Near-Earth asteroid Bennu is an active space rock

The first-ever close-up observations of particle plumes erupting from an asteroid’s surface.

This view of asteroid Bennu ejecting particles from its surface on January 19 was created by combining two images taken on board NASA’s OSIRIS-REx spacecraft. Other image processing techniques were also applied, such as cropping and adjusting the brightness and contrast of each image. Credits: NASA/Goddard/University of Arizona/Lockheed Martin
This view of asteroid Bennu ejecting particles from its surface on January 19 was created by combining two images taken on board NASA’s OSIRIS-REx spacecraft. Other image processing techniques were also applied, such as cropping and adjusting the brightness and contrast of each image. Credits: NASA/Goddard/University of Arizona/Lockheed Martin

Bennu is close to Earth, it’s really old and well-preserved. It might even help us in our search for clues to the origins of life, thus, it is the target of the OSIRIS-REx mission which is intended to return samples to Earth in 2023 for further study.

On 3 December 2018, the OSIRIS-REx spacecraft arrived at Bennu after a two-year journey. According to NASA, the spacecraft has made its first ever close observation of particle plumes erupting from an asteroid’s surface. In addition, the discovery has found that the asteroid has more rugged terrain than expected.

Dante Lauretta, OSIRIS-REx principal investigator at the University of Arizona, Tucson said, “The discovery of plumes is one of the biggest surprises of my scientific career. And the rugged terrain went against all of our predictions. Bennu is already surprising us, and our exciting journey there is just getting started.”

The team originally discovered the particle plumes on Jan.6 while the spacecraft was orbiting Bennu at a distance of about one mile (1.61 kilometers). Then, in a very short time, the team increased the frequency of observations and subsequently detected additional particle plumes during the following two months. It becomes clearer that many of the particles were ejected from the Bennu. The team even tracked some of the particles that orbited Bennu before returning to the asteroid’s surface.

Following a safety assessment, the mission team concluded the particles did not pose a risk to the spacecraft. The team continues to analyze the particle plumes and their possible causes.

Lori Glaze, acting director of the Planetary Science Division at NASA Headquarters in Washington said, “The first three months of Bennu to learn about the origin of the solar system. OSIRIS-REx’s sample will help us answer some of the biggest questions about where we come from.”

The main goal of exploring Bennu is to get detail insights about the origins of our solar system, the sources of water and organic molecules on Earth, the resources in near-Earth space as well as asteroids that could impact Earth.

Analysis of this pristine cosmic dirt and gravel will help scientists better understand the solar system’s early days. It could also help reveal the role that dark, carbon-rich asteroids like Bennu may have played in delivering water and the chemical building blocks of life to our planet.