---
source: https://iinventedlight.com/library/notes/osiris-rex-mission.md
title: "OSIRIS-REx: bringing a piece of asteroid Bennu to Earth"
license: CC-BY-4.0
license_url: https://creativecommons.org/licenses/by/4.0/
source_license: "US government work, public domain; restated in our own words"
attribution: "Summary by iinventedlight (AI-assisted). Sources: NASA, NASA's OSIRIS-REx Mission to Asteroid Bennu, US government work, public domain; NASA, Bennu, US government work, public domain."
author: "iinventedlight (synthesis of cited sources); text drafted with AI assistance"
date: 2026-11-04
status: published
checked_on: 2026-11-04
as_of: 2026-11-04
confidence: medium
untested: "No observation or experiment was done; only the fetched government pages were read."
category: coverage-gaps
topic_area: "space science: missions"
tags: ['nasa', 'asteroids', 'bennu', 'sample-return']
sources:
  - id: S1
    title: "NASA's OSIRIS-REx Mission to Asteroid Bennu"
    publisher: NASA
    url: https://science.nasa.gov/mission/osiris-rex/
    accessed: 2026-11-04
    license: "US government work, public domain"
  - id: S2
    title: "Bennu"
    publisher: NASA
    url: https://science.nasa.gov/solar-system/asteroids/101955-bennu/
    accessed: 2026-11-04
    license: "US government work, public domain"
---
# OSIRIS-REx: bringing a piece of asteroid Bennu to Earth

**Answer:** OSIRIS-REx was the first U.S. mission to collect a sample from an asteroid and deliver it to Earth. It launched on Sept. 8, 2016, collected rocks and dust from the near-Earth asteroid Bennu on October 20, 2020, and delivered the sample to Earth on Sept. 24, 2023.

## The journey

- OSIRIS-REx used Earth's gravity to slingshot itself on a path toward Bennu, and the team used the flyby to test and calibrate the instrument suite.
- The spacecraft got its first glimpse of Bennu in August 2018, a grainy image taken at a distance of about 1.4 million miles (2.3 million kilometers).
- On return, it released a capsule with grains of Bennu over Earth's atmosphere. The capsule parachuted to the Department of Defense's Utah Test and Training Range, where the team retrieved it.

## Why Bennu

Scientists hope the Bennu sample will reveal whether asteroids that collided with Earth billions of years ago delivered water and other ingredients for life to our planet.

## About Bennu

- Bennu is a relatively small asteroid, about one-third of a mile wide at its equator.
- Its rocks formed nearly 4.6 billion years ago on a primeval world that has since been destroyed by a giant collision. Bennu coalesced from leftover rubble about 1 to 2 billion years ago.
- Bennu makes its closest approach to Earth every 6 years, coming within about 186,000 miles (299,000 kilometers) of our planet.

## Claims
- id: C1
  claim: OSIRIS-REx collected a sample from Bennu on October 20, 2020.
  source: S1
  evidence: "It collected a sample of rocks and dust from Bennu's surface on October 20, 2020."
- id: C2
  claim: OSIRIS-REx collected and returned a sample to Earth.
  source: S1
  evidence: "Collect asteroid sample and deliver it to Earth"
- id: C3
  claim: Bennu is about one-third of a mile wide at its equator.
  source: S2
  evidence: "Bennu is about one-third of a mile wide at its equator."

## Sources
- [S1] NASA's OSIRIS-REx Mission to Asteroid Bennu. NASA. https://science.nasa.gov/mission/osiris-rex/ . License: US government work, public domain. Accessed 2026-11-04.
- [S2] Bennu. NASA. https://science.nasa.gov/solar-system/asteroids/101955-bennu/ . License: US government work, public domain. Accessed 2026-11-04.

License: this note is CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Summary by iinventedlight (AI-assisted).