The landing of the OSIRIS-REx capsule containing more than 200 grams of rock from the near-Earth asteroid Bennu landed at the US Department of Defense’s Utah Test and Training Range north of Salt Lake at 17:53 Moscow time. City. This was reported by NASA excitement.
Why Bennu?
(101955) Bennu is a near-Earth asteroid, 5.6 km in diameter, orbiting the Sun. Winter solstice (The point closest to the sun is) orbit is 11% closer to the Sun than Earth, and its apohelion is (farthest point) – 35% more. Its path periodically crosses the Earth’s orbit, but a collision with our planet is unlikely to occur in the next hundred years. According to scientists, this may happen with a probability of 1/2700. Benna was chosen as a research target not only because of its potential danger.
Experts are interested in its origin and exact chemical composition. The surface of the asteroid is very dark due to the large amount of carbon. Bennu was formed by the breakup of a larger body, a planetoid or protoplanet. This is evidenced by traces of metamorphism in its rock; It was subjected to heating and compression, and as a result, complex minerals could form. Such conditions occur only inside large bodies under the influence of gravity. According to planetary scientists, the asteroid’s progenitor had a diameter of about 100 km (dwarf planet Ceres is 480 km) and was located in the main asteroid belt.
Judging by the parameters of the craters on the surface of Bennu, it migrated to near-Earth orbit 1-2.5 million years ago. The change in orbit occurred due to the gravitational interaction with Jupiter and Saturn, as well as the Yarkovsky effect associated with the Sun: the asteroid is suppressed by photons of sunlight, but due to heating it emits infrared radiation, which creates a reactive reaction. impulse. As a result, the body’s trajectory can change in complex ways. This effect explains why the number of asteroids reaching Earth is higher than expected in previous calculations.
Bennu was chosen as the study site because it represents a “time capsule” untouched since nearly the formation of our planetary system.
Thanks to the extracted material, scientists will be able to reconstruct what the young solar system looked like and understand how planets formed there. Researchers are particularly interested in what chemical compounds were on the early Earth, where organic compounds came from, and how conditions developed for life to emerge. Finally, the mission will elucidate the impact of the Yarkovsky effect to understand whether an asteroid could collide with Earth in the foreseeable future.
How does OSIRIS-REx work?
The NASA mission was named after the Egyptian god Osiris because the project’s leadership loves ancient mythology — although technically “OSIRIS-REx” is an acronym for the list of assigned research missions. The device was launched on an Atlas V rocket on September 8, 2016. The journey to asteroid Bennu took more than two years, and after reaching it, OSIRIS-REx entered a periapsic orbit of approximately 1.75 km and began mapping. area.
The device is equipped with a set of cameras, one of which documents the taking of rock samples, visible, infrared and X-ray spectrometers, lidar to analyze the chemical composition of the surface. (laser “radar”) to create 3D maps of the asteroid and TAGSAM a device to collect geological samples.
On October 20, 2020, OSIRIS-REx slowed down and landed on Bennu. This was not a landing in the conventional sense, as the asteroid had almost no gravity; rather, the device touched the surface with its extended TAGSAM rod and immediately flew in the opposite direction.
The sampling device can be thought of as a container lowered upside down onto the asteroid. As soon as it touched the surface, nitrogen gas was released from its edges in a circle, and this gas threw small rocks inwards.
As a result, it was possible to collect about 250 grams of material, while the rock did not allow the flexible valve to close, so the grains of sand gradually flowed into space. Therefore, the container was placed as quickly as possible in the landing capsule, which was expected to return to Earth.
Samples escaping from the container
NASA
The device’s return journey to Earth began in April 2021 and took a year and a half. OSIRIS-REx, which passed by the planet 100 kilometers above the Pacific Ocean, continued its flight by lowering the capsule. In 2029, near-Earth asteroid 99942 will reach Apophis and explore it in the same way as Bennu, but without sampling. However, the device will approach the surface and blow away the surface layer of regolith (residual soil) with a jet stream to expose the subsoil.
“Star dust”
OSIRIS-REx is not the first landing mission to an asteroid, or even the first time asteroid samples were returned to Earth. The American spacecraft NEAR Shoemaker became the first spacecraft to explore the near-Earth asteroid (433) Eros, landing on a small body of the Solar System in 2001. In 2014, the European Rosetta mission performed a soft landing on short-period comet 67P/Churyumov-Gerasimenko.
For the first time, material from small bodies of the Solar System came to Earth artificially in 2006 – then the NASA Stardust apparatus flew from the tail of comet 81P/Wilda and delivered to scientists a capsule “stuck” on it. In 2010, the Japanese Space Agency’s Hayabusa mission returned 1,500 asteroids (25143) Itokawa to Earth. In 2018, the Hayabusa-2 lander retrieved the 5g asteroid (162173) Ryugu for earthlings. Thus, OSIRIS-REx set a record for the mass of the delivered cargo, which will make it possible to make a more complete conclusion about the composition of the asteroid.
Source: Gazeta
Barbara Dickson is a seasoned writer for “Social Bites”. She keeps readers informed on the latest news and trends, providing in-depth coverage and analysis on a variety of topics.