SpaceX rocket crashes into Moon: Why the impact was nearly impossible to witness
The rocket's upper stage, travelling at around 5,400mph (8,700km/h), was expected to hit the Moon on Wednesday after spending about 18 months drifting through space.
A spent stage of a SpaceX Falcon 9 rocket is believed to have crashed into the Moon, creating a new crater near the Einstein crater. Scientists say the unexpected impact offers a rare chance to study how collisions affect the lunar surface and could help improve future Moon missions.
The rocket's upper stage, travelling at around 5,400mph (8,700km/h), was expected to hit the Moon on Wednesday after spending about 18 months drifting through space.
Why did the rocket hit the Moon?
The Falcon 9 rocket was launched from Florida in January last year, carrying two lunar landers into space. After successfully sending the landers towards the Moon, the rocket's upper stage had completed its task. The empty section, roughly the size of a five-storey building and weighing more than 4,000kg, was left in space.
Over the next 18 months, the combined gravitational pull of the Earth, Moon and Sun, along with pressure from sunlight, slowly changed its path. Astronomers tracking the object eventually realised it was heading towards the Moon and gaining speed.
Why was the impact difficult to see?
The rocket struck the Moon at around 07:35 BST (06:35 GMT) on Wednesday.
According to a report by BBC, although the collision created a brief flash, it lasted only a fraction of a second and happened on the side of the Moon that was in daylight. This made it almost impossible for amateur astronomers to see, even with powerful telescopes.
Scientists believe the crash may also have sent a dust plume stretching up to 100km (62 miles) above the lunar surface, but this too would have been extremely difficult to observe, the report further added.
Scientists are now analysing the impact
No spacecraft captured the collision live.
South Korea's Danuri lunar orbiter passed close to the impact site before the crash, and its team has said any images will only be released after researchers complete their analysis.
Meanwhile, NASA's Lunar Reconnaissance Orbiter is expected to photograph the crash site in the coming days. Scientists will compare images taken before and after the impact to study the newly formed crater.
Researchers using powerful telescopes in the Americas are also analysing data collected during the event. Processing these observations could take days or even weeks.
Why is this crash important?
According to BBC, scientists describe the impact as a rare natural experiment.
Because they know the rocket's exact size, weight, speed and impact location, researchers can compare the results with computer models that predict how craters form.
The data could improve understanding of:
How craters are created on the Moon.
How far rocks and dust are thrown after an impact.
How shock waves travel through the Moon's surface.
This information could help engineers design safer lunar landers and future Moon bases by showing how far debris can travel and how much the ground shakes after an impact.
Material exposed from beneath the lunar surface may also provide new clues about the Moon's geology and the formation of the Earth-Moon system around 4.5 billion years ago.