Project Pluto, Lunar Crater, and Earth craters are terms commonly used in space science. Recently, a piece from Chang’e 5-T1, a lunar mission of China, unintentionally hit the moon, creating a new crater and marking the first recorded case of space junk colliding with the moon. This event provoked interest in lunar craters, earth craters, space debris and its mitigation.
Project Pluto
Project Pluto is an initiative that monitors near-earth objects using earth-based telescope observations. The project was developed by American astronomer Bill Gray, who is also known for creating a popular astronomy software titled ‘Guide’. The trajectory, speed, and time of impact of the recent space junk incident were recorded using Project Pluto’s monitoring systems.
What is Space Junk?
Termed as space debris or space junk, these are non-functional materials orbiting Earth. They can range in size from a discarded rocket stage to small, microscopic chips of paint. The majority of this debris is found in the low Earth orbit, within 2,000 km of the Earth surface, although some can be detected in geostationary orbit, at a height of 35,786 km above the equator.
Kessler Syndrome
Hazardous effects of free floating space debris include potential collisions with operational satellites, rendering them dysfunctional. This scenario is known as Kessler Syndrome, named after NASA scientist Donald Kessler in 1978. As more countries launch satellites, the risk of collisions and subsequent creation of new space junk increases, potentially leading to a domino effect making the Earth’s orbit unusable.
Solution for Space Debris
The European Space Agency’s Clearspace-1 mission, scheduled to launch in 2025, will pioneer space debris elimination from orbit.
Lunar Craters
Lunar craters are bowl-shaped landforms created approximately 4.5 billion years ago by volcanic activity and cratering. There are hundreds of thousands, ranging from small to giant basins. The Moon’s largest crater is the South Pole-Aitken Basin. Over time, the moon has been impacted by comets and asteroid chunks, forming the numerous impact craters observed today. Due to Moon’s lack of water, atmosphere, and tectonic plates, there’s little erosion allowing craters over two billion years old to exist. Notably, the Mitra Crater on the Moon is named after Indian radio physicist Sisir Kumar Mitra.
Difference between Lunar and Earth Craters
Both Earth and Moon have been hit by multiple objects, such as asteroids, though craters on the moon are more permanent due to a lack of erosive processes like erosion, tectonics, and volcanism. Earth’s surface is constantly changing, erasing traces of past collisions. As a result, presently Earth has fewer than 200 known craters, while the moon’s absence of atmosphere, wind system and weather makes for no erosion of existing craters. The moon’s lack of tectonic activity also prevents new rock formation or shifts in current surface patterns. Lastly, recent history shows no signs of volcanism, ensuring craters aren’t covered.