NASA has captured an incredible close-up shot of plumes of dust and rocks erupting from the surface of near-Earth asteroid Bennu as it spins through the solar system.
Researchers from the University of Arizona have been studying the images taken by the navigation camera on the OSIRIS-REx spacecraft.
The high-resolution images were taken as part of a NASA mission to bring samples of the asteroid – that is about 300,000miles away – back to Earth for scientists to study.
These images offer a detailed look at small-scale rock and particle loss from an active asteroid for the first time, say researchers.
Previous studies have been limited to only the largest ejections seen from Earth.
The images sent back of Bennu by OSIRIS-REx show examples of lots of tiny dust and rock particles orbiting the space rock – as seen in this image
More than 20,000 known near-Earth asteroids are travelling around the solar system at any given time according to NASA.
‘From Earth the vast majority appear inert with no evidence smaller bits break free from the surface’, according to Dante Lauretta, the lead author of the paper.
‘Although rare, a small number of asteroids have been observed actively ejecting dust and particles in quantities large enough to create temporary clouds or comet-like tails viewable from Earth-based telescopes.’
In late 2018, OSIRIS-REx – which stands for Origins, Spectral Interpretation, Resource Identification, Security, Regolith Explorer – arrived at Bennu.
The near-Earth asteroid is a roughly spherical rock about 1600feet in diameter.
Features at the surface suggest it could be 100million to one billion years old, and likely originated in the main Asteroid Belt between Mars and Jupiter.
Mass losses from the surface appear as bright points of light in the OSIRIS-REx images according to Dr Lauretta.
According to the results, some of the objects remained in orbit for days before re-impacting with the surface, while others escaped into interplanetary space.
They identified small, third of an inch sized objects travelling just above the surface.
‘Further analysis of the trajectory of the material revealed three discrete events during which material was ejected from the surface’, according to Dr Lauretta.
The authors suggest that micro-meteorite impacts as well as dehydration and thermal stress fracturing are the possible causes of the particle ejection.
OSIRIS-REx (seen here as an artist impression over the asteroid) was first launched in 2018 on a mission to fly to a near-Earth asteroid, take samples of rock from the surface then fly back to Earth with the samples by 2023
‘Bennu shows that – from Earth’s perspective – an apparently inactive asteroid can harbour complex dynamics of debris re-impacting the surface’
‘It can also feed the interplanetary dust cloud, with yet unknown implications for its evolution’, said Jessica Agarwal from the Max Planck Institute, writing in a related articles on the photographs.
NASA will announce the site on the Bennu that it will take rock samples from within the next few days.
After selecting the four candidate sample sites in July – named Sandpiper, Osprey, Kingfisher, and Nightingale – NASA had OSIRIS-REx perform a month long series of fly-overs to examine each site in more detail.
NASA has had OSIRIS-REx fly over four potential sites it hopes to take a sample from and then bring that sample back to Earth by 2023. The sites seen here are named after birds – Nightingale, Kingfisher, Osprey and Sandpiper
While the mission is one step closer to collecting a sample, observations have revealed that even the best candidate sites on Bennu pose significant challenges to sample collection, according to the space agency.
‘Sample site selection really is a comprehensive activity. It requires that we look at many different types of data in many different ways.
‘[This is] to ensure the selected site is the best choice in terms of spacecraft safety, presence of sampleable material, and science value,’ said Heather Enos, OSIRIS-REx deputy principal investigator.
‘Our team is incredibly innovative and integrated, which is what makes the selection process work.’
Earlier papers examining OSIRIS-REx’s observations suggested the presence of hydrated minerals all over the ancient object.
It’s thought that an asteroid like this could have delivered carbon-rich material to Earth long ago.
The latest researching examining the ejections of material has been published in the journal ScienceMag.
HOW WILL NASA’S OSIRIS-REX MISSION TO TAKE SAMPLES FROM AN ASTEROID WORK?
Osiris-Rex is the first US mission designed to return a piece of an asteroid to Earth.
Scientists say the ancient asteroid could hold clues to the origin of life.
It’s believed to have formed 4.5 billion years ago, a remnant of the solar system’s building blocks.
The spacecraft launched on September 8, 2016 at 19:05 EST aboard an Atlas V rocket.
After a careful survey of Bennu to characterise the asteroid and locate the most promising sample sites, Osiris-Rex will collect between 2 and 70 ounces (about 60 to 2,000 grams) of surface material with its robotic arm and return the sample to Earth via a detachable capsule in 2023.
To capture samples on the surface, the craft will hover over a specific area and ‘will be sent down at a very slow and gently’ 4 inches (10 cm) per second.
The spacecraft will also carry a laser altimeter, a suite of cameras provided by the University of Arizona, spectrometers and lidar, which is similar to radar, using light instead of radio waves to measure distance.