Realm of the Giants
The solar system’s outer realm contains four giant planets. The largest is Jupiter, at about 11 times Earth’s diameter. Despite […]
Exploring Our Own Back Yard
The structures of the terrestrial planets are similar. Each planet has a layered structure that developed through a process called
Why is the Moon covered with craters?
Perhaps a better question might be why isn’t Earth covered with craters? Both Earth and Moon — and the other
What is the chance of Earth being hit by a comet or asteroid?
Not much in our lifetimes — perhaps 1 in 10,000 — but over thousands or millions of years, major impacts
What is the chance of Earth being hit by a comet or asteroid? Read More »
Did an asteroid really kill the dinosaurs?
The truth behind the demise of the dinosaurs may never be fully resolved, but a growing body of evidence has
What is the biggest moon in the solar system?
That is a tricky question, which astronomers didn’t answer correctly until fairly recently. For a while, they thought the biggest
Orion, the Hunter
Two of the brightest stars in the evening sky lie at opposite corners of the rectangle: bright orange-red Betelgeuse at
Gemini, the Twins
Many cultures have seen two humans in this star pattern, which consists of two roughly parallel lines of stars capped
Canis Major, the Great Dog
The brightest star in Canis Major also is the brightest in the entire night sky — brilliant Sirius, which is
Auriga, the Charioteer
The constellation has an uncertain origin. It might represent Neptune rising from the sea in a chariot. Or it might