In the early 2000s, a team of planetary scientists at NASA began planning something audacious. They would build a spacecraft. Aim it at an asteroid. Launch it across more than a billion miles of space. Map the asteroid's rugged terrain at an unprecedented, centimeter-level resolution. Hover over the surface to collect a sample. And then bring it all the way home.
The mission was called OSIRIS-REx. The target was Bennu. And one of the destinations was Lawrence Livermore National Laboratory (LLNL).
In the latest episode of the Big Ideas Lab, learn how just 122 grams of material from the asteroid Bennu is revealing clues from the earliest moments of the solar system. Listen on Apple or Spotify.
The question driving the OSIRIS-Rex mission is one that humanity has asked since its inception.
"The genesis of this mission was that curiosity of where we came from, where the ingredients in our solar system came from and what they were," said LLNL scientist Greg Brennecka. "One of the ways to do that is to look at samples that formed in the early solar system and analyze them and figure out when it happened, where it happened and what it's made from."
LLNL is one of many institutions to receive a portion of the Bennu sample.
"We are world experts here at the Lab in analyzing very small samples with very advanced analytical tools. And that specifically is related to the ability to measure isotopes in these rocks using mass spectrometers," said LLNL scientist Thomas Kruijer. "These isotopes then in turn tell you about where the material formed, how it formed and when it formed."
With these measurements, the researchers revealed that the composition of Bennu is very similar to that of the sun. Other teams working with the sample found chemistry that is relevant for life, including amino acids, nucleotide bases for DNA and RNA and sugar backbones.
While images of an asteroid can provide valuable information, Brennecka emphasized the importance of having a real sample.
"If somebody sends you a picture of a birthday cake, you can kind of tell what that birthday cake is made of. You may have an idea about what it tastes like, but you don't really know," he said. "We can take pictures of a lot of asteroids. We can have ideas about what they're made from. But you don't really know until you have that birthday cake in front of you and you can taste it."
The team at LLNL continues to study the Bennu sample and aims to expand their capabilities to do the same for retrievals from the Artemis lunar missions.
"You cannot simulate or compute your way to a discovery. You need to actually measure these samples," said Kruijer. "I think that's very important to realize that this is an empirical science. We do measurements and that will continue to remain important."
Listen to the latest episode of Big Ideas Lab on Apple or Spotify.
