Our Moon is unusually large for a small planet like Earth. Did it form from a single impact with a Mars-sized body, or did it form over time from multiple impacts?
The Last Eclipse
A solar eclipse is a rare event, and getting more rare all the time.
Cascade Effect
Orbital debris poses a risk to spacecraft, but it’s a risk we can manage.
Bang On
New evidence suggests Earth may have been formed from two worlds.
Is Earth Gaining Mass Or Losing Mass?
We generally think of the Earth as having a constant mass. On a basic level that’s true, but the Earth’s mass does change very slightly. So is it’s mass increasing or decreasing? The short answer is we don’t know.
Titan As An Earth-like World
There are many parallels between Titan and Earth, and so we can see the moon as a kind of colder, smaller cousin to our own planet.
Earth’s Oceans Have Always Been Local
Most of the worlds of the inner solar system are fairly dry. So how did Earth come to have large oceans on its surface?
The Potsdam Gravity Potato
The Earth has a spherical shape (technically an oblate spheriod) but it’s gravitational field is not as spherical.
Is the Earth Really Round?
Whaddya mean?! Of course the Earth is round. It’s so mind numbingly obvious that the Earth is round. It’s an idea we rarely question. But suppose a curious child asked you to prove it. Pointing at a globe or a photograph isn’t enough for this young scientist. She wants to discover that the Earth is round for herself.