Asteroid Bennu: A Cosmic Grocery Store for Life's Ingredients

Asteroids might have been like cosmic delivery trucks, bringing essential supplies for life to Earth. Scientists recently found tryptophan, an important amino acid, in samples from asteroid Bennu. This discovery adds to the growing list of life's building blocks found in space rocks. Bennu is a small asteroid that visits Earth every six years. In 2020, NASA's OSIRIS-REx mission collected samples from Bennu and brought them back to Earth in 2023. These samples are like a time capsule, showing what the early solar system was like. Before this, scientists had already found 14 out of 20 amino acids that living things on Earth use in Bennu's samples. They also found all five biological nucleobases, which are the letters that make up DNA and RNA. Now, with the discovery of tryptophan, that number has increased to 15. Tryptophan is special because it's one of the more complex amino acids. Until now, scientists had never found it in any space samples or meteorites. Its presence in Bennu supports the idea that life's ingredients might have been made in space before Earth even existed. Bennu is about one-third of a mile wide and is thought to have broken off from a larger asteroid between 2 billion and 700 million years ago. It formed in the main asteroid belt between Mars and Jupiter and has been orbiting close to Earth for about 1. 75 million years. The material that makes up Bennu came from supernovas, which are explosions of old stars. These explosions created the elements found in the asteroid. Bennu has also been found to contain ammonia, which can help form molecules like amino acids, as well as different types of minerals. Scientists believe that asteroids like Bennu could have delivered these essential ingredients to Earth early on, making it easier for life to start. However, more tests are needed to confirm the presence of tryptophan in the Bennu samples. The discovery of tryptophan in Bennu is a big deal because it shows that many of the building blocks of life can be produced naturally within asteroids or comets. This finding expands the list of amino acids that are produced in space and could have been delivered to Earth.