A discarded SpaceX Falcon 9 upper stage is expected to collide with the Moon on Aug. 5 [1].
The event transforms a piece of space debris into a scientific opportunity. Researchers intend to use the impact to study how craters form, and how lunar dust behaves during high-velocity collisions.
The rocket stage is traveling at approximately 5,400 mph [1], which is roughly 8,700 km/h [2]. This speed is roughly seven times the speed of sound. The resulting collision is estimated to release energy equivalent to about three tons of TNT [3].
Because the impact is unintentional, it provides a natural experiment for NASA and other agencies. The crash will create a visible plume of lunar dust and a new crater on the surface. This data may help scientists better understand the lunar environment, and improve the safety of future crewed missions to the Moon.
While some reports initially indicated the collision would occur on Wednesday, the confirmed date is Aug. 5 [1]. The discarded stage is a remnant of a previous launch, having drifted into a trajectory that made the impact inevitable.
Scientists are now preparing to observe the aftermath. The observation of the dust plume will provide insights into the Moon's surface composition, and the dynamics of impact events in a vacuum.
“The resulting collision is estimated to release energy equivalent to about three tons of TNT.”
This event highlights the growing issue of orbital debris and the unintended consequences of commercial spaceflight. However, by leveraging a 'dead' rocket as a kinetic impactor, scientists can gather empirical data on lunar geophysics without the cost of a dedicated mission. The results will likely inform the design of landing sites and shielding for future lunar habitats.
