Earth-Save

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Terra is the flagship satellite of NASA’s Earth Observing System, a series of satellites gazing down on our planet from the unique vantage point of space.  Focused on measurements important for U.S. and international scientists, Terra helps research how Earth’s lands, oceans, air, ice and life function together as an environmental system.

This photo of our planet was taken by the Earth Observing System flagship Terra.  This spectacular "blue marble" was the most detailed true-color image of the entire Earth to date.  Using a collection of satellite-based observations, scientists and visualizers stitched together months of observations of the land surface, oceans, sea ice and clouds into a seamless true-color mosaic of every square kilometer of our planet.

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Earth is a planet on which we humans live.  Earth is the third planet from the Sun.  Earth orbits the Sun once every (approximately) 366.26 days, where a day is the time it takes for Earth to rotate once on its axis.

Home to millions of species, including humans, Earth is the only place in the universe where life is known by humans to exist.  Earth formed 4.54 billion years ago, and life appeared on its surface within a billion years.  Earth is expected to support life for another 1.5 billion years, after which the Sun will brighten and eliminate the biosphere.

Earth’s outer surface is divided into several rigid plates that migrate gradually across the surface over millions of years.  About 71% of Earth’s surface is covered with salt-water oceans, the rest consisting of continents and islands.  Liquid water, necessary for all known life, is not known by humans to exist on any other planet in the universe.  Earth’s interior remains geologically active, with a thick layer of relatively solid mantle, a liquid outer core that generates a magnetic field, and a solid iron inner core.

Adapted from Wikipedia