NASA’s first asteroid samples land on Earth

What’s in today’s article?

• What’s in today’s article?
• Why in news?
• What is OSIRIS-Rex?
• What is Bennu?
• News Summary: NASA’s first asteroid samples land on Earth

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 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.

Q1) What is regolith?

Regolith is a layer of loose material that covers solid rock. It includes dust, soil, broken rocks, and other related materials. Regolith is found on Earth, the Moon, some asteroids, and other planets. 

Q2) What is asteroid?

An asteroid is a small, rocky, and often irregularly shaped object that orbits the Sun. Asteroids are one of the fundamental building blocks of our solar system and are primarily found in the region between the orbits of Mars and Jupiter, known as the asteroid belt. However, they can also be found in other locations within the solar system.

Source: NASA’s first asteroid samples land on Earth after release from spacecraft | Solar System Exploration - NASA | The University of Arizona