What is the asteroid Bennu? One of the most dangerous space rocks we know of

NASA has given recently revised figures on the threat posed by asteroid 101955 Bennu.

In a study released Wednesday, NASA researchers said the probability of Bennu hitting Earth in the year 2300 is about 1 in 1750. They also found September 24, 2182 to be “the unique date. most important “for the risk of impact, with a probability of 1 in 2,700, according to the press release from the space agency.

Bennu has been the subject of scientific investigations for years, especially since the arrival of the OSIRIS-REx probe in the vast space rock in December 2018.

NASA describes the asteroid as one of the two most dangerous in the solar system, although the risk of impact is still very low.

Aside from impact threats, Bennu is of scientific importance for a number of reasons. On the one hand, the average orbital distance of the asteroid from the sun is around 105 million miles, which is relatively close to that of Earth at 93 million miles.

Additionally, it is a rare type of asteroid known as Type B. This means that it is both very old – scientists believe it formed more than 4.5 billion years old – and rich in carbon and may contain organic compounds.

On and under its black surface, Bennu may contain chemicals and rocks from the birth of the solar system.

Plus, at 510 meters (1,673 feet) pole-to-pole, Bennu is tall enough for a fact-finding mission.

Surface sample

For these reasons, Bennu was selected as a target for OSIRIS-REx, and from late 2018 until early this year, a probe circled the space rock to collect as much data as possible about its orbital path, its size and shape, mass, composition. and turn. Importantly, he also grabbed a surface sample.

The OSIRIS-REx spacecraft began to slowly move away from Bennu in April of this year and left for a two-year cruise to Earth about a month later.

The probe is expected to return its surface sample from Bennu, described by NASA as “pristine and precious cargo”, to Earth on September 24, 2023.

Bennu approaches Earth once every six years and orbits at an average speed of about 63,000 miles per hour. It takes about 1.2 years to fully orbit the sun and rotates every 4.3 hours.

Scientists expect to further improve Bennu’s Earth impact risk assessment in 2037, when the asteroid moves closer to Earth and allows them to collect radar data.