Context:
A team of astronomers has discovered three massive near-Earth asteroids hiding in the glare of the Sun. Of these, one called 2022 AP7 is believed to be the largest planet killer-sized asteroid to be spotted in nearly a decade, and is “potentially hazardous” to Earth.
Relevance:
GS I: Geography
Dimensions of the Article:
- What is an asteroid?
- What about the 2022 AP7 asteroid?
- Is there an immediate threat to Earth?
What is an asteroid?
- Asteroids are rocky objects that orbit the Sun, much smaller than planets. They are also called minor planets. According to NASA, there are 994,383 known asteroids, the remnants from the formation of the solar system over 4.6 billion years ago.
- Asteroids are divided into three classes.
- First are those found in the main asteroid belt between Mars and Jupiter, which is estimated to contain somewhere between 1.1-1.9 million asteroids.
- The second group is that of trojans, which are asteroids that share an orbit with a larger planet. NASA reports the presence of Jupiter, Neptune and Mars trojans. In 2011, they reported an Earth trojan as well.
- The third classification is Near-Earth Asteroids (NEA), which have orbits that pass close to the Earth.
- Those that cross the Earth’s orbit are called Earth-crossers.
- More than 10,000 such asteroids are known, out of which over 1,400 are classified as potentially hazardous asteroids (PHAs).
- Ryugu is also classified as a PHA and was discovered in 1999 and was given the name by the Minor Planet Center in 2015.
- It is 300 million kilometres from Earth and it took Hayabusa-2 over 42 months to reach it.
What about the 2022 AP7 asteroid?
- Among the three asteroids, one in particular stands out — the 1.5-kilometre-wide 2022 AP7 asteroid has an orbit that may someday put it on a collision course with our planet.
- At present, researchers have little information about the asteroid, including further details on its possible trajectory and its composition.
Is there an immediate threat to Earth?
- At present, the asteroid only crosses the Earth’s orbit while it is on the opposite side of the Sun i.e., when the Sun comes between the Earth and the asteroid.
- This will continue for several centuries as it takes the asteroid about five years to orbit the sun.
- An asteroid of this size could have a “devastating impact”, as the atmosphere would be inundated with dust and pollutants for years, preventing sunlight from entering the Earth’s surface.
- Over time, its orbital movement will slowly evolve to be more in sync with Earth’s.
- As of now, however it will stay well away from Earth.
-Source: Indian Express
