The upper atmosphere is the thermosphere, extending from 56 miles to 375 miles above Earth. It is very hot but has low air density. The exosphere, which merges with space, has even lower air density and is home to auroras. The upper atmosphere is generally considered to be the region of the thermosphere, which is […]
Earth has had three different atmospheres. The first was mostly hydrogen and helium, but it dissipated due to the heat of the molten crust and solar wind. The second was mainly carbon dioxide and water vapor, similar to Venus, and was 100 times denser than today. The third atmosphere was formed by cyanobacteria, which converted […]
Most electromagnetic radiation is absorbed by the Earth’s atmosphere, including harmful X-rays, gamma rays, and ultraviolet light. Visible light is one of the most important categories not absorbed, allowing for organisms to develop sensory organs tuned to it. Radio waves easily pass through the atmosphere, allowing for radio technology and observatories. The vast majority of […]
Thousands of tonnes of space debris hit Earth each year, but most is in the form of dust. Large asteroids that could threaten Earth are rare. Asteroids and meteorites are different, and the largest asteroids are Ceres, Pallas, and Vesta. Asteroids enter Earth’s atmosphere every day, but rarely make it to the surface because they […]
Venus has a dense atmosphere of 96.5% carbon dioxide and 3.5% nitrogen, causing extreme global warming with an average surface temperature of 461.85°C. Balloons filled with breathable air could float at 50-65 km above the surface, making it the most habitable region in the solar system outside of Earth. Venus lacks its own magnetic field […]
