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Current Affairs Brain Booster for UPSC & State PCS Examination

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Topic: Asteroid Bennu

Why in News?

• On Oct. 20, 2020, NASA’s OSIRIS-REx spacecraft successfully descended to the surface of asteroid Bennu and collected rocky material from sample site Nightingale during its Touch-andGo (TAG) sample collection maneuver.
• Two days later, the mission team received images from OSIRIS-REx confirming the spacecraft had collected more than enough material to meet one of its main mission requirements – acquiring at least 2 ounces (60 grams) of the asteroid’s surface material.

Asteroid Bennu

• The asteroid was discovered by the Lincoln Near-Earth Asteroid Research (LINEAR) survey on September 11, 1999.
• Bennu’s original designation was 1999 RQ36. In 2013, a third-grade student named Michael Puzio won a contest to name the asteroid.
• Bennu is a B-type asteroid, containing carbon and several other minerals in significant amounts.
• Due to the high carbon content, Bennu is able to reflect about 4% of the sunlight it receives, much less than a planet like Venus with 65% reflection. Earth reflects 30% of the sunlight it receives.
• Moreover, about 20% to 40% of the interior of the asteroid is empty space.
• As per scientists, Bennu was formed about 4.5 years ago, within the first 10 million years of the formation of our solar system.
• Bennu has drifted into near-Earth space because of gravitational interactions with giant planets and the gentle push of heating from the Sun.
• Bennu's density is only about 30 percent more than water. This suggests the asteroid is probably a loose collection of rocks, like a pile of rubble.
• Bennu has a close approach to Earth every six years.
• Scientists estimate Bennu has a 1‐in‐2,700 chance of impacting the Earth during one of its close approaches to the Earth in the late 22nd century.

NASA’s Interest in Bennu

• Bennu is a Near-Earth Asteroid (NEA). It is an Earth-crosser and potentially hazardous asteroids (PHA), which is why it is important for scientists to gather information about it.
• It is roughly as tall as the Empire State Building and is 321 million kilometers away from the Earth.
• Apart from the fact that it could be hazardous and closer to the Earth, Bennu has also not undergone any significant changes since it was formed billions of years ago.
• It contains rocks as well as chemicals dating back to when the solar system was formed.
• According to NASA, the organic material which scientists are hoping to find in the sample from Bennu does not come from Biology necessarily, but it could help them in further understanding how asteroids rich in organic material helped catalyse life on Earth.
• Any alteration in Bennu’s orbit could lead to a collision between the asteroid and the Earth, which is why this study is also significant.

The OSIRIS-REx mission

• OSIRIS-REx marks the first mission by NASA to collect and deliver to Earth samples from an ancient asteroid.
• The US space agency aims to collect at least 60 grams of dust and rocks from the asteroid and bring them back.
• This, NASA claims, would be the largest amount of celestial material brought back to Earth since the Apollo era.
• OSIRIS-REx was launched back in 2016, and it started orbiting asteroid Bennu in December 2018.
• For the past two years, the spacecraft had been trying to match the asteroid’s velocity, while also studying and capturing images of its surface for potential landing sites and providing data for scientists to study how the Sun light has been affecting Bennu’s orbit.