The vast universe holds all of humanity’s imaginations of the unknown, and those with a strong thirst for knowledge will pursue that curiosity and look toward the endless night sky in the hopes of getting closer to the truth about the universe’s origins in the unknown.
On September 25, NASA successfully completed its seven-year mission to collect samples from the first asteroid in the United States. The space capsule containing hundreds of grams of material from the asteroid Bennu traveled 1.9 billion kilometers through space and finally “came home” at 10:00 AM on September 25, US time.
After the successful retrieval by researchers, the sample capsule will be transported by helicopter to a temporary laboratory for the removal of its primary components. Following removal, the asteroid material will undergo a process known as “Nitrogen Purge” – Nitrogen can effectively protect the samples from Earth’s material contamination.
Eventually, the samples will be sent to the Johnson Space Center in Texas, where they will undergo formal analysis by researchers.
Formed from a loose collection of rocks, much like a pile of rubble, Bennu has a width of only 500 meters, making it very small compared to the Chicxulub asteroid that impacted Earth about 66 million years ago, leading to the extinction of the dinosaurs. Photo: Sci.news
The mission to retrieve samples from the asteroid Bennu began seven years ago. In 2016, the OSIRIS-REx mission was launched. The Atlas V rocket successfully launched the OSIRIS-REx spacecraft into space, officially commencing the 7-year space adventure of OSIRIS-REx. After entering space, OSIRIS-REx circled the Sun for a year.
In the following year, 2017, OSIRIS-REx once again approached Earth, with the goal not to “return home.” OSIRIS-REx still had six more years to complete its journey. The purpose of approaching Earth was to use Earth’s gravitational force to adjust its trajectory in space and gain speed.
In 2018, with the support of the OSIRIS-REx engineering team, the spacecraft successfully approached its “dream lover,” with the distance between OSIRIS-REx and the asteroid Bennu being only 20 kilometers, a very short distance – this distance signified that OSIRIS-REx had successfully approached and could touch Bennu at any time.
The asteroid Bennu is located approximately 6.2 billion kilometers from Earth. Samples were collected from this asteroid in 2020 and have been stored in the probe’s container ever since. Photo: NASA
At this point, the OSIRIS-REx mission could finally move on to the next phase. During this phase, OSIRIS-REx would accompany the asteroid Bennu for two years. Researchers used this time to map the surface of the asteroid Bennu from images sent back by OSIRIS-REx to analyze the best sampling locations. At the same time, researchers could also conduct preliminary studies on Bennu and learn as much as possible about this asteroid.
Finally, in 2020, the OSIRIS-REx spacecraft touched down on the asteroid Bennu and successfully collected hundreds of grams of material from it. The sampling process was even more successful than anticipated – OSIRIS-REx collected an excessive amount of samples, so it couldn’t be sealed successfully.
Based on the results, the sample collection mission was a success, and OSIRIS-REx officially began its journey back in 2021, successfully “delivering” the samples on September 25th.
Why did NASA spend so much time studying the asteroid Bennu and take seven years just to find “rocks” from it? Asteroid Bennu was discovered by the Lincoln Near-Earth Asteroid Research (LINEAR) Institute on September 11, 1999. What makes it unique is not that it comes near Earth every six years or that it might collide with Earth in 2182. What’s truly unique is its “age.”
Scientists are currently inferring the age of the Solar System by determining the ages of the meteorites that have impacted Earth. However, due to factors such as material erosion on Earth, the information preserved on meteorites would be damaged to varying degrees. The oldest rocks found on Earth have an age of approximately 4 billion years. Bennu, on the other hand, is 4.5 billion years old, 500 million years older than the oldest rocks on Earth.
Because Bennu has traveled through space, it hasn’t been contaminated by any foreign materials. In plain terms, Bennu is a “time capsule” well-preserved within the early Solar System. Scientists hope to discover the origins of life, the origins of Earth, and even the origins of the Solar System through the study of the asteroid Bennu.
The journey of the OSIRIS-REx spacecraft will continue in the future. OSIRIS-REx has been officially renamed OSIRIS-REx APEX and will continue researching a new target – the asteroid Apophis, one of the most famous asteroids in the Solar System. OSIRIS-REx APEX is expected to encounter this asteroid in the coming years and conduct more scientific observations.