A 200-foot asteroid that missed Earth last week was not discovered until two days later

Briefly: If a huge asteroid were to hit Earth, would it be better not to know until the object lights up our sky? We found out about last week when a 200-foot-tall object passed our planet relatively close, something scientists only learned about two days later.

Astronomers at the Atlas Observatory in South Africa first detected 2023 NT1 on July 15, two days after it made its closest approach to Earth. The asteroid entered within a radius of 60,000 miles from the planet — about 1/4 the Moon’s distance to Earth.

newly discovered #asteroid 2023 NT1 passed about 1/4 the Moon’s distance on July 13, but wasn’t detected until July 15, when it approached Earth in the daytime sky. It may be up to 60 meters wide, and it may be larger than the asteroid that caused the meteorite crater in Arizona. pic.twitter.com/VLXB4ChTMJ

– Tony Dunn (@tony873004) July 16, 2023

We are usually aware of any potentially dangerous space objects long before they approach our planet. Asteroid 1994 XD, which has a diameter of between 1,214 and 2,723 feet, came within 1.96 million miles of Earth last month. It was discovered by the Spacewatch group at Kitt Peak Observatory in Arizona in 1994.

Asteroid 2023 NT1 was different, as it was traveling toward us from the sun and was therefore hidden by the star’s glare. This was the same reason no one spotted a 20-meter (65-foot) asteroid in 2013 until it exploded over the Russian city of Chelyabinsk in 2013, creating a shock wave that injured 1,500 people and damaged buildings.

NASA defines asteroids with dimensions of 2023 NT1 as being the size of an airplane. A quick look at the location of the ever-ominous Asteroid Launcher and the choice of New York as the point of impact shows that the object’s size and velocity (11.28 km per second) would leave a 225-meter (738-foot) crater. About 235 people will be vaporized and a 328-foot tsunami will be created. This is just an estimate: the asteroid that struck Arizona 50,000 years ago was slightly smaller than 2023 NT1 at 160 feet but made a Barringer crater 3,900 feet in diameter.

In an effort to avoid such future situations, the European Space Agency (ESA) has planned a project called Neumere. The mission will orbit between Earth and the sun around the first Lagrangian point (L1), giving the telescope a view of asteroids that may be coming towards Earth from the direction of the sun. Unfortunately, it is not scheduled to be released until 2030.

“By making observations in the infrared part of the light spectrum, Neumeire will detect heat radiating from the asteroids themselves, which are not drowned out by sunlight. This heat emission is absorbed by Earth’s atmosphere, but from space Neumeire will be able to see it much closer to the Sun than we can currently Earth,” writes the ESA.