Syllabus: GS3/ Science and technology
Context
- Recently, the news regarding the potential threats of near-Earth objects (NEOs) was widespread due to asteroid 2024 ON.
Impact of asteroids on Earth
- Around 100 tons of space material hits Earth every day in the form of tiny meteoroids. These small fragments burn up in Earth’s atmosphere.
- Asteroids about 50 meters in diameter are estimated to strike Earth once every 10,000 years.
- In 2013, a 20-meter wide asteroid entered the atmosphere and exploded about 30 km above a Russian town.
- The most dangerous are those larger than 1 kilometer in diameter, like the Chicxulub asteroid that caused the extinction of the dinosaurs 66 million years ago.
| Asteroids – Asteroids, also known as minor planets or planetoids, are small, rocky bodies that orbit the Sun. – They are remnants of the solar system’s formation, composed primarily of rock and metal. – Location: The majority of asteroids are found in the main asteroid belt, a region between the orbits of Mars and Jupiter. 1. Some asteroids go in front of and behind Jupiter, which are called Trojans. 2. Asteroids that come close to Earth are called Near-Earth Objects (NEOs). – Based on their composition, asteroids are categorized into three types: 1. C-type (carbonaceous): Rich in carbon, dark, and the most common type. 2. S-type (silicaceous): Made mostly of silicate materials and metals. 3. M-type (metallic): Composed mainly of metallic nickel-iron. Near-Earth Objects (NEOs) – The United Nations Office for Outer Space Affairs (UNOOSA) defines NEOs as any asteroid or comet that comes close to Earth’s orbit. – In technical terms, an object is classified as a NEO if its perihelion (the point in its orbit closest to the Sun) is less than 1.3 astronomical units (AU) from the Sun. 1. One astronomical unit is the average distance between Earth and the Sun, about 149.6 million kilometers. |
Planetary Defense Efforts
- Planetary defense, the detection of asteroids and comets whose impact with Earth could significantly affect the planet and the prevention or mitigation of any such impacts.
- In 2022, NASA’s Double Asteroid Redirection Test (DART) mission successfully crashed a spacecraft into an asteroid called Dimorphos. It demonstrated that a collision-based mission could change the direction of a celestial body and defend our planet.
- ESA is scheduled to launch a reconnaissance mission called Hera in 2024 to inspect the aftermath left by DART.
- Several space missions have been sent to study asteroids up close and collect samples, such as
- NASA’s OSIRIS-REx mission to asteroid Bennu and
- Japan’s Hayabusa2 mission to asteroid Ryugu.
India’s initiatives
- Also India is expected to collaborate with global planetary defense initiatives like International Asteroid Warning Network (IAWN), a virtual network of institutions that work to detect, track, and characterize near-Earth objects (NEOs).
- India and the US signed a Space situational awareness agreement in 2022.
Way Ahead
- Advances in space monitoring have improved the ability to predict and respond to potential threats.
- Scientists estimate that 95% of large, kilometer-sized NEOs have already been discovered, and none are expected to collide with Earth in the foreseeable future.
Source: IE
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