Solar System
Kepler’s Third Law
[/caption] "The square of the orbital period of a planet is proportional to the cube of the semi-major axis of…
Earth’s Circumference
The Earth's circumference - the distance around the equator - is 40,075 kilometers around. That's sounded nice and simple, but…
When Was Mars Discovered?
[/caption] It is impossible to know the answer to ''when was Mars discovered''. It is bright enough to be seen…
Exploration of Mercury
[/caption] As one of the planets visible with the unaided eye, Mercury has been known before recorded history. But until…
List of Planets
Mercury is the closest planet to the Sun but not the hottest. That distinction goes to Venus. The planet was…
How Many Stars are There in the Milky Way?
The Milky Way Galaxy, our little corner of the Universe, is a pretty massive place, with an estimated 200-400 million…
What are Saturn’s Rings Made Of?
Saturn is sometimes called the ''Jewel of the Solar System'' because its ring system looks like a crown. The rings…