Click on a Planet Diary category for links to up-to-date information for further exploration or research.
Thousands of years ago, people began studying the movements of the planets and stars and wondered how our planet fit into the scheme of things. In modern times, we don't just watch the heavens. We explore them. With the help of high-powered space telescopes, space shuttles, orbiting space stations, and traveling space probes, we have learned about the far reaches of this galaxy and beyond. When astronomical events and human endeavors reveal new information about the universe, Planet Diary will cover them.
The gases surrounding our planet allow us to breathe, shield us from ultraviolet rays, and keep us warm. The atmosphere is the theater where dramatic weather events such as hurricanes and tornadoes take place. It's also where much of our pollution ends up. Human activities like burning fossil fuels and cutting down trees have increased greenhouse gases in the atmosphere to levels not seen in thousands of years. Planet Diary keeps a watchful eye on events that make pollution and global warming worse, and applauds efforts to make them better.
The biosphere is the ecosystem linking all other ecosystems on the planet. This layer includes millions of species of animals, plants, and microbes found in every nook and cranny of the land, oceans, and air. Microbes have been found 40 kilometers high in the atmosphere, more than 5 km beneath Earth's crust, and 10 km below the sea. The fate of all living things in the biosphere hangs on the actions of a single species, Homo sapiens. We humans. Planet Diary tracks the health of the biosphere and efforts to protect it.
Water covers three-fourths of the surface of our "Blue Marble." The water cycle keeps it moving from the air to the ground and back again. Too much water coming down too soon can trigger floods, while not enough of it for too long brings drought. while most of the hydrosphere's water is found in the oceans, it's also in lakes, rivers, streams, aquifers, and even puddles and cracks in rocks. Wherever its found, much of our precious "liquid gold" has been polluted by runoff from cities, farms, and factories. Planet Diary chronicles the battle to restore our oceans and waterways to good health.
The planet's layer known as the geosphere is made up of the rock in its crust. Tectonic forces inside Earth build mountains and keep rocks changing form in the rock cycle. While the surface of the geosphere is sculpted slowly over millions of years by wind and water, volcanoes can suddenly belch out new rock in fiery streams of lava. Earthquakes rearrange rock layers in violent bursts. Planet Diary tracks these changes in Earth's rocky skin.
The word cryosphere comes from the Greek word cryos meaning "cold" or "ice." It includes the part of the planet's surface covered in snow or ice, including glaciers, ice caps, ice sheets, and sea ice. These days, much of the planet's cryosphere has come under threat from rising temperatures. Planet Diary tracks this global meltdown and reports on efforts to slow it down.