Planetary Motion

Orbits happen because of gravity and something called momentum. The Moon's momentum wants to carry it off into space in a straight line. The Earth's gravity pulls the Moon back towards the Earth. The constant tug of war between these forces creates a curved path. The Moon orbits the Earth because the gravity and momentum balance out.

Maria was born in Nantucket, USA. Her family made sure that all 10 of their children were well-educated, the girls and the boys. Maria also read about lots of topics in the local library, where her mother worked. Her father was a teacher and his hobby was astronomy.