NASA's OSIRIS-REx spacecraft touched asteroid Bennu on 20 October 2020 to grab a sample of its surface. Click "Simulate TAG" below to replay the touch-and-go maneuver and watch the arm sink into Bennu's surprisingly loose surface.
Published figures (NASA OSIRIS-REx mission; TAGSAM sink-depth finding published in Science and Science Advances): Bennu is a top-shaped, rubble-pile near-Earth asteroid about 490 m across, spinning once every 4.3 hours. OSIRIS-REx touched down at the "Nightingale" site on 20 October 2020, firing a burst of nitrogen gas to stir loose material into its TAGSAM head - which sank about 48-50 cm into the surface, far deeper than engineers expected. The mission returned 121.6 g of asteroid material to Earth on 24 September 2023.
Click "Simulate TAG" to watch the spacecraft descend, touch down, and back away with the sample. Drag to orbit the camera and scroll or pinch to zoom.
Bennu + OSIRIS-REx TAG Sample Return 3D Explorer
This browser explorer replays NASA OSIRIS-REx's real touch-and-go sample grab on asteroid Bennu. Click "Simulate TAG" to watch the spacecraft descend, extend its arm, sink into the surface, and back away with a piece of a 4.5-billion-year-old asteroid.
On 20 October 2020, OSIRIS-REx touched down at a site nicknamed "Nightingale" on Bennu, a rubble-pile asteroid about 490 m across. Its TAGSAM arm fired a burst of pressurized nitrogen gas to stir loose surface grains into a collector head - and then sank roughly 48 to 50 cm into the ground, far deeper than engineers had planned for. Follow-up studies led by Dante Lauretta and Kevin Walsh found that Bennu's near-surface material is packed so loosely, and bonded so weakly, that it behaves more like a bed of loose granules than solid rock - NASA described the finding as showing Bennu's surface behaves "like a plastic ball pit." Had the spacecraft not fired its thrusters to back away immediately, it could have sunk in further.
- Click "Simulate TAG" to replay the descent, touchdown, and back-away sequence
- Watch the sampling arm visibly sink further into the surface on contact
- Read the live facts panel, including the real returned-sample mass and return date
- Click "Reset" to return to the idle state and replay the sequence again
- Drag to orbit the camera around Bennu, scroll or pinch to zoom
- Runs fully in the browser with the vendored three.js engine - no account, no upload
| Fact | Value |
|---|---|
| Diameter (equator) | about 490 m, top-shaped rubble pile |
| Rotation period | 4.3 hours (4.296 h sidereal) |
| Bulk density | about 1.19 g/cm3, roughly half empty space |
| Surface boulders > 10 m | more than 200 |
| OSIRIS-REx launch / arrival | 8 September 2016 / 3 December 2018 |
| TAG sample collection | 20 October 2020, site "Nightingale" |
| TAGSAM sink depth on contact | about 48-50 cm |
| Sample mass returned | 121.6 g (4.3 oz) - exceeded the 60 g minimum |
| Sample landed on Earth | 24 September 2023, Utah desert |
| Cumulative impact risk through 2300 | about 1-in-1,750 (single riskiest date 24 Sep 2182, about 1-in-2,700) |
These figures come from NASA's OSIRIS-REx mission pages, the peer-reviewed TAGSAM sink-depth studies published in Science and Science Advances, and NASA JPL's Center for Near-Earth Object Studies impact-risk analysis (Farnocchia et al., 2021). Bennu is tracked as a "potentially hazardous asteroid," but both its Torino Scale (0) and Palermo Scale (-1.40) ratings sit well below any level of public concern - the risk figures above describe a monitored, extremely low probability, not an active threat.
After delivering its sample, the spacecraft was renamed OSIRIS-APEx and redirected toward a real close approach of a different asteroid - see the Apophis 2029 Flyby 3D Explorer. For a different agency's touch-and-go sample-return mission, with its own artificial-impactor crater and a different sampling technique, see the Hayabusa2-Ryugu Sample Return 3D Explorer. For a spacecraft that deliberately crashed into an asteroid to test planetary defense rather than collect a sample, see the DART Asteroid Deflection 3D Explorer. For the general population Bennu belongs to, see the Asteroid Belt 3D Explorer.
Everything renders on your device with WebGL. The 3D engine loads once (about 0.7 MB) and is cached.
This is an educational approximation, not a physics or contact-dynamics simulation: Bennu's bumpy, boulder-scattered shape is a procedural teaching shape rather than a survey-accurate reconstruction, and the TAG sequence is a scripted state machine timed for clarity rather than a numerically integrated descent-and-touchdown solver. Bennu's on-screen spin is compressed for visibility - the real rotation takes 4.3 hours, far too slow to watch.
Frequently Asked Questions
What did OSIRIS-REx actually do at Bennu?
On 20 October 2020, NASA's OSIRIS-REx spacecraft touched down at a site nicknamed "Nightingale" on asteroid Bennu and fired a burst of pressurized nitrogen gas through its TAGSAM arm to stir loose surface material into a collector head.
Why did the TAGSAM arm sink into the surface?
Follow-up studies found Bennu's near-surface material is packed so loosely and bonded so weakly that it behaves more like a bed of loose granules than solid rock. The arm sank about 48-50 cm into the surface - deeper than engineers expected - and NASA described the finding as showing Bennu's surface behaves like a plastic ball pit.
How much sample did OSIRIS-REx bring back, and when?
The mission returned 121.6 g (4.3 oz) of asteroid material to Earth on 24 September 2023, landing in the Utah desert - far exceeding the mission's 60 g minimum requirement.
Is Bennu a threat to Earth?
No. Bennu is tracked as a "potentially hazardous asteroid" with a cumulative impact probability through 2300 of about 1-in-1,750, and its Torino Scale (0) and Palermo Scale (-1.40) ratings are both well below any level of public concern.
What happened to the OSIRIS-REx spacecraft after the sample return?
After releasing its sample capsule, the spacecraft was renamed OSIRIS-APEx and redirected toward a real 2029 close approach of a different asteroid, Apophis.
Is the scene on this page a real physics simulation?
No. This page is an educational approximation: Bennu's bumpy, boulder-scattered shape is a procedural teaching shape, and the TAG sequence is a scripted state machine timed for clarity rather than a numerically integrated descent-and-contact solver. Every date, mass, and distance figure shown is a real, independently published NASA figure.
Where do these numbers come from?
NASA's OSIRIS-REx mission pages, the peer-reviewed TAGSAM sink-depth studies published in Science and Science Advances (Lauretta and Walsh), and NASA JPL's Center for Near-Earth Object Studies impact-risk analysis (Farnocchia et al., 2021).