- How much lunar material did Apollo 11 bring back to Earth, and what has it revealed?
Solar System Formation
The origin and early evolution of the Sun and planets.
- Why does Uranus roll on its side with a rotation axis tilted 98 degrees to the ecliptic?
- Why was it thought impossible for planets to exist around a pulsar before this discovery?
- How might the planets around PSR B1257+12 have survived or formed after the supernova?
- Why did a gas giant orbiting so close to its star contradict existing models of planet formation?
- What is a 'hot Jupiter,' and how does migration explain its unusual orbit?
- What surprising minerals did scientists find in the returned comet dust, and what did they imply?
- Why does finding inner-solar-system minerals in an outer-solar-system comet challenge older formation models?
- Why did the discovery of a hot Jupiter around 51 Pegasi force astronomers to revise theories of planet formation?
- What is the Solar System Census, and why does its pace matter for planetary defense or discovery?