Asteroid Bennu

Why in News?

Research on asteroid Bennu by NASA shows it contains life’s basic components, supporting the idea that asteroids supplied the ingredients for Earth’s first life.

• Bennu – It is a small, carbon-rich and near-Earth asteroid that passes relatively close to Earth about every 6 years.
• Naming History – Originally named 1999 RQ36, the asteroid was renamed Bennu in 2013 by a nine-year-old contest winner, Michael Puzio, who drew inspiration from an ancient Egyptian god.
• Size – Bennu is very small and about 0.5 km (one-third of a mile) wide at its equator.
• In contrast, Mercury, the smallest planet, is over 3,000 miles (4,800 km) across.
• Distance from the Sun – Bennu’s average distance from the Sun is 105 million miles (168 million km), which is just a little farther than Earth’s average distance of 93 million miles (150 million km).
• Orbit – Bennu currently orbits the Sun between Earth and Mars, and it belongs to the Apollo group of asteroids (over 21,000 members).
• Formation – Bennu likely broke off from a much larger carbon-rich asteroid about 700 million to 2 billion years ago.
• It likely formed in the Main Asteroid Belt between Mars and Jupiter, and has drifted much closer to Earth since then.
• Atmosphere – Bennu doesn’t have enough gravity to have an atmosphere.
• Potential for Life – Bennu’s extreme temperatures and lack of atmosphere make it inhospitable to life or liquid water.
  • Temperature range – 240°F (116°C) to -100°F (-73°C), because there is no atmospheric pressure, liquid water cannot exist on or under its surface.
• It was the target of NASA's OSIRIS-REx mission to collect an asteroid sample and bring it to Earth.

Quick Fact

References

1. The Hindu | Earthlife is made of space stuff, studies of asteroid Bennu hint
2. NASA | Bennu