Scientists have calculated what would happen if the Ryugu asteroid hit our planet. It was possible to predict the outcome of such a collision thanks to the analysis of samples returned to Earth by the Hayabusa2 spacecraft of the Japan Aerospace Exploration Agency (JAXA).

Presenting the results of the calculations at the 8th Planetary Protection Conference held in Vienna, Austria on Monday, April 4, JAXA Solar System Sciences Department Professor Satoshi Tanaka emphasized the importance of making similar assessments even for planetary protection efforts, for example asteroids. Ryugu, Which not currently a shock hazard.

Released in December 2014 Hayabusa2 It arrived at Ryugu, an asteroid about 900 meters wide, located 300 million kilometers away. Soil, in June 2018 after traveling for 42 months. In addition to collecting samples returned to Earth in 2020, Hayabusa2 made several rover landings on an asteroid and crashed into a space rock with two projectiles.

“The Hayabusa2 was successful in an experiment using two bullets weighing 1 kilogram. [2,2 фунта] Launched at 2 kilometers per second [1,2 милі на секунду]led to the formation of a crater about 20 meters in diameter. [66 футів]Tanaka said. “The bond strength of the rock must have been very low. The density is only slightly higher than water with very high porosity.”

Based on these facts, Ryugu, which is estimated to come no closer than about 62,000 miles (100,000 kilometers) from Earth, is considered a debris-heavy asteroid with low mechanical strength compared to normal rocks. This means that if the asteroid were headed for Earth, scientists would have to be very careful to prevent it from disintegrating if they tried to deflect it with something like the DART impactor that crashed into the asteroid-moon in September 2022. bimodal.

Tanaka explained that if the Ryugu asteroid were headed toward Earth and entered the planet’s atmosphere at a 45-degree angle and at about 38,000 miles per hour (17 kilometers per second), the asteroid would disintegrate into a pile of debris. interference from the direction. at an altitude of about 25 to 21 miles (40 to 35 km) from the planet’s surface.

This would lead to an “air blast” similar to the one observed over Russia in February 2013. Chelyabinsk The meteorite exploded about 19 miles (30 kilometers) above Earth. The result of the explosion in Chelyabinsk was a bright flash of light and an atmospheric explosion equivalent to an explosion of 400-500 kilotons of TNT. That’s 33 times the energy released by the atomic bomb that devastated Hiroshima at the end of World War II.

The air blast in Chelyabinsk injured about 1,500 people, mainly due to the amount of rubble and broken glass. With a diameter of just 66 feet, the Chelyabinsk meteor was the largest object to enter Earth. earth atmosphere From space since 1908, but still only a fraction of Ryugu’s size.

Tanaka noted that we currently don’t know enough about the asteroid’s pulling force to estimate the size of the fragments that would hit our planet if Ryugu were to disintegrate in Earth’s atmosphere.

“Ryugu’s pulling force could be more than twice as large as current estimates, which could affect its impact on Earth,” Tanaka concluded. “The returned sample is in the process of completing the initial analysis. Investigation of internal cracks will be important for a more accurate impact assessment in the future. [астероїдів, таких як Рюгу] to the Earth.”