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Updated: October 28, 2020 8:47:56 am
This photo from 11 August 2020 shows the sampling arm of the OSIRIS-REx probe during a test for an approach to the “Nightingale” sample site on the surface of the asteroid Bennu. (NASA / Goddard / University of Arizona via AP)
Tuesday, NASA’s OSIRIS-REx – Origins, Spectral Interpretation, Resource Identification, Security, Regolith Explorer – spacecraft briefly touched the asteroid Bennu, from where it is intended to collect samples of dust and pebbles and return them to Earth in 2023.
The asteroid was named after an Egyptian deity after a nine-year-old boy from North Carolina in 2013 who won NASA’s “Name that Asteroid” competition. The asteroid was discovered by a team from the NASA-funded Lincoln Near-Earth Asteroid Research team in 1999.
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, 994,383 is the count of known asteroids, the remnants of the formation of the solar system over 4.6 billion years ago.
Asteroids are divided into three classes. First, those found in the main asteroid belt between Mars and Jupiter, which is estimated to contain 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 also reported a terrestrial Trojan.
The third classification is Near-Earth Asteroids (NEA), which has 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, of which more than 1,400 are classified as potentially dangerous asteroids (PHAs).
What is the OSIRIS-REx mission?
This is NASA’s first mission to return a sample of the ancient asteroid. The mission is essentially a seven-year journey and will end when at least 60 grams of samples are returned to Earth. According to NASA, the mission promises to bring the largest amount of extraterrestrial material back to our planet since the Apollo era.
The mission launched in 2016, reached its goal in 2018, and since then the spacecraft has been trying to match the speed of the asteroid by using small rocket thrusters to reach it. He also used this time to examine the surface and identify potential sites for taking samples.
On Tuesday, the spacecraft’s robotic arm called TAGSAM (Touch-And-Go Sample Acquisition Mechanism), attempted to “TAG” the asteroid at a sample site that was no larger than a few parking lots and collected a sample.
The spacecraft contains five instruments intended to explore Bennu including cameras, a spectrometer and a laser altimeter. The departure window for the mission will open in 2021, after which it will take more than two years to return to Earth.📣 Follow Express Explained on Telegram
Why are scientists studying the asteroid Bennu?
Bennu is an asteroid about the height of the Empire State Building and located at a distance of about 200 million miles from Earth. Scientists study asteroids to look for information on the formation and history of planets and the sun, as asteroids formed simultaneously with other objects in the solar system. Another reason to track them is to look for asteroids that could be potentially dangerous.
It is for these reasons that scientists are interested in gathering information on this particular asteroid. It is significant that Bennu has not undergone drastic changes since its formation over billions of years ago and therefore contains chemicals and rocks dating back to the birth of the solar system. It is also relatively close to Earth.
How do chemicals and rocks offer scientists clues to the solar system?
Due to Bennu’s age, it is likely to contain material that contains molecules that were present when life first formed on Earth, where life forms are based on chains of carbon atoms. Even so, “organic material like the kind scientists hope to find in a Bennu sample doesn’t necessarily come from biology. However, further research by scientists would be needed to uncover the role played by organically rich asteroids in catalyzing life on Earth, ”says NASA.
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What do we know about the asteroid so far?
So far, we know that the asteroid is a type B asteroid, which implies that it contains significant amounts of carbon and various other minerals. Due to its high carbon content, the asteroid reflects about four percent of the light that hits it, which is very low compared to a planet like Venus, which reflects about 65 percent of the light that hits it. The Earth reflects about 30%.
About 20-40% of Bennu’s interior is empty space, and scientists believe it formed in the first 10 million years of the solar system’s formation, meaning it is around 4.5 billion years old. As with the high-resolution photographs taken by the spacecraft, the surface of the asteroid is covered with massive boulders, making it more difficult to collect samples from its surface.
There is a slim chance that Bennu, which is classified as a NEO (Near Earth Object), could hit Earth in the next century, between the years 2175 and 2199. NEOs are comets and asteroids propelled by the gravitational pull of nearby orbiting planets. which allows them to enter the neighborhood of the Earth.
© The Indian Express (P) Ltd
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