The solar system holds many secrets that scientists are still trying to uncover. To help shed light on these mysteries, researchers are turning to space rocks of all kinds that may hold clues to the lost story of our solar system's past. This approach is already paying off: in October 2023, NASA did just that OSIRIS-REx mission Discover water and carbon – Two precursors of life on Earth – on the 4.5 billion-year-old asteroid Bennu.
Among the thousands of asteroids clustering near Earth's orbit, minibodies — small cosmic bodies, whose orbits are partly governed by Earth and partly by other bodies in the solar system — may be prime candidates for learning about the origins of the solar system. Richard Benzelprofessor of planetary sciences at the Massachusetts Institute of Technology.
“[Minimoons] “He probably had a bit of a pinball experience in the inner solar system, being bounced and pulled by various planets.” Benzel told Live Science. “They finally found themselves in such a way that they were pulled into a fairly circular orbit near the Earth.”
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The Minimoons' relative proximity to Earth means that traveling to them and obtaining a sample would take much less time and fuel than it would to reach them Asteroids like Bennu. Although scientists are not yet sure where the small asteroids came from, a leading theory suggests that they originated in the main asteroid belt, which lies between Mars and Jupiter.
Near-Earth asteroids from this region, such as Bennu or the Little Moon, are “like time capsules.” Paul Appel“They give us clues about what the early solar system was like,” NASA's chief scientist for small-body exploration told Live Science. [and] “What were the circumstances?”
For example, in 2019, the Japan Aerospace Exploration Agency (JAXA) extracted samples from the diamond-shaped asteroid Ryugu, which is located more than 200 million miles (322 million kilometers) from Earth. Later analysis He revealed that the space rock contains star dust that predates our solar system, as well as “Prebiotic organic materials“, including many amino acids that organisms use to build the proteins that make up things like hair and muscles.
Collecting samples from small moons could help alleviate some of the big problems in current asteroid research. In most cases, scientists study pieces of asteroids that fell to Earth as meteorites. This could still teach us information about the early formation of the solar system, but it may be difficult to analyze depending on the state it is in, Appel said.
“When a meteorite falls to Earth, it is already contaminated” with moisture and gases in Earth’s atmosphere, he said. “When you're talking about organic molecules and water — more volatile type materials — going to the source and knowing what's there is really important. That's why we want to do these resampling missions, like Osiris Rex“.
OSIRIS-REx spacecraft The Bennu sample was dropped to Earth in SeptemberTo complete NASA's first successful mission to collect samples from a distant asteroid. The rocket is now on its next mission to explore the asteroid Apophis It is expected to arrive in 2029 when the cosmic rock passes within 19,800 miles (31,865 km) of our planet.
NASA will continue to study rocks and dust within Bennu over the next decade because “the abundance of carbon-rich materials and the abundant presence of water-bearing clay minerals are just the tip of the cosmic iceberg.” Dante LaurettaOSIRIS-REx principal investigator A Press conference in October.
For now, the success of the OSIRIS-REx mission has inspired scientists to plan the next stages of near-Earth exploration, and experts say the next easiest destination could be the mini-moon.
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