Overview

Launched in 2016, NASA’s OSIRIS-REx mission traveled for seven years through deep space before returning to Earth in 2023. It successfully delivered 122 grams of dust and pebbles from asteroid Bennu, a celestial relic dating back 4.5 billion years. The samples, securely enclosed in a capsule, parachuted into the Utah desert. In January 2025, scientists published groundbreaking findings in Nature and Nature Astronomy, offering fresh insights into the building blocks of life.

Amino Acids: Tracing the Origins of Proteins

One of the most significant discoveries reported in Nature Astronomy was the detection of 14 amino acids, essential molecules used by life on Earth to construct proteins.

This finding confirms that organic molecules are present beyond Earth, but it also raises new questions. Amino acids can exist in two mirror-image forms—like left and right hands. On Earth, life predominantly uses the left-handed form, but Bennu’s samples contained an equal mix of both. This suggests that early Earth may have started with a balanced mixture, leaving scientists to wonder why life ultimately favored one over the other.

Nucleobases: The Blueprint of Life

The Bennu samples also contained all five nucleobases—adenine, guanine, cytosine, thymine, and uracil—the fundamental components of DNA and RNA, which encode genetic information and direct protein synthesis.

“These aren’t direct signs of life, but they are fundamental ingredients needed for life to emerge,” said Trevor Ireland, a researcher from the University of Queensland involved in the study.

“This discovery confirms that these materials were widespread in the early solar system, potentially playing a role in planetary formation and even the emergence of life—not just on Earth, but possibly on Mars as well,” he added.

Ammonia and Formaldehyde: A Chemical Recipe for Life

Scientists also detected high levels of ammonia in the Bennu samples, a crucial molecule in biological chemistry. Ammonia can interact with formaldehyde, another compound found in the samples, to create more complex molecules, including amino acids. Under the right conditions, amino acids link together to form proteins, the essential drivers of biological processes.

Evaporites: Traces of a Watery Past

Beyond organic molecules, the samples revealed 11 different minerals, including calcite, halite, and sylvite—all of which form when saltwater evaporates and leaves behind crystalline deposits. These minerals suggest that Bennu once had liquid water, an essential factor in prebiotic chemistry.

Similar briny environments have been found elsewhere in the solar system, such as Ceres, a dwarf planet, and Enceladus, a moon of Saturn. However, this is the first time a complete set of evaporite minerals has been observed in extraterrestrial samples, preserving evidence of an evaporation process that could have lasted thousands of years. Notably, trona, a mineral never before identified in space samples, was also found in Bennu’s dust.

“These studies complement each other beautifully, helping us understand how life’s essential components formed on an asteroid altered by water over time,” said Tim McCoy, curator of meteorites at the Smithsonian’s National Museum of Natural History.

Why This Discovery is Groundbreaking

While organic molecules have been found in meteorites before, this is the first time they have been retrieved directly from an asteroid in space, eliminating the risk of terrestrial contamination.

The findings strongly support panspermia, the hypothesis that asteroids and comets may have seeded planets with the necessary organic materials for life. This suggests that the early solar system was rich in these ingredients, increasing the likelihood that life could have emerged not just on Earth, but elsewhere in the cosmos.

“These compounds have been identified in meteorites before,” said NASA scientist Danny Glavin, “but detecting them in an uncontaminated space sample reinforces the idea that asteroids from distant regions of the solar system played a crucial role in delivering life’s raw materials.”

Are We Alone?

The OSIRIS-REx mission provides some of the strongest evidence yet that life’s fundamental ingredients are widespread in the universe. While most of the $1 billion sample cache has been preserved for future research, scientists stress the importance of additional sample-return missions to asteroids, comets, and moons to further investigate these findings.

China is set to launch its own asteroid sample return mission this year, while a mission to Ceres, a potentially water-rich dwarf planet, is gaining interest. Jupiter’s moon Europa and Saturn’s moon Enceladus remain prime candidates for exploration due to their subsurface oceans. Meanwhile, NASA has already gathered core samples from Mars, though their retrieval remains on hold as the agency determines the best method for bringing them back to Earth.

“Are we alone in the universe?” Dr. McCoy asked.

“That’s the fundamental question we’re working to answer.”

The Next Chapter Awaits

As we continue unraveling the mysteries of our cosmic origins, OSIRIS-REx is just the beginning. With upcoming missions set to return more pristine samples from distant worlds, the next few years could bring earth-shattering revelations about the nature of life and our place in the universe.

Buckle up—the greatest discoveries are yet to come!