A stray SpaceX rocket and what scientists can learn
What can scientists learn from a stray SpaceX rocket hitting the Moon?
- Level
- B2
- Estimated time
- 30–40 minutes
- Reading
- 1 min read
The story
A stray SpaceX Falcon 9 upper stage is believed to have crashed into the Moon near the Einstein crater. The impact happened at around 07:35 BST and created a very brief flash and a plume of dust that may have reached 100km. Observatories in the Americas are analysing their data, and spacecraft such as Nasa's Lunar Reconnaissance Orbiter will take photos to compare before and after the crash.
The spent stage that hit the Moon was about the size of a five-storey building and weighed at least 4,000kg. It had been left drifting in a long, looping orbit and small pushes from the Earth, Moon, Sun and sunlight sent it slowly towards the lunar surface. The flash would have been hard for amateur astronomers to see, and even orbiting spacecraft were not in the right place to watch the impact live.
For planetary geologists this accidental collision is a rare, controlled experiment because researchers already know the rocket's size, speed and point of impact. That is a dream moment for planetary scientists because it lets them test models that predict how impacts dig out craters and throw debris. The results will help engineers design safer landers and give new clues about the Moon's geology and the Earth–Moon system from 4.5 billion years ago.
Key vocabulary
- rocket
- A vehicle or device that travels into space.
- crater
- A large round hole on the surface of the Moon made by an impact.
- impact
- The event of one object hitting another, often causing damage.
- orbit
- The path an object follows as it moves around a planet or moon.
- debris
- Pieces of rock, dust, or broken material thrown out by an impact.
- plume
- A cloud of dust or gas that rises after an impact.
- observatories
- Places with telescopes or instruments that observe space.
- geologists
- Scientists who study the structure and history of planets and moons.
Comprehension check
Write your answer, reveal the model answer, then score yourself honestly.
1. Where did the Falcon 9 upper stage hit the Moon?
2. What time did the impact happen?
3. What made the spent stage move towards the Moon?
4. Why is this collision useful for planetary geologists?
5. Which spacecraft will take photos to compare before and after the crash?
Grammar focus
Relative clauses (defining)
Defining relative clauses give essential information about a noun. They often begin with that or who and are required to identify the noun.
- The spent stage that hit the Moon was about the size of a five-storey building and weighed at least 4,000kg.
- That is a dream moment for planetary scientists because it lets them test models that predict how impacts dig out craters and throw debris.
Grammar exercise
Fill the gaps with a defining relative clause using the verb in brackets. Include 'that' when needed.
1. This is the stage ____ (weigh) at least 4,000kg, last year.
2. We saw the flash ____ (occur) at 07:35 BST, on Wednesday.
3. They will use images ____ (compare) before and after, today.
4. Engineers study craters ____ (throw) debris far, so far.
5. The rocket is a part ____ (drift) in a long orbit, recently.
Discussion
For reflection or speaking practice — not graded.
- How could better knowledge of debris and tremors change future Moon landers?
- Should countries track and manage spent rocket stages more carefully? Why or why not?
- What practical values do controlled experiments like this have for space exploration?
- Would you want to work on missions that study impacts on other planets? Why?