NASA’s OSIRIS-REx spacecraft recently made some groundbreaking revelations about the asteroid Bennu. After a two-year expedition which began in December 2018, the spacecraft has uncovered that Bennu has an abundance of accessible water. This mission took off from Cape Canaveral, Florida on September 8, 2016 and it aims to research, collect samples from the asteroid and return to Earth in 2023.
Other Noteworthy Asteroid Missions
Although the OSIRIS-REx mission is a significant exploration, it isn’t the first to visit an asteroid or attempt a sample return. The honor of the first successful sample return mission goes to Japan’s Hayabusa Mission. Europe has also contributed notably to the field through the Rosetta Mission.
The Rosetta Mission was initiated by the European Space Agency in 2004 to explore Comet 67P/Churyumov-Gerasimenko and its surroundings. Remarkably, this was the first mission to orbit a comet’s nucleus and successfully land a probe on the surface. As well as flying alongside a comet as it approached the inner Solar System.
The Purpose of OSIRIS-REx Mission
The name OSIRIS-REx stands for Origins, Spectral Interpretation, Resource Identification, Security-Regolith Explorer, which succinctly summarizes the objectives of this mission:
– ‘Origins’: It aims to return and analyze a pristine carbon-rich asteroid sample.
– ‘Spectral Interpretation’: The goal is to provide ground truth or actual observations for telescopic data of the entire asteroid population.
– ‘Resource Identification’: It maps the chemistry and mineralogy of a primitive carbon-rich asteroid.
– ‘Security’: This entails measuring the Yarkovsky effect, or the slight push created when an asteroid absorbs sunlight and re-emits it as heat, which could alter its trajectory.
– ‘Regolith Explorer’: This involves documenting the regolith or loose, outer material at the sampling site, right down to the sub-centimeter scale.
The Importance of this Mission
The OSIRIS-REx mission plays a vital role in understanding the origins of our Solar System. As Earth formed, objects like Bennu might have delivered molecules of carbon and water to our planet. By examining Bennu, we could gain a deeper understanding of how life originated on Earth.
This research also has significant implications for planetary protection as Bennu is one of the most potentially hazardous asteroids currently known to Earth. The asteroid has 1‐in‐2,700 chance of impacting Earth in the late 22nd century. Close surveillance by OSIRIS-REx will provide crucial information about Bennu’s path and help scientists devise strategies against hazardous asteroids.
Implications for Future Space Exploration
The discovery of water on Bennu could open up opportunities for using asteroids as refueling stations for spacecraft on the way to deeper destinations in space. Since water can be divided into hydrogen and oxygen, it could be used as rocket fuel. Harvested water could also be utilized to supply astronauts. Furthermore, asteroids contain a range of valuable minerals, indicating the possibility of asteroid mining in the future.
| Date Discovered | Name | Size | Composition |
|---|---|---|---|
| September 11, 1999 | Bennu (originally named 1999 RQ36) | 500-meter wide asteroid | A large amount of carbon |
A Primer on Bennu
Bennu, discovered by the Lincoln Near-Earth Asteroid Research (LINEAR) survey on September 11, 1999, was initially named as ‘1999 RQ36’. Its current name is derived from an Egyptian deity associated with the Sun, often depicted as a gray heron. Bennu is a 500-meter wide asteroid in an elliptical orbit around the sun, primarily composed of carbon.
Why Bennu?
Proximity to Earth and appropriate size make Bennu a fitting choice for this mission. Bennu’s orbit is in close proximity to Earth’s, even crossing it, and the asteroid makes its closest approach to Earth every six years. Also, unlike smaller asteroids which spin very rapidly making sampling difficult, Bennu’s size makes it approachable and landing feasible.