Kamo’oalewa

• 15 Nov 2021

Why in News

Recently, scientists have observed a quasi-satellite named Kamo`oalewa, tracking the Earth’s orbit around the Sun, could be a fragment from the moon.

• A mission to collect Kamo’oalewa’s samples has been scheduled for a launch in 2025.

Key Points

• Kamo’oalewa:
  
  • Discovered in 2016 (through the PanSTARRS telescope in Hawaii), Kamo’oalewa is a word that is part of a Hawaiian chant, and alludes to an offspring that travels on its own.
  • It is one of Earth’s quasi-satellites, a space rock that orbits the Sun, but remains relatively close to the planet – in this case about 9 million miles away.
  • The asteroid is roughly the size of a Ferris wheel – between 150 and 190 feet in diameter.
  • Because of its small size (about 50 metres wide), this quasi-satellite has been difficult for scientists to study, and little was known about it so far.
• Findings-Three Possibilities:
  
  • Part of Earth Moon:
    
    • It could have broken away from the Moon due to a possible impact, and gone on to orbit the Sun rather than the Earth-like its parent does.
    • Spectrum of reflected light from Kamo’oalewa closely matched lunar rocks from Nasa’s Apollo missions, suggesting it originated from the moon.
    • It is in an unusual orbit, one that would be unlikely for objects that had drifted towards Earth from the asteroid belt between Mars and Jupiter.
    • The team are unsure how the piece of moon came to be adrift in space, in part, because there are no other known asteroids with lunar origins. However, they narrowed down the timeframe for the violent event to have occurred between 1,00,000 and 500 years ago.
  • Near Earth Objects:
    
    • Captured in its Earth-like orbit from the general population of Near Earth Objects.
  • Earth’s Trojan Asteroids:
    
    • It originated from an as-yet-undiscovered quasi-stable population of Earth’s Trojan asteroids (Trojans are a group of asteroids that share an orbit with a larger planet).

Near-Earth Objects (NEOs)

• NEOs are comets and asteroids pushed by the gravitational attraction of nearby planets into orbits which allow them to enter the Earth’s neighbourhood.
• These objects are composed mostly of water ice with embedded dust particles.
• NEOs occasionally approach close to the Earth as they orbit the Sun.
• NASA’s Center for Near-Earth Object Study (CNEOS) determines the times and distances of these objects, when their approach to the Earth is close, through the Asteroid Watch Widget.

Source: IE