The OSIRIS-REx probe has been intensively investigating the Bennu asteroid for a year, which traverses the Solar System and is potentially a threat to Earth. Astronomers have published unusual images of its surface.
Thanks to them, we can take a closer look at the surface structure of this cosmic rock and see differences in height, and they reach up to 60 meters. A few months ago we could see the first map of this object. The model was created based on as many as 11 million measurements. The mission phase of mapping the surface of the object using an instrument called OLA, i.e. LiDARU, which was built by engineers from the Canadian Space Agency, is already completed.
The acquired data will allow astronomers to become familiar with these types of objects that could potentially threaten our planet. Such knowledge is extremely valuable, because thanks to it we will be able to create appropriate technologies that will allow us to try to neutralize cosmic rocks, as we have seen many times in sci-fi movies. The images will also be used to choose where the probe will take samples.
Scientists have so far presented the four most promising areas that have been named: Sandpiper, Osprey, Kingfisher and Nightingale. There are small rocks with a diameter of no more than 2.5 centimeters. They all have their pros and cons. The most important, however, is probe safety, so NASA engineers will choose a landing site that will safely accomplish this extremely important mission.
In recent months, the OSIRIS-REx spacecraft has been getting closer to Bennu's surface. In September, it orbited above it at an altitude of just 225 meters. The resulting images have a resolution of up to 2 cm/pixel. The most important phase of the mission, i.e. landing on the surface of the asteroid and taking samples from its surface is planned for this year or the beginning of the next. Importantly, this is the second mission in the history of humanity, after the Japanese Hayabusa-2 probe, to collect samples from the asteroid and deliver them to Earth.
When enough data is collected, including rock samples weighing about 2 kilograms, which is expected to happen by July 2020, the device will be sent on a return mission to our planet. This is to take place around March 2021. NASA predicts that rock samples will be in its testing laboratories around 2023. The device will land in Utah.
Amazingly, Bennu's first research shows us that it can be not only a sower of extermination, but also a sower of life. During the approach of the probe, scientists launched three spectrometers on its board. They collected interesting data about the surface composition of this asteroid. Data analysis has determined that the object contains minerals containing combined oxygen and hydrogen atoms, i.e. hydroxyl groups.
They are found throughout the planetoid in clay minerals. However, Bennu is too small to contain water by itself. It was probably present on the original planetoid, from which Bennu formed, and therefore we could detect it. It is a typical residue object after the early formation of the Solar System, so it is also an ideal material for research on primitive volatile and organic substances.
The Bennu planet will potentially pose a threat to our planet in 2135. The probability that Bennu will then collide with our planet is only 1:2700, but despite this fact, astronomers do not underestimate the whole situation, because if space rocks are involved, until the end nothing is certain.
Bennu is a cosmic rock with a diameter of 560 meters, weighs 70 million tons, moves at a speed of 28 km/s, orbits the sun every 437 days, and is on a collision line with Earth, approaching us every 6 years. Hitting it on our planet would cause an explosion of 1.15 gigatonnes TNT, about 23 times larger than the largest hydrogen bomb explosion. Once OSIRIS-REx has completed the study of the Bennu asteroid, we will get accurate estimates and based on this, scientists will create a roadmap for future missions of cosmic rock neutralization.