Why in news?
- NASA’s first asteroid samples fetched from deep space was parachuted into the Utah desert on September 24.
- The asteroid hunting spacecraft OSIRIS-Rex dropped a capsule containing pristine asteroid material in the Utah desert.
- In a flyby of Earth, the spacecraft released the sample capsule from 100,000 km out.
- The small capsule landed four hours later on a remote expanse of military land, as the mother-ship set off after another asteroid.
- Osiris-Rex is already chasing the asteroid Apophis, and will reach it in 2029.
What’s in today’s article?
- OSIRIS-Rex
- Asteroid
- News Summary
What is OSIRIS-Rex?
- Name stands for
- OSIRIS-Rex stands for - Origins, Spectral Interpretation, Resource Identification, Security, Regolith Explorer.
- About
- OSIRIS-REx is NASA's first mission to collect a sample from an asteroid.
- The spacecraft launched in September 2016 and arrived at the near-Earth asteroid Bennu in December 2018.
- In October 2020, OSIRIS-REx briefly touched down on Bennu to collect a sample from the surface.
- Using a long stick vacuum, it grabbed rubble from the small roundish space rock in 2020.
- The sample was brought back to Earth for study.
- By the time it returned, the spacecraft had logged 6.2 billion km (4 billion miles).
- This sample return mission aims to provide valuable insights into the early history of our solar system and the potential for asteroid impacts on Earth.
- Goal
- to understand the origins of our solar system,
- study the composition of the asteroid, and
- collect a sample of regolith (surface material) from Bennu.
- NASA’s third sample return mission
- Osiris-Rex was NASA’s third sample return from a deep-space robotic mission.
- The Genesis spacecraft dropped off bits of solar wind in 2004, but the samples were compromised when the parachute failed and the capsule slammed into the ground.
- The Stardust spacecraft successfully delivered comet dust in 2006.
What is Bennu?
- About
- Bennu is a near-Earth asteroid that is the target of NASA's OSIRIS-REx mission.
- Currently orbiting the sun 81 million km from Earth, Bennu is about one-half of a km across, roughly the size of the Empire State Building but shaped like a spinning top.
- It is believed to be the broken fragment of a much larger asteroid.
- Why Bennu was chosen for OSIRIS-Rex?
- Proximity to Earth
- The closest asteroids to Earth are called Near-Earth Objects (NEOs).
- NEOs are objects that orbit within 1.3 AU of the Sun. (1 AU = the distance between Earth and the Sun, or ~93 million miles).
- For a sample return mission like OSIRIS-REx, the most accessible asteroids for a spacecraft to reach are located between 1.6 AU and 0.8 AU.
- It completes an orbit around the Sun every 436.604 days (1.2 years) and every 6 years comes very close to Earth, within 0.002 AU.
- These close encounters give Bennu a high probability of impacting Earth in the late 22nd century.
- Size
- Asteroids with small diameters rotate more rapidly than those with large diameters.
- With a diameter less than 200 meters, an asteroid spin so rapidly that the loose material on its surface (regolith) can be ejected from it.
- The ideal asteroid has a diameter larger than 200 m (Bennu’s diameter – 490 m).
- Composition
- The most primitive asteroids are carbon-rich and have not significantly changed since they formed nearly 4 billion years ago. (Bennu is also carbon-rich asteroid)
- This means it may contain organic molecules and other materials that could shed light on the early solar system and the origins of life on Earth.
News Summary: NASA’s first asteroid samples land on Earth
- The pebbles and dust delivered on September 24 represent the biggest haul from beyond the moon.
- Japan is the only other country to bring back asteroid samples. It had gathered about a teaspoon in a pair of asteroid missions.
- Preserved building blocks from the dawn of our solar system 4.5 billion years ago, the samples will help scientists better understand how Earth and life formed.
