From UPSC perspective, the following things are important :
Prelims level : NEOs
Mains level : Not Much
NASA announced that a giant asteroid is expected to pass Earth at a safe distance, today.
Do you remember Osiris-Rex spacecraft of NASA? It is the only spacecraft to touch an asteroid called ‘Bennu’. NASA has brought back comet dust and solar wind particles before, but never asteroid samples.
This makes it a landmark feat and thus a hotspot for UPSC prelims.
What are NEOs?
- NASA defines NEOs as comets and asteroids nudged by the gravitational attraction of nearby planets into orbits which allows 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 as and when their approach to the Earth is close.
Significances of NEOs
- The scientific interest in comets and asteroids is largely due to their status as relatively unchanged remnant debris from the solar system formation process over 4.6 billion years ago.
- Therefore, these NEOs offer scientists clues about the chemical mixture from the planets formed.
- Significantly, among all the causes that will eventually cause the extinction of life on Earth, an asteroid hit is widely acknowledged as one of the likeliest.
- Over the years, scientists have suggested different ways to ward off such a hit, such as blowing up the asteroid before it reaches Earth, or deflecting it off its Earth-bound course by hitting it with a spacecraft.
About 163348 (2002 NN4)
- A Near-Earth Object (NEO), the asteroid is called 163348 (2002 NN4) and is classified as a Potentially Hazardous Asteroid (PHA).
- Asteroids with a minimum orbit intersection distance (MOID) of about 0.05 (AU is the distance between the Earth and the Sun and is roughly 150 million km) or less are considered PHAs.
- This distance is about 7,480,000 km or less and an absolute magnitude (H) of 22 (smaller than about 150 m or 500 feet in diameter).