What’s the sun made of? – Astronomy – Science
The sun from space The Sun is a star, just like billions of other stars in the universe. Our Sun probably formed a little more than four and a half billion years [...]
The sun from space The Sun is a star, just like billions of other stars in the universe. Our Sun probably formed a little more than four and a half billion years [...]
Lyrid meteor shower What is a meteor? Meteors or meteorites are bits of rock (like granite) and ice - usually a mixture of rock and iron and nickel but sometimes just rock or [...]
A dinosaur skeleton from the Jurassic period How the Jurassic period began When the Jurassic period began, about 199 million years ago, a lot of animals had just become extinct [...]
Volcano erupting When was the Cretaceous period? During the Cretaceous period, beginning about 145 million years ago, the continents continued to drift away from each other. Plate tectonics Back to [...]
A pile of chestnuts When did chestnuts evolve? Chestnut trees are related to oak trees, and like oak trees they probably evolved early, around 66 million years ago, around the [...]
Boa Constrictor snake Some kinds of amphibians evolved into reptiles about 300 million years ago. At this time, plate tectonics had moved more and more of the land on Earth into [...]
A dinosaur skeleton: evolution of dinosaurs When did dinosaurs evolve? The first dinosaurs evolved out of earlier types of chordate reptiles about 230 million years ago, on the big land [...]
Rat from New Zealand - Evolution of mammals When did the first mammals evolve? About 200 million years ago, when all the land on Earth was stuck together in one [...]
Chordates include this giraffe from Kenya What is a chordate? Any animal that has a spinal cord is a chordate. This group covers most of the creatures you see at [...]
A robin sits on a branch: birds biology When did birds evolve? The first birds evolved out of earlier small dinosaurs late in the Jurassic period, about 150 million years [...]