Long ago 4.5 billion years ago, right after the Earth formed our planet was hot. It formed by essentially getting slammed billions of times by asteroids, and all that energy of impact was enough to keep the Earth broiling.
Eventually heavy elements like iron and nickel sank to the core, and lighter ones rose to the surface. This differentiation created the Earth we see today: An inner, solid nickel/iron core that's nearly as hot as the surface of the Sun; an outer, liquid iron core; the solid, rocky mantle; and the thin crust topping it off.
In Otherlands, palaeobiologist Thomas Halliday uses a mix of science and imagination to show us the weird and wonderful landscapes and life forms of the early Earth
Physicists know a lot about the most fundamental properties of the universe, but they certainly don’t know everything. 2021 was a big year for physics – what was learned and.
Sixty-six million years ago, the dinosaurs had a really bad day.
Not just them, either, since 75% of the species on Earth disappeared in a short time. There’s no doubt now that the main driver of this mass murder, called the K-Pg extinction event, was an enormous asteroid (or possibly comet) impact, an object 10 kilometers across that slammed into the planet just off the coast of modern-day Yucatan. This created a crater some 150 kilometers wide, and instigated a series of catastrophic events both immediate and long-term that wiped out most of the life on Earth.