NASAs OSIRIS-REx Asteroid Sample Return Mission. Credit: NASAs Goddard Space Flight
Throughout the objective, the OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer) spacecraft invested about two years surveying Bennu, a carbonaceous rubble-pile asteroid about 500 meters (1,600 feet) in diameter. After considering the best locations to gather a sample, the objective team picked a site within a 20-meter (65-foot) crater, nicknamed Nightingale.
In October 2020, the spacecraft descended to the surface area and collected the sample, Lauretta et al. note. The spacecrafts Touch-and-Go Sample Acquisition Mechanism (TAGSAM) made contact and began sinking into the asteroids surface area before it launched a jet of nitrogen gas that set in motion sub-surface material and directed it into a collection chamber.
By evaluating imaging and spectral information taken throughout and after the samples retrieval, the team discovered that sub-surface material is darker and contains more fine particles than the overlying surface area. The procedure produced a debris plume and a new 9-meter-long (30-foot-long) elliptical crater.
This is what it appears like to punch an asteroid. Last month, NASAs robotic spacecraft OSIRIS-REx descended toward, thumped into, and then rapidly moved away from the little near-Earth asteroid 101955 Bennu. This video portrays the Touch-And-Go (TAG) sampling occasion over a three-hour duration. Credit: NASA/Goddard/University of Arizona/Lockheed Martin
Walsh et al. examined the physical homes of the material up to 10 centimeters (4 inches) listed below Bennus surface area, using images and accelerometer information. They reconstructed the forces applied on the spacecraft in the short period of time between when it first contacted Bennus surface and when it launched the nitrogen gas.
They found that the near-subsurface product is loosely jam-packed and less dense than the average of the entire asteroid, with very low cohesion. The high porosity and low product strength enable dust and other small particles to move within the sub-surface of the asteroid. Spectral and thermal information collected throughout the mission suggests these outcomes use to the whole asteroid, not just the sampling website.
” Spacecraft sample collection and subsurface excavation of asteroid (101955) Bennu” 7 July 2022, Science.DOI: 10.1126/ science.abm1018.
” Near-zero cohesion and loose packing of Bennus near-subsurface revealed by spacecraft contact” 7 July 2022, Science Advances.DOI: 10.1126/ sciadv.abm6229.
Last month, NASAs robotic spacecraft OSIRIS-REx descended towards, thumped into, and then rapidly moved away from the small near-Earth asteroid 101955 Bennu. They discovered that the near-subsurface material is loosely packed and less dense than the average of the entire asteroid, with very low cohesion. The high porosity and low material strength enable dust and other small particles to move within the sub-surface of the asteroid. Thermal and spectral information gathered throughout the mission suggests these outcomes apply to the entire asteroid, not just the sampling website.
OSIRIS-REx at Sample Site Nightingale.
Asteroid Bennus surface area consists of low-cohesion debris according to information collected during the sampling of the asteroid by the OSIRIS-REx objective. This is the finding of 2 new clinical studies– one each in Science and Science Advances.
According to the research study in Science by Dante Lauretta and colleagues, about 250 grams of sample (9 ounces) was gathered, which will be given Earth in 2023 for lab analysis.
The other study, released in Science Advances by Kevin Walsh and colleagues, examined the forces experienced by the spacecraft, finding that Bennus low gravity has actually led to a granular surface bed with weak cohesion in between particles.