Bennu asteroid, which has a 1 in 2,700 or 0.037% chance of hitting our planet in 2182, has been on the agenda for a while. The spacecraft OSIRIS-REx, which NASA sent to this asteroid, sent information that it landed on the target asteroid in 2020. The other day, our spacecraft returned to our planet safely with its samples and landed in Utah, USA.
The Bennu asteroid, which was the target of OSIRIS-REx, which was first launched on September 8, 2016, was thought to be 4.5 billion years old. We’re glad he returned safely, but many people don’t know exactly why the samples that came with this spacecraft are important. We will explain this.
What will success after 7 years bring to us?
As we said before, the Bennu asteroid is 4.5 billion years old. At least that’s what scientists’ calculations show. This indicates that the asteroid was formed at the time when our solar system began to form. This means that materials and amino acids from the pre-Solar system may be found on the asteroid.
The OSIRIS-REx vehicle was also sent to retrieve these materials. The materials, which are strictly protected to prevent contact with substances in the atmosphere, will be sent to different research centers for examination. It is also stated that some of it will be kept for examination in the coming years.
In order to better understand the importance of the asteroid, we can look at the following definition by Scientist Fred Jourdan: “They are the first bricks that enable the formation of planets.”
The materials of this sample, weighing between 149 and 350 grams, are not much different from meteorites that hit the Earth. So what makes Bennu special?
According to scientists, meteorites that enter our planet’s atmosphere are exposed to materials in the atmosphere, and therefore – although those that fall on our planet are examined – it is not possible to examine their pure form in space. When they fall to the ground, they are exposed to things like soil and snow. That’s why the Bennu asteroid is important because it was examined in situ and its materials still preserve their structures in space.
So why Bennu and not another asteroid?
First of all, Bennu is quite close to our planet. In addition, its movement around the Sun is similar to that of our planet. In addition, since Bennu is slightly larger in size compared to other small asteroids, it is easier for the spacecraft to land.
Bennu, which we can say has aged like wine, contains very old materials due to its age. It is predicted that these materials may be even older than our Solar system. Therefore, the Bennu samples can actually be seen as excavated historical documents. Of course, we will see these after the investigations.
It may not have come into contact with our planet, but did this asteroid remain untouched in space?
Frankly, Bennu is thought to have been involved in a major collision 1 or 2 billion years ago, but scientists state that the originality of the structure has not been significantly damaged.
In addition, NASA states that thanks to Bennu, the role that asteroids play in delivering the materials that enable the formation of life to the planet can be understood.
Because it is very likely that there are organic molecules rich in carbon in the samples taken from Bennu. Apart from carbon, it is thought that water is also among the minerals that make up the asteroid.
Bennu, which contains molecules and various materials rich in history, can also accelerate future space tourism and resource (fuel) research. It is stated by NASA that many companies are working on extracting these resources from asteroids rich in iron and aluminum. In this respect, asteroids may serve as gas stations in the future. Another important thing that can be taken from here is that the Bennu sample fresh from space may have a key role in our understanding of other asteroids.
Let’s briefly explain the last item, the Yarkovsky effect.
Relatively small astronomical objects rotate on their axis, just like our planet. That’s why those who do this around the Sun or other stars have a light and a dark side. The side exposed to light also reflects some of the incoming photons and absorbs others. That’s why the illuminated side gets hot.
When the heated side darkens, these absorbed photons are released back as it cools. Meanwhile, force is applied to the asteroid depending on its direction of rotation, and in this context, the asteroid either accelerates or slows down. The OSIRIS-REx vehicle was sent to closely monitor this effect and see to what extent it was happening. If this investigation, carried out specifically for Bennu, allows the orbits of other asteroids to be predicted, they can see which asteroid will pass close to our planet on which date.
For example, Bennu is predicted to be closer to the Earth than the Moon in 2135. According to NASA, the years 2175 and 2195 will be even closer than that. Although it seems unlikely that it will hit our planet, those who will live at that time will be able to find out how to escape the effects of other asteroids by looking at the current OSIRIS-REx study.
All these factors and other technical details that we have not mentioned make the OSIRIS-REx project critical in the field of space studies and space history.