Topics Covered: Awareness in space.
Asteroid 465824:
Why in News?
NASA says asteroid 465824 2010 FR, which is twice as big as the Pyramid of Giza, may cross the Earth’s orbit on September 6.
- It is classified as a Near-Earth Object (NEO) and a potentially hazardous asteroid (PHA).
What are NEOs?
NASA defines NEOs as comets and asteroids nudged by the gravitational attraction of nearby planets into orbits that allow them to enter the Earth’s neighbourhood.
- These objects are composed mostly of water ice with embedded dust particles.
What is an asteroid?
Asteroids are rocky objects that orbit the Sun, much smaller than planets. They are also called minor planets. As per NASA, 994,383 is the count for known asteroids, the remnants from the formation of the solar system over 4.6 billion years ago.
Why most asteroids are found in only one region?
Most such objects can be found in the asteroid belt between Mars and Jupiter, which is estimated to contain somewhere between 1.1-1.9 million asteroids. The explanation for the concentration of asteroids in this belt comes from the formation of Jupiter, whose gravity brought an end to the formation of any planetary bodies in this region, as a result of which the smaller bodies kept colliding with each other, fragmenting into asteroids.
Other types of asteroids:
- Trojans, which are asteroids that share an orbit with a larger planet.
- Near-Earth Asteroids (NEA), which have orbits that pass close by the Earth. Those that cross the Earth’s orbit are called Earth-crossers.
Why do scientists track asteroids?
- To look for information about the formation and history of planets and the sun, since asteroids were formed at the same time as other objects in the solar system.
- To look for asteroids that might be potentially hazardous.
What are PHAs?
In the asteroid belt between Mars and Jupiter Over 1,400 asteroids are classified as potentially hazardous asteroids (PHAs).
- According to NASA, “Potentially Hazardous Asteroids (PHAs) are currently defined based on parameters that measure the asteroid’s potential to make threatening close approaches to the Earth”.
- Specifically, all asteroids with a minimum orbit intersection distance (MOID) of 0.05 au or less are considered PHAs.
How can asteroids be deflected?
The most drastic measure undertaken so far is the Asteroid Impact and Deflection Assessment (AIDA), which includes NASA’s Double Asteroid Redirection Test (DART) mission and the European Space Agency’s (ESA) Hera.
- The mission’s target is Didymos, a binary near-Earth asteroid, one of whose bodies is of the size that could pose a significant threat to Earth.
- In 2018, NASA announced that it had started the construction of DART, which is scheduled to launch in 2021 with an aim to slam into the smaller asteroid of the Didymos system at around 6 km per second in 2022.
- Hera, which is scheduled to launch in 2024, will arrive at the Didymos system in 2027 to measure the impact crater produced by the DART collision and study the change in the asteroid’s orbital trajectory.
InstaLinks:
Prelims Link:
- What are near earth objects?
- Classification of asteroids.
- Why most asteroids are found in the asteroid belt between Mars and Jupiter?
- What are potentially hazardous asteroids? How are they classified?
- Overview of NASA’s DART Mission.
Mains Link:
Differentiate between meteorite and asteroid.
Sources: Indian Express.
