What are the 10 reasons why you should investigate the asteroid 'Benne' that may collide with the Earth with a probe?

Discovered in 1999 the solar system asteroid Ben'nu in celestial objects (Bennu) is about 560 meters average diameter, also close to the Earth many times between about 200 years, the worst case even exists possibility of a collision . In September 2016 NASA's spacecraft " Osiris Rex " was launched and it is planned to take samples taken from the planetary surface of Benne like Earth's spacecraft "Hayabusa" to Earth, but it will float in this universe NASA has compiled 10 items to see where it is necessary to explore small asteroids.

Why Bennu? 10 Reasons - Solar System Exploration: NASA Science
https://solarsystem.nasa.gov/news/517/why-bennu-10-reasons/

◆ 01: Because it is close to the earth <br> Benny is an asteroid belonging to the Apollo group with a size orbit that is between the Earth and Mars. Asteroids in the Apollo group are known to have an existential threat to approach the Earth, and Benne is considered to be an asteroid with a high possibility of approaching them.

However, this can be thought of as being "a celestial body very close to the Earth" if it is backed up, which can be a great merit in carrying out asteroid exploration. A spacecraft Osiris · Rex investigating Bennes with such features is launched in September 2016 and then aims for Benny by "gravity swingby" using the gravity of the earth, and from 2019 to 2020 I am planning to arrive.

◆ 02: It is a heavenly body of a good size. Most of asteroids are rotating like the earth. Although the rotation cycle of the earth is 24 hours, some asteroids whose diameter is about 200 meters are rotated by several revolutions per minute. It is extremely difficult for explorers to approach such celestial bodies and it is extremely difficult to collect samples, and the possibility that Osiris · Rex aims to collect sediment " Legorus " on the ground due to centrifugal force due to rotation Yes.

The rotation cycle of the Benne with an average diameter of about 500 meters is 4.3 hours slow, so it is perfect for the spacecraft to work closely.

◆ 03: It is a very old astronomical object - Benne is considered a celestial body that exists since the solar system was formed. In order to know the history of the solar system in detail, it is the most effective way to investigate celestial bodies like Ben. Even on the earth, it is possible to see the appearance of the universe with meteorites falling from space, but in many cases the meteorite itself is "polluted" by the heat of the atmosphere and the atmosphere and the environment of the earth You can not see the way you are. Therefore, it is important to reach the asteroid in outer space and investigate as it is.

◆ 04: The figure in the past is preserved <br> Although some overlaps with the previous section, Benny saves the figure as it was when the formation of the solar system began about 5 billion years ago in a vacuum state space It is thought to be a "time capsule".

◆ 05: There is a possibility that it may contain substances that are the origin of life <br> Observations using the Earth telescope and the Space Telescope show that Benne is a carbonaceous or even carbon-rich asteroid. And carbon is a very important substance in life's birth. In addition to being highly likely to be abundant in organic molecules constituting life in Benne, there is a high possibility that the important element "water" for life is confined in minerals.

◆ 06: Have precious resources <br> Asteroids rich in natural resources such as iron and aluminum, rare metals such as platinum. For that reason, private companies that undertake space development, and in some cases even the state, are working on developing technologies to extract such resources. If we can use such resources, human beings will be able to extract rocket fuel by extracting water from the asteroid's soil and decomposing it into hydrogen and oxygen, when we aim for a Martian or later object It may become possible to utilize it as a "fuel station".

◆ 07: It leads to understanding of other asteroids Since astronomy was discovered in 1999, astronomers have conducted a survey of Bennes in observation from the earth. As a result, knowledge on many physical and chemical properties related to Benne was obtained, but that knowledge not only observes asteroids but also fills the gap of knowledge by combining studies of meteorites that have fallen on Earth Even it is obtained. By understanding the detailed information obtained from the sample to be collected by Osiris · Rex, human beings understand the extent of the difference between the prediction model and the actual figure, and further deepen the understanding of other celestial bodies It is expected to lead to things as well.

◆ 08: Elucidation of "force" caused by sunlight - It has been revealed from the observation data so far that the orbit of Benne has changed by 280 meters each year. This is thought to be due to the Yarkovsky effect that the orbits of small bodies are affected by the rotational force (moment) caused by the nonuniformity of heat radiation from the surface heated by sunlight. Osiris · Rex can also be used to understand the future orbit of Benne by measuring the state of the Jarkovsky effect in the Ben-Hu crust.

◆ 09: In order not to get close to the earth <br> As mentioned at the beginning, it is expected that Benna will be closely approaching the Earth in the future. Considering Jarukovsky effect, Benne is expected to approach Earth in a closer orbit than the moon in 2135, and it is considered to be further approaching from 2175 to 2195 thereafter. Still, the probability that Benny will collide with the Earth is calculated to be 0.07% at the maximum even for all the approaching events, and the risk of collision is low, but the data from Osiris · Rex indicates that the descendants of human beings have collided It is expected to be useful for understanding risks and taking countermeasures.

◆ 10: In order to share the sampled samples to scientists around the world <br> The samples collected by Benul will return to Earth on September 24, 2023 and plan to land in the Mojave desert in the USA. A quarter of the samples will be handed to the team of Osiris · Rex's researchers, but the remainder will be made available to scientists around the world and future technologies not yet developed In order to be useful for analysis, it is decided that some are preserved. NASA has also signed an agreement to share samples collected by "Osiris · Rex" and " Hayabusa 2 " with Japan's JAXA.