NASA?s OSIRIS-REx reaches the asteroid that could collide with Earth 166 years from now

By Elton Gomes

NASA’s Origins, Spectral Interpretation, Resource Identification, Security-Regolith Explorer (OSIRIS-REx) spacecraft completed its 1.2 billion mile (2 billion kilometre) journey to arrive at the asteroid named Bennu on Monday, the space agency said in a statement.

OSIRIS-REx’s mission is to scoop up Bennu’s gravel. However, it still has a lot of preparatory work to do before it can complete this mission.

OSIRIS-REx is currently about 11.8 miles (18.9 kilometres) from Bennu’s Sun-facing surface, and is set to begin a preliminary survey of the asteroid.

The spacecraft will commence flyovers of Bennu’s north pole, equatorial region, and south pole, getting as close as nearly 4 miles (7 kilometres) above Bennu during each flyover.

The $ 800 million unmanned spacecraft made rendezvous with the asteroid at around 12:10 pm PST (10:40 pm IST) on Monday. “We have arrived,” said Javier Cerna, an engineer at Lockheed Martin, as his colleagues at mission control in Littleton, Colorado, exchanged high-fives and cheered the accomplishment, as per an AFP report.

What is OSIRIS-REx?

NASA’s deep space probe OSIRIS-REx was launched in September 2016 on a first-of-its-kind mission. The spacecraft’s seven-year mission involves a close up survey of the asteroid Bennu. OSIRIS-REx will then collect a sample from Bennu’s surface and return to Earth for assessment. It is the third mission in NASA’s New Frontiers Programme.

Lockheed Martin Space in Denver built the spacecraft and is providing flight operations. Goddard and KinetX Aerospace are responsible for navigating the OSIRIS-REx spacecraft.

Goddard, NASA’s first space flight complex, is providing overall mission management, systems engineering, and the safety and mission assurance for OSIRIS-REx. Dante Lauretta of the University of Arizona, Tucson, is the principal investigator, and the University of Arizona is leading the science team, and the mission’s science observation planning and data processing.

What do we know about Bennu?

The asteroid named Bennu is an acorn-shaped rocky mass that is roughly a third of a mile wide. It orbits the sun at roughly the same distance as Earth. The asteroid is thought to be rich in carbon-based organic molecules that date back to the earliest days of the solar system.

Bennu was chosen from some 500,000 asteroids in the solar system because it orbits close to Earth’s path around the Sun. It is also the right size for scientific study, and is one of the oldest asteroids known to NASA. Scientists are hoping that it will reveal more about the early formation of the solar system.

“With asteroids, you have a time capsule. You have a pristine sample of what the solar system was like billions of years ago,” said Michelle Thaller, a spokeswoman for NASA’s Goddard Space Flight Centre, as per an AFP report. “That is why for scientists this sample is going to be far more precious than even gold.”

What is OSIRIS-REx’s mission?

OSIRIS-REx aims to collect at least 60 grams of dust and gravel from Bennu’s surface.

The spacecraft won’t land on Bennu, but it will use a three metre long mechanical arm in 2020 to momentarily touch down and pick up particles. The sample container will then be broken loose and directed towards Earth in 2021.

The collection will then be parachuted down to Utah. It would indicate the biggest such haul since the Apollo astronauts brough back rocks from Moon in the late 1960s and early 1970s.

The primary scientific goals of this survey are to refine estimates of Bennu’s mass and spin rate, and to generate a more precise model of its shape. This data will help scientists determine potential sites for sample collection in the future.

OSIRIS-REx’s mission will also help scientists investigate how planets formed and how life began. Such a probe will also improve our understanding of asteroids that could have an impact on Earth.

As NASA scientists learn more about Bennu, they’ll compare their findings with their counterparts from JAXA, the Japanese Space Agency. JAXA’s Hayabusa 2 spacecraft arrived at the asteroid Ryugu earlier in 2018.

The Japanese mission was the first to land moving rovers on the surface of an asteroid, and it will also send samples to Earth in 2020. Asteroid scientists are hoping to unlock a “bonanza” of discoveries from its findings.

OSIRIS-REx scientists expect to reveal the results of their early surveys of Bennu next week during the fall meeting of the American Geophysical Union in Washington, DC.

When is Bennu expected to collide with Earth?

Scientists predict that there is a one in 2,700 chance that the asteroid will catastrophically slam into Earth 166 years from now. This is why, Bennu is placed second on NASA’s catalogue of 72 near-Earth objects that are potentially capable of hitting the planet. If Bennu collided with Earth, it would probably cause a crater.

Is NASA planning to counter Bennu?

Earlier reports mentioned that NASA was preparing itself to deal with Bennu by drawing up plans to build a huge nuclear spacecraft named Hammer. The spacecraft would have been capable of shunting or blowing up dangerous space rocks, and of protecting life on Earth.

The Hammer (Hypervelocity Asteroid Mitigation Mission for Emergency Response) spacecraft would reportedly have been an eight tonne spaceship. It could have deflected a giant space rock, if it happened to hit Earth, according to a March 2018 report in the Telegraph.

As per these older reports, the 1,600 feet wide asteroid was circling the sun at 63,000 miles per hour. It was said to have been at a distance of 54 million miles from Earth.

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Elton Gomes is a staff writer at Qrius