Potassium argon is a radiometric dating method that involves
The Scale of the Universe from Big to Small (youtube) The Scale of the Universe from Small to Big (youtube) NASA Astronomy Picture of the Day (APOD) The Scale of the Universe - Interactive (manual control scale) Sizes (nano) Stars and Galaxies started to form.Reionization marks the point at which the hydrogen in the Universe became ionized.Cretaceous–Paleogene Extinction Event is also known as the Cretaceous–Tertiary (K–T) extinction, was a mass extinction of some three-quarters of the plant and animal species on Earth that occurred over a geologically short period of time approximately 66 million years ago.With the exception of some ectothermic species like the leatherback sea turtle and crocodiles, no tetrapods weighing more than 25 kilograms (55 lb) survived.- Galaxies - Space - Black Holes - Earth - Planets - Moon - Stars - Sun - Solar System Magnetics - Gravity Extra Terrestrial - ET - Space Aliens - Probes Space Station - Space Shuttle - Space Travel Satellites - Asteroids - Telescopes Time Measuring Pyramid of Complexity Science - Physics The photo on the right is not a Selfie.It is just an Artist rendition of what our galaxy would look like from another galaxy.Marine Biology , in the late Proterozoic, oxygen levels in the oceans and atmosphere increased dramatically.By 600 million years ago, the oxygen in the atmosphere reached about one-fifth of today’s level (21 percent).
Shape of the Universe - Photo GN-z11 high-redshift galaxy found in the constellation Ursa Major, and is currently the oldest and most distant known galaxy in the observable universe - 13.4 billion years old. Mostly Molten Rock Theia collided with another planetary-mass object, Gaia (the early Earth) around 4.51 billion years ago. New type of Green Algae produced O2, which created the Ozone Layer that protected life from damaging UV Rays and gave life a chance to progress.Gondwana is the name given to an ancient supercontinent.It is believed to have sutured between about 570 and 510 million years ago (Mya), joining East Gondwana to West Gondwana.Records of the appearance and disappearance of particular taxa at a single locality are insufficient to define a bioevent.Late Devonian Extinction was one of five major extinction events in the history of the Earth's biota.