OSIRIS-REx rover had landed on the asteroid Bennu back in December 2018. It had then found an unusual event happening on Bennu. The asteroid was found to cast out particles into space. The rover’s navigation camera was found to spot the particles and the researchers had thought of it as stars in the backdrop. It is just after a detailed study that the scientists found it to be particles of rock that may, later on, pose trouble. The asteroids are termed active asteroids or main-belt comets only after they are found to be losing mass. In certain cases, they are known to leave behind short-lived trails of dust and debris that appear like the tail of a comet.
The trails were thought to be made of melting ice but now it is clear that there are several mechanisms that are causing the asteroid to be active. The ejection of particles can be clearly seen through the telescopes. As per the Earth-based observations, the asteroids appeared stable and even Bennu appeared inactive. But, OSIRIS-Rex surprised the researchers by showing them Bennu’s particle ejection activity. The sublimating ice, impacts, rotational instability, thermal fractures, and electrostatic repulsion could have possibly made the asteroid release particles. The ejection of 200 particles was spotted on January 6, 2019, and they were found to have traveled 3 meters per second followed by another ejection on February 11, 2019. The particles were found to orbit for a certain period of time before falling onto the surface or being ejected deep into space. The reason for the ejection of particles is still being validated.
In a similar context, NASA has decided to buy more Earth observation data that are collected by commercial satellite constellations at the beginning of a pilot program. NASA is working toward collecting an enormous amount of data from Maxar and Planet satellites after finding the information to be of enough quality and utility. The Spire Global data is also being evaluated by the space agency. NASA had planned to purchase Earth science data from Maxar, Planet, and Spire back in 2018, but it is just being initiated. The key plan is to develop a process to add more vendors into the Commercial Smallsat Data Acquisition program in the coming years.