The first of the two-part series, titled "From Space," explores the birth and early life of Earth, as seen from orbit, using clues from over 300 satellites and space stations surveying Earth’s landmarks to work backwards and piece together what the planet’s early days might have looked like.
2019 • Astronomy
We don't yet know where the edge of the universe is or what happens there; but thanks to cutting-edge technology and new discoveries, experts might finally reveal the secrets of the phenomena that can be found in deepest reaches of the cosmos.
Today Phil helps keep you from ticking off an astronomer in your life by making sure you know the difference between a meteor, meteorite, and meteoroid. When the Earth plows through the stream emitted by a comet we get a meteor shower. Meteors burn up about 100 km above the Earth, but some survive to hit the ground. Most of these meteorites are rocky, some are metallic, and a few are a mix of the two. Very big meteorites can be a very big problem, but there are plans in the works to prevent us from going the way of the dinosaurs.
Massive stars fuse heavier elements in their cores than lower mass stars. This leads to the creation of heavier elements up to iron. Iron robs critical energy from the core, causing it to collapse. The shock wave, together with a huge swarm of neutrinos, blast through the star’s outer layers, causing it to explode. The resulting supernova creates even more heavy elements, scattering them through space. Also, happily, we’re in no danger from a nearby supernova.
Look up at the night sky, and you see countless shining stars. Our galaxy has 100 billion of them. Astronomers are now hunting for clues that will reveal "the first star" that transformed the ancient universe and led to the creation of everything that followed: galaxies, planets and life itself.