Asteroid 2020 RF3 was only discovered a matter of days before it swung past Earth. The unexpected asteroid came within a quarter of a distance between the Earth and the Moon – making it the 61st asteroid to do so this year – but thankfully passed us without a threat.
The asteroid passed at a safe distance of 92,000 kilometres, and while that may seem like a healthy distance, in astronomical terms that is nothing.
For reference, the closest planet to Earth, Venus, reaches 38 million kilometres at its closest point.
Asteroid RF3 is a relatively small space rock. NASA estimates the asteroid measures anywehere between 5.3 and 12 metres.
This would mean it would burn up in the Earth’s atmosphere if it came too close to our planet.
Asteroid pictures: Astronomers snap image of ‘EXTREMELY’ close encounter
Asteroid 2020 RF3 was 92,000 kilometres away
But despite its size, astronomers managed to take a picture of it against a backdrop of stars, describing it as an “extremely close approach”.
The Virtual Telescope Project, which photographed the space rock, said: “The near-Earth asteroid 2020 RF3 had an extremely close, but safe, approach with our planet, reaching a minimum distance from the Earth of about 92000 km, 0.24 times the average distance of the Moon.
“We managed to capture it a few hours before.
“At the imaging time, asteroid 2020 RF3 was at about 400000 km from the Earth, basically the lunar distance, and it was still safely approaching us.
What is a close approach?
“It was quickly moving South and it was already relatively low on our Italian sky. It was discovered by the Panstarrs survey on September 12 2020.”
Asteroid RF3 is part of a group of space rocks known as an Aten.
Aten asteroids, of which there are more than 1,000 typically have a close orbit to Earth, but pose no threat.
NASA has said the asteroid was a Near Earth Object (NEO), which means the space agency can study it as well as unravel secrets of the solar system.
Asteroids approaching Earth
NASA said: “NEOs are comets and asteroids that have been nudged by the gravitational attraction of nearby planets into orbits that allow them to enter the Earth’s neighbourhood.
“The scientific interest in comets and asteroids is due largely to their status as the relatively unchanged remnant debris from the solar system formation process some 4.6 billion years ago.
“The giant outer planets (Jupiter, Saturn, Uranus, and Neptune) formed from an agglomeration of billions of comets and the left over bits and pieces from this formation process are the comets we see today.
“Likewise, today’s asteroids are the bits and pieces left over from the initial agglomeration of the inner planets that include Mercury, Venus, Earth, and Mars.”