The mission to sample Bennu has both scientific and planetary defense purposes. Scientists hope to gain insight into the early solar system by studying rocks from Bennu that date back 4 billion years. The molecular composition of the samples could provide clues about the origins of life on Earth. Additionally, Bennu's orbit crosses Earth's, and there is a small chance it could collide with our planet in the future. By studying Bennu's composition, NASA aims to better understand potentially hazardous near-Earth objects and develop strategies to divert them if necessary.
While Bennu is not the largest asteroid, its problematic orbit makes it a priority for monitoring. According to calculations, there is a roughly 1 in 2,700 chance of Bennu impacting Earth in 2182. However, this probability will be further refined after Bennu's close pass by Earth in 2135.
Bennu has a diameter of 500 meters (about 1,640 feet), significantly smaller than the asteroid that caused the extinction of dinosaurs. Nevertheless, an impact from Bennu would have significant consequences.
The OSIRIS-REx spacecraft collected a sample of Bennu's surface using a sampler device at the end of a robotic arm. The device plunged about 20 inches deep into the asteroid's surface and retrieved regolith, a mixture of material. The exact amount of material collected is unknown, but it is estimated to be around 250 grams (8.8 ounces), with a margin of error of 101 grams. The mission's goal is to have at least 60 grams of material in the capsule.
Is the OSIRIS-REx mission officially considered a success? This mission was a remarkable achievement in aerospace engineering, as it involved guiding a spacecraft to orbit a small object millions of miles away. Due to the complexities of the task, the spacecraft had to operate autonomously during the delicate sampling operation on the asteroid's rough surface. Initially, it was unknown that the asteroid was a loosely aggregated "rubble pile." The success of the mission will ultimately be determined by the scientific discoveries made from studying the collected samples in the laboratory.
What is a fascinating word used by scientists who study asteroids and planets? One interesting term used by scientists in this field is "ephemeris," which NASA defines as a tabulation of computed positions and velocities of an orbiting body at specific times. The plural form of this word is "ephemerides."
Why is the mission called OSIRIS-REx? The mission is named OSIRIS-REx because the acronym is easier to pronounce than its full name, which is Origins, Spectral Interpretation, Resource Identification, Security-Regolith Explorer. The name "Osiris" comes from an ancient Egyptian god, and Dante Lauretta, the lead scientist of the mission, who has an interest in mythology, believed it would be a suitable name. Recently, with the new target, the spacecraft has been renamed OSIRIS-APEX, standing for OSIRIS-Apophis Explorer.