DW is estimated to be about 50 metres in diameter. Photo: Nasa

US space agency Nasa says it is tracking an asteroid that could collide with Earth in 2046 — possibly making impact on Valentine's Day.

The asteroid 2023 DW is expected to make a very close approach to Earth on February 14, 2046, with the European Space Agency predicting a 1-in-625 chance of a direct hit.

Nasa said the celestial body has a "very small chance" of hitting our planet.

The object was first detected on February 27, according to the European Space Agency. It is estimated to be about 50 metres in diameter.

The odds of impact are expected to reduce after several more weeks of data are collated on the asteroid.

"We've been tracking a new asteroid named 2023 DW that has a very small chance of impacting Earth in 2046," Nasa wrote on Twitter.

"Often when new objects are first discovered, it takes several weeks of data to reduce the uncertainties and adequately predict their orbits years into the future.

"Orbit analysts will continue to monitor asteroid 2023 DW and update predictions as more data comes in."

Livescience.com reported that a direct impact from 2023 DW "would not be cataclysmic" like the 12-kilometre asteroid that hit Earth 66 million years ago, killing the dinosaurs, although it could cause "severe damage" if it were to land close to a major city or heavily populated area.

A rock less than half its size exploded over Russia in 2013, generating a shock wave that damaged thousands of buildings and injured hundreds of people, it said.

Last week, Nasa said it successfully knocked an asteroid off a potential collision course with Earth using a 544kg spacecraft that was travelling at more than 20,000kph.

The Double Asteroid Redirection Test (Dart) was conducted on September 26, but only now do scientists know the asteroid’s trajectory was altered.

“All of us have a responsibility to protect our home planet,” said Nasa administrator Bill Nelson at the time. "After all, it’s the only one we have.”