Jul 20, 2023 12:30:00

A '20-story building-sized meteorite' approached Earth and passed closer than the Moon, but astronomers didn't notice it until two days later

It is not uncommon for asteroids to approach the earth, but astronomers constantly monitor asteroids approaching the earth because large asteroids can collide with the earth as meteorites, which can cause serious damage. doing. However, even though the 20-story, building-sized asteroid dubbed

2023 NT1 passed closer than the Moon to Earth on July 13, 2023, astronomers believe 2023 NT1 will pass. reportedly failed to notice the approach until two days after.

IAU Minor Planet Center
https://www.minorplanetcenter.net/db_search/show_object?object_id=2023+NT1

Airplane-sized asteroid found 2 days after brush by Earth
https://earthsky.org/space/asteroid-2023-nt1-close-call-earth-july-13-2023/

A skyscraper-size asteroid flew closer to Earth than the moon — and scientists didn't notice until 2 days later | Live Science
https://www.livescience.com/space/asteroids/a-skyscraper-size-asteroid-flew-closer-to-earth-than-the-moon-and-scientists-didnt-notice-until-2-days- later

On July 13, 2023, an asteroid with a width of about 60m called '2023 NT1' passed near the earth. The estimated speed of 2023 NT1 is 86,000 km / h, and it is said that it passed through a fairly close position, about a quarter of the distance from the earth to the moon.

You can see what kind of orbit 2023 NT1 passed near the earth by looking at the GIF video attached to the tweet below.

Newly-discovered #asteroid 2023 NT1 passed about 1/4 the Moon's distance on July 13, but wasn't discovered until July 15, as it approached Earth in the daytime sky. the asteroid that caused Meteor Crater in Arizona.pic.twitter.com/VLXB4ChTMJ

—Tony Dunn (@tony873004) July 16, 2023

The blue dot in the center is the Earth, and the yellow line is the orbit of 2023 NT1. Comparing it to the outer lunar orbit (white circle), you can see that 2023 NT1 passed fairly close to the Earth.

In 2013, more than 4,000

buildings were destroyed in Russia and about 1,500 people were injured. Even the meteorite that created Barringer Crater is believed to be about 50m in diameter. 2023 NT1 is larger than these famous meteorites.

2023 NT1 is not large enough to be considered a ' potentially dangerous asteroid ', and its orbital calculations indicate that it is not in danger of colliding with Earth in the next decade. If it had collided with the , there is a possibility that serious damage would have occurred.

A movie summary of a ridiculous moment of a meteorite that crashed into Russia - GIGAZINE

But it wasn't until July 15 that 2023 NT1 was spotted by South African telescopes, part of the Asteroid Earth Impact Final Warning System (ATLAS) , which detects asteroids about to hit Earth. .

The delay in detection of 2023 NT1 was due to the fact that it was moving toward the Earth from the direction of the Sun. Since the sun is a very bright celestial body, it is difficult to find an approaching asteroid even if the telescope is pointed in the same direction, and it may be possible to notice its existence after passing near the earth.

The European Space Agency (ESA) is planning a mission called ' NEOMIR ' to detect asteroids coming from the direction of the sun. NEOMIR will launch a satellite into orbit around the Lagrangian point (L1) between the sun and the earth, and detect asteroids coming from the direction of the sun, which are difficult to observe from the earth.The satellite launch is scheduled for 2030. I'm here.