Amateur astronomer spots potentially dangerous asteroid just days before it flies past Earth

An amateur astronomer spotted a potentially dangerous asteroid heading towards Earth just days before it flew past us.

The object would have created global devastation if it smashed into Earth. But it flew past at a safe distance, at a range of 40 million kilometres or more than 100 times the distance between the Earth and the moon.

Still, experts have noted that it is a reminder that relatively large objects could easily be missed as they approach Earth, and repeated warnings that without large-scale tracking the planet could be at risk from unexpected collisions.

The object – officially known as Asteroid 2020 QU6 – was first spotted by Leonardo Amaral at the Campo dos Amarais observatory in Brazil, on 27 August. It made its closest flyby past Earth on 10 September.

There are a host of advanced surveys intended to spot such objects before they get so close. But experts said that the discovery is a reminder that those systems are not entirely reliable, and there could be many other interesting – and potentially dangerous – objects flying around waiting to be found.

“This discovery reminds us that even though we’ve found most large NEOs [Near-Earth Objects], we haven’t found all of them,” said Casey Dreier, chief advocate and senior space policy adviser for The Planetary Society, in a statement.

“We must continue to support ground-based astronomers and invest in new space-based capabilities like NEOSM [Near-Earth Objects Surveillance Mission] in order to protect Earth now and in the future.”

Nasa has been tasked by the US Congress to find and track 90 per cent of near-Earth objects that are 140 metres or bigger by 2020. But it has struggled to do so, amid appeals for more funding: it has only found 40 per cent of those objects, and isn't expected to get to its target for another 30 years.

The Planetary Society noted that most major asteroid-hunting projects are based in the northern hemisphere, meaning that the world is more at risk of missing those that approach from south of the equator. As such, projects such as those from Mr Amaral are key to spotting asteroids that might otherwise go missed.

The object is just the latest asteroid to fly past Earth after having being spotted relatively late on its approach. Such detections cause concern because they suggest that dangerous asteroids could arrive without detection – but the discovery should be cause for hope rather than concern, said one expert.

“In the news, we hear more and more frequently about asteroid discoveries primarily because we are getting better at finding and tracking near-Earth asteroids,” said Planetary Society Chief Scientist Bruce Betts in a statement. “There aren’t suddenly more asteroids, we’re just getting better at seeing them.”