Can be seen with a telescope

2.3 km asteroid races past the Earth

Almost on time for International Asteroid Day on June 30th, two large chunks pass by Earth within a good 40 hours. The dimensions of the two "potentially dangerous" celestial bodies would have devastating consequences in the event of an impact.

However, the European Space Agency's (ESA) asteroid defense office in Frascati near Rome gives the all-clear. Both cosmic chunks pose "zero danger", it says.

According to the report, the asteroid UL21, which has a diameter of around 2.3 kilometers, will fly past the Earth on Thursday at a distance of around 6.6 million kilometers - roughly 17 times the distance between the Earth and the Moon. In the event of an impact, an asteroid of this size would have catastrophic consequences.

The graphic shows the orbit of asteroid UL21.(Bild: ESA)

For comparison: in February 2013, an asteroid around 20 meters in size exploded over the city of Chelyabinsk, which has a population of over a million. Around 1500 people were injured by the blast wave, most of them by shattering window glass.

Can be seen with a good telescope
Despite the great distance, the asteroid can be observed with a better telescope when the night sky is clear, according to the ESA. The time is also perfect for this: according to the ESA, the celestial body is particularly close at 22:14 CEST.

Just over 40 hours later, shortly before International Asteroid Day on Sunday, a so-called NEO (Near-Earth Object) measuring 120 to 260 meters comes much closer to Earth. At only around 290,000 kilometers, it will be closer to our home planet than the moon (see graphic below).

The animated graphic shows the orbit of the asteroid 2024 MK, which will pass Earth on Sunday.(Bild: ESA)

According to the ESA, it can also be observed with a telescope in the night sky - but probably not from Europe: The closest approach will happen at 15:46 CEST, when it is still light. This asteroid with the catalog name 2024 MK was reportedly only discovered on June 16.

The discovery of such a large celestial body only a week before the flyby underlines the need to improve the ability to monitor potentially dangerous near-Earth objects, according to the ESA.

1.3 million asteroids are known
The space agencies are currently aware of around 1.3 million asteroids. The scenarios for the next 100 years are repeatedly played out for the 35,000 or so known near-Earth objects.