As the times rely down to NASA’s OSIRIS-REx spacecraft’s Contact-And-Go asteroid sample assortment attempt, Southwest Investigation Institute scientists have served ascertain what the spacecraft can be expecting to return from the in the vicinity of-Earth asteroid Bennu’s surface. 3 papers revealed on line by Science on Oct. 8 discuss the color, reflectivity, age, composition, origin and distribution of components that make up the asteroid’s tough surface.
On October 20, the spacecraft will descend to the asteroid’s boulder-strewn surface, touch the floor with its robotic arm for a couple of seconds and acquire a sample of rocks and dust — marking the to start with time NASA has grabbed items of an asteroid for return to Earth. SwRI scientists played a purpose in the assortment of the sample internet sites. The to start with attempt will be built at Nightingale, a rocky area sixty six toes in diameter in Bennu’s northern hemisphere. If this historic attempt is unsuccessful, the spacecraft will consider once again at a secondary website.
Due to the fact the spacecraft arrived at Bennu in 2018, scientists have been characterizing the asteroid’s composition and comparing it to other asteroids and meteorites. The mission identified carbon-bearing compounds on Bennu’s surface, a to start with for a in the vicinity of-Earth asteroid, as very well as minerals that contains or fashioned by h2o. Researchers also studied the distribution of these components, globally and at the sample internet sites
“Our new studies show that organics and minerals related with the presence of h2o are scattered broadly close to Bennu’s surface, so any sample returned to Earth need to include these compounds and minerals,” said SwRI’s Dr. Vicky Hamilton, a coauthor on all a few papers. “We will look at the sample’s relative abundances of organics, carbonates, silicates and other minerals to those in meteorites to aid ascertain the scenarios that very best explain Bennu’s surface composition.”
Asteroid Bennu is a dark, rubble pile held jointly by gravity and imagined to be the collisional remnant of a substantially bigger major-belt item. Its rubble-pile character and seriously cratered surface signifies that it has experienced a tough-and-tumble daily life since being liberated from its substantially bigger dad or mum asteroid hundreds of thousands or even billions of many years ago.
“Boulders strewn about in the vicinity of the Nightingale website have shiny carbonate veins,” Hamilton said. “Bennu shares this compositional trait with aqueously altered meteorites. This correlation implies that at minimum some carbonaceous asteroids were being altered by percolating h2o in the early Photo voltaic Technique.”
The boulders on Bennu have assorted textures and shades, which could provide information about their variable exposure to micrometeorite bombardment and the solar wind above time. Finding out color and reflectance knowledge provide information about the geologic heritage of planetary surfaces.
“Bennu’s assorted surface incorporates plentiful primitive substance perhaps from various depths in its dad or mum body moreover a small proportion of foreign components from yet another asteroid household littered about its surface,” said SwRI’s Dr. Kevin Walsh, a coauthor of one particular of the papers. “In addition, both the principal and back-up sample internet sites, Nightingale and Osprey, are positioned in small spectrally reddish craters that are imagined to be extra pristine, having skilled significantly less area weathering than most of Bennu’s bluish surface.”
The OSIRIS-REx group is also comparing Bennu to Ryugu, yet another in the vicinity of-Earth asteroid. The two asteroids are imagined to have originated from primitive asteroid people in the inner major belt. The Japan Aerospace Exploration Company released Hayabusa2 in 2014 and rendezvoused with in the vicinity of-Earth asteroid Ryugu in 2018. After surveying the asteroid for a year and a 50 %, the spacecraft gathered samples and is predicted to return to Earth December six, 2020.
The sample returned by OSIRIS-REx, mixed with the surface context maps OSIRIS-REx has gathered, will strengthen interpretations of accessible floor and area telescope knowledge for other primitive dark asteroids. Evaluating returned Bennu samples with those of Ryugu will be instrumental for comprehending the variety in, and heritage of, asteroid people and the full asteroid belt.
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