The asteroid 2023 NT1 was first spotted on July 15, two days after it made its closest approach to Earth on July 13. In other words, by the time telescopes and scientists were first made aware of the rock’s existence, we were already in its rearview mirror.

This asteroid was hard to see earlier because it approached the Earth from the direction of the sun, the star’s glare blinded our telescopes to the asteroid’s approach until long after it had passed 

After calculating the asteroid’s trajectory for the next decade astronomers say asteroid 2023 NT1 didn’t pose any danger to Earth. But it was an important reminder that truly dangerous asteroids could fly towards Earth – and that we might not spot them until they are too late as the sun remains a well-known blind spot in the search for near-Earth asteroids.

In 2013, a roughly 59-foot-long (18 m) asteroid followed a similar path through the sun’s glare and went undetected before exploding in the sky over Chelyabinsk, Russia. The explosion released a shock wave that damaged buildings and shattered glass for miles around, ultimately injuring nearly 1,500 people.

The European Space Agency estimates there could be a million asteroids in the same size range of 30 to 100 metres near Earth. And 98.9% of them are still undiscovered, the space agency says.

While scientists closely monitor more than 31,000 known near-Earth asteroids, they are well aware of the dangers posed by the solar blind spot.

To address this threat, the European Space Agency is hard at work on the NEOMIR mission. The satellite, scheduled to launch around 2030, will orbit between Earth and the sun in an effort to detect large asteroids hidden in our star’s shine.

Updated: 20 Jul 2023, 06:32 PM IST