A NASA spacecraft has completed its two billion km journey to an ancient asteroid after over two years.
The spacecraft arrived at asteroid Bennu on Monday and has since begun operating around the rock at a distance of around 19km.
It took seven minutes for word of the spacecraft’s successful arrival to reach flight controllers – with Bennu currently sitting some 122 million km from Earth.
It will now begin flyovers of the asteroid’s north pole, equatorial region, and south pole getting as close in as 7km each time.
Bennu is estimated to be just over 500 metres (1,600ft) across.
#WelcomeToBennu! After two years of travel – and more than a decade of planning and work by my team – I’m here. But Arrival is just the beginning… https://t.co/0bQPUwqUCp
Credit: NASA/Goddard/University of Arizona pic.twitter.com/VyPG3gRRdw
— NASA's OSIRIS-REx (@OSIRISREx) December 3, 2018
NASA’s OSIRIS-Rex (Origins, Spectral Interpretation, Resource Identification, Security-Regolith Explorer) spacecraft is about the size of an SUV.
It will shadow the rock for a year before taking rock samples to return to Earth in 2023.
The mission aims to gain a better understanding of how planets are formed and how life began.
It should also provide an insight into asteroids that could impact upon Earth.
Bennu is a B-type asteroid – meaning it is rich in carbon and organic molecules that make up life on Earth.
Achievement unlocked: "We have arrived!" Our @OSIRISREx mission reached asteroid Bennu, where it will spend almost a year mapping and studying to find a safe location to collect a sample. Watch: https://t.co/zI282xjLzc pic.twitter.com/VMPs7SIfSf
— NASA (@NASA) December 3, 2018
The mission also marks the first time NASA has studied an asteroid that could potentially strike the Earth in the future. It will attempt to discover the factors that could make an asteroid change its course and move closer to an Earth trajectory.
The space-craft will not actually land on the rock – but will use a three metre (10ft) mechanical arm to scoop up particles.
The sample container will then break loose and head back towards Earth in 2021.
When it arrives it will be carrying the largest sample returned from space since the Apollo era.
“As explorers, we at NASA have never shied away from the most extreme challenges in the solar system in our quest for knowledge,” said Lori Glaze, acting director for NASA’s Planetary Science Division.
“Now we’re at it again, working with our partners in the U.S. and Canada to accomplish the Herculean task of bringing back to Earth a piece of the early solar system.”
Congratulations @OSIRISREx ! Glad to hear you made it to Bennu. It looks like an amazing place. Can’t wait to see what you discover. #WelcometoBennu #spacebuddies https://t.co/CJR9q3Hi4D
— MASCOT Lander (@MASCOT2018) December 3, 2018
At the end of the month, OSIRIS-Rex will begin orbiting the rock – coming as close as 1.25km from its surface.
It comes as the Japanese spacecraft Hayabusa2 continues its mission to the near-Earth asteroid Ryugu.
The mission also aims to bring back samples from the asteroid – and will do so earlier with delivery expected in 2020.
Its sample size is expected to be far smaller than that OSIRIS-Rex expects to send back.
