asteroid didymos didymoon
© European Space agencyAIM and Didymos binary
An asteroid as big as the Egyptian pyramids is zooming towards Earth and will squeeze past us on Friday - if it doesn't smash on to our home planet's surface. Named 2019 WR3, NASA expects the space rock to make a "close approach" to Earth later this week.

The space agency has classified the asteroid as a "near-Earth object (NEO)" which means its orbit brings it very close - in cosmic terms - to Earth.

The asteroid was first spotted late last week.

NASA has now observed the asteroid some 74 times to better get a sense of its size and trajectory.


Comment: Oh boy, they were REALLY worried about this one.


WR3 is believed to have a diameter of between 76m to 170m. It is expected that on December 6, the asteroid will pass within 5.44 million km of Earth at speeds of 27,036 km/hr.

The warning comes as the European Space Agency approves a $471 million mission called Hera to examine whether a rogue asteroid on its way to Earth could be deflected out of the way. Working with NASA, the ESA will send a pair of spacecraft to a double-asteroid system called Didymos to examine the asteroids and send valuable data back home.


The larger asteroid Didymoon is about 800m across, orbited by a moon about 160m wide.

If an asteroid the size of Didymoon were to hammer into Earth, it would be devastating.

Patrick Michel, ESA's lead scientist for Hera, said it was vital to keep an eye on it so we can take action if needed.

"The probability is low but the consequences are high," Michel told Space.com.

"This is why it's relevant to take care of it. Moreover, we have the tools ... We can't lose more time."

The Hera spacecraft will launch in 2024.


Meanwhile, Queens University Belfast professor Alan Fitzsimmons has called for amateur astronomers to assist the Hera mission's broader goal of protecting Earth against asteroids by nominating asteroids to watch.

"We will get a serious asteroid impact sometime," he told the BBC.

"It may not be in our lifetime, but mother nature controls when that will happen.

"We will need to do something about it. We'll need to move that asteroid so it misses us and doesn't hit us.

"Asteroid research is one area of astronomy where amateur observes continue to make an essential contribution," he said.