Scientists find a 'next step on a pathway to life' in space
Samples of matter returned from the asteroid Bennu support the theory that asteroids could have brought the building blocks of life to Earth, scientists report in a pair of new studies published Wednesday.
The samples were taken from the near-Earth asteroid Bennu by the NASA mission OSIRIS-REx, the first U.S. attempt to retrieve and analyze samples from an asteroid.
The findings do not show evidence for life itself, but they do suggest the conditions necessary for the emergence of life were widespread across the early solar system, increasing the odds life could have formed on other planets and moons, according to a NASA statement.
How Bennu samples were retrieved.
“We now know from Bennu that the raw ingredients of life were combining in really interesting and complex ways on Bennu’s parent body,” said Tim McCoy, the Smithsonian Institution’s curator of meteorites and the co-lead author on one of the new studies, in a statement. “We have discovered that next step on a pathway to life.”
The samples from Bennu came from NASA’s OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification and Security – Regolith Explorer) mission.
In 2018, the OSIRIS-REx mission arrived at the near-Earth asteroid Bennu to collect pristine samples, untouched by alterations induced by Earth's atmosphere, to be analyzed on Earth.
The spacecraft OSIRIS-REx returned to Earth in September 2023 after a yearslong mission to the nearby asteroid.
"NASA’s OSIRIS-REx mission already is rewriting the textbook on what we understand about the beginnings of our solar system," said NASA's Nicky Fox, in a statement. “Asteroids provide a time capsule into our home planet’s history, and Bennu’s samples are pivotal in our understanding of what ingredients in our solar system existed before life started on Earth."
Bennu has long intrigued researchers due to its near-Earth orbit and carbon-rich composition. Scientists theorized that the asteroid contained traces of water and organic molecules and that similar asteroids could have brought these materials to a primordial Earth.
Bennu’s parent asteroid, which formed around 4.5 billion years ago, seems to have been home to pockets of liquid water. The new findings indicate that water evaporated and left behind brines that resemble the salty crusts of dry lakebeds on Earth.
The findings were reported in two journal articles on Wednesday.
One, in the journal Nature Astronomy, found that the samples contained a diverse mixture of organic compounds. And the other, in the journal Nature, found that the samples contained minerals formed when brine – salty water –evaporated on Bennu's parent body, the type of wet environment where prebiotic organic chemistry may have brewed.
Present in the samples were 14 of the 20 organic compounds called amino acids that are used to make proteins - complex molecules that play indispensable roles in the structure, function and regulation of living organisms. Present also were all five nucleobases - the genetic components of DNA and RNA in all life on Earth.
Contributing: Reuters
This article originally appeared on USA TODAY: Asteroid Bennu samples give clues about origin of life on Earth
