nasa spacecraft gets up close with an asteroid that could one day collide with earth

NASA\'s Osiris spacecraft-
Rex only flew for more than two years after launching in September 2016 and eventually arrived at the asteroid 101955 Bennu, which may be colliding with the Earth.
The mission, which will bring grain back to Earth for our study, is the latest mission to return asteroid samples to Earth after NASA\'s Hayabusa 1 and 2 missions and stardust.
These data will help further reveal the origins of the solar system and how to protect the Earth from possible asteroid impacts.
The spacecraft will complete a detailed survey of Bannu\'s surface next year. (
492 m in diameter)
Including finding the most suitable landing site.
Once a site is selected, the spacecraft will land for about five seconds, collect surface material samples by nitrogen explosion, and release the material from the surface to the sampler head.
The spacecraft has enough gas to collect three samples from the surface.
This is expected to provide a sample of 60 to 2000 grams of surface weathered layer material. (
A material layer covering hard rock. .
It will return to Earth in 2021 - it will arrive here in 2023.
Asteroids are the remnants of the early solar system, which means they provide unique observations of their early composition.
Benu orbits the sun between the Earth and Mars.
Its ingredients are particularly interesting because we already know that it is rich in carbon.
This means that it may contain organic matter that has remained unchanged since the formation of the solar system.
It\'s not impossible for an asteroid like it to send the building blocks of life to the early Earth -- a task that can help us study this theory.
Although sample return is a major and complex part of this task, Osiris-
Rex will also study other aspects of asteroids.
During the investigation of the lunar surface, spacecraft will also look for plumes and natural satellites orbiting the earth.
The instruments on board will enable us to identify different chemicals on board.
This will help to find the most interesting and abundant sampling points with a resolution of about 2 meters.
Another reason is that the secrets of asteroid Banu threaten the Earth.
Bannu may collide with the earth in the future.
According to the study of Bannu orbit, it is theoretically believed that the gravitational interaction between two celestial bodies approaching the earth in 2060（750,000km)
It will change course slightly.
This means that between 2175 and 2199, the probability of Earth impacts totaled 2700 times. OSIRIS-
Rex may be able to help prevent such incidents.
One thing it will measure is the \"Jacovsky acceleration\" of an object.
This effect is a force acting on a rotating object in space, caused by the uneven heat released from the asteroid surface.
Once this is known, it is possible to investigate whether we can use this force to alter the orbits of Bannu and other threatening asteroids.
For example, using solar radiation to heat one side of a rock may be hotter than the other --- changing the rotation and trajectory of the rock.
The next two years will be an exciting little body study.
The mission will provide the most detailed analysis of carbon-rich asteroids and will provide answers to the evolution of the solar system and our own planets.
An analysis of the weathering layer will also tell us more about the effects of space weathering on the surface of small objects from intense solar radiation.
The acquisition method of this task is called \"touch sampling mechanism\".
\"Touch-and-shoot\" is exactly what a spacecraft must achieve, not a complete landing.
It will be very difficult, and we will have to wait a year to see if the new approach succeeds.
Let\'s pray that everything goes according to plan.
This article is republished from session under a creative shared license.
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Katherine Harris got funding from STFC.