Asteroids Ryugu and Bennu that both orbit between Earth and Mars may be chunks of the same giant space rock that was smashed apart in a collision
- Mathematical modelling suggests a possible relationship between the asteroids
- Astronomers at University of Arizona and Laboratoire Lagrange made prediction
- But tests on samples from both rocks will be needed in order to confirm this
The asteroids Ryugu and Bennu which orbit between Earth and Mars formed after a much larger rock was split apart, scientists have claimed.
Mathematical modelling suggests the pair – measuring 3,280-foot and 1,610-foot in diameter – formed after two centres of gravity were created.
But rock pulled from both will need to be tested to confirm the theory.
Samples from Ryugu are already onboard Japan’s Hayabusa2 spacecraft and expected to touchdown on Earth in late 2020.
And NASA’s OSIRIS-REx is scheduled to land on its suspected-sister by October 20, to collect further samples which will also be flown to Earth.
Mathematical modelling revealed Ryugu (left) and Bennu (right) may have formed from a larger asteroid that broke apart
The model showed after an asteroid shattered its pieces came together at two points
It was based on observations of asteroids in the Mars-Jupiter belt, where Bennu and Ryugu may have originated
Astronomers at the University of Arizona and Laboratoire Lagrange, Ivory Coast, modelled collisions in the Mars-Jupiter asteroid belt before making the proposal.
Their study, published in Nature Communications, showed fragments are ejected but then re-accumulate into a spinning-top shape – like that of both asteroids.
They also noted a difference in hydration between the possible-siblings, but said this did not discount the proposed relationship.
The team hopes to be able to measure the composition and age of formation of the samples from both asteroids to confirm their theory.
OSIRIS-REx has beamed images of Bennu’s rocky surface back to Earth, revealing the barren lunar surface.
The pictures show its chosen landing site – dubbed ‘Nightingale’ – which is located in a crater high up the asteroids northern hemisphere.
The spacaecraft will cut chunks 0.8 inches in diameter from the asteroid before beginning the journey home.
NASA has sent pictures of Bennu back to Earth. The image above shows the proposed landing site on the asteroid for its spacecraft OSIRIS-REx
OSIRIS-REx will collect small (less than 0.8 inches in diameter) rocks from the surface before beginning the journey back to Earth. (Artists impression)
Hayabusa2, not to be outdone, sent images of Ryugu’s lunar-surface back to Earth in February.
Its pictures revealed reddening in some of the rocks, leading scientists at the University of Tokyo to conclude that it once passed much closer to the sun.
‘Immediately after touchdown, Hayabusa2’s thrusters disturbed dark, fine grains that originate from the redder materials,’ wrote planetary scientist Tomokatsu Morota of the University of Tokyo and colleagues in their paper,
‘The stratigraphic relationship between identified craters and the redder material indicates that surface reddening occurred over a short period of time.’
‘We suggest that Ryugu previously experienced an orbital excursion near the Sun.’
Japan’s Hayabusa2 spacecraft has captured this picture of Ryugu’s surface. It revealed reddened rocks, which suggests at one point the asteroid may have passed near the Sun