2/24/2025
Asteroid samples collected by NASA’s OSIRIS-REx not only contain the pristine building blocks for life, but also the salty remains of an ancient water world. These findings support the idea that asteroids delivered the building blocks of life to our planet early in its history, and may have delivered them elsewhere in the solar system. The spacecraft originally launched in 2016 to visit the near-Earth asteroid Bennu. It returned in 2023, with 122 grams of dust and pebbles in its sample canister. This remains the biggest cosmic haul from beyond the Moon.
This was no small feat, as most of the delicate salts from the samples would have been stripped away upon return. “The discovery was only possible by analyzing samples that were collected directly from the asteroid then carefully preserved…on Earth.” The samples from Bennu were protected from excessive heat during atmospheric entry and exposure to terrestrial contamination. This eliminated concerns about contamination. Thus, it confirmed that if any important materials were collected from Bennu, they “…are in fact extraterrestrial in origin and formed in space, and are not contaminants from Earth.”
Dr. Daniel P. Glavin, one of NASA’s senior scientists for sample-return, confirmed the presence of such material. He revealed that the asteroid contained thousands of organic molecular compounds, including 14 of the 20 essential amino acids (i.e. molecules that combine to form proteins) and all five biological nucleobases (i.e. the components that make up the genetic code). Studies suggest that these ingredients mingled with water almost immediately. According to lead study author Tim McCoy, finding these ingredients with an environment of sodium-rich saltwater suggests Bennu held “the pathway to life.”
Together, these findings indicate that the requirements for life emerged much earlier and on a far wider scale than previously thought. This increases the odds that life has formed on other planets. As Galvin stated, “…asteroids like Bennu once acted like giant chemical factories in space and could have also delivered the raw ingredients for life to Earth and other bodies in our solar system.”
The success of the OSIRIS-REx expedition has blazed a path for future missions to collect samples from other cosmic bodies in our solar system. This includes missions to the dwarf planet Ceres, Jupiter’s moon Europa, and Saturn’s moon Enceladus. They are of high interest because they may harbor liquid water, and therefore, may also support the potential for life. “Are we alone?” McCoy asked. “That’s one of the questions we’re trying to answer.”