A discarded SpaceX rocket stage is expected to collide with the Moon next week, giving scientists a rare opportunity to study how a human-made object behaves when it strikes the lunar surface.
The Falcon 9 upper stage is projected to hit the Moon on August 5, following its journey through space after completing its original mission. Unlike a controlled lunar landing, the upcoming collision is expected to occur at high speed, creating an impact that researchers will be watching closely.
Scientists do not yet know precisely what the collision will produce. The impact could excavate lunar soil and rock, sending debris and other material above the surface. Observations of the resulting plume could provide researchers with information about the composition and structure of the lunar terrain at the impact site.
Such an event could also help scientists understand the consequences of objects striking the Moon without an atmosphere to slow them down. Unlike Earth, the Moon has no substantial atmosphere, meaning an incoming spacecraft or rocket stage can hit its surface at tremendous speed.
The planned collision is attracting attention partly because it offers an unplanned experiment on the lunar environment. Scientists can compare the event with previous artificial and natural impacts and examine how much material is thrown from the surface.
