Cradle of Life As We Know It
Earth is the only place we know of in the universe that harbors life. Ours is the largest terrestrial planet in the solar system. Our rocky, volcanic world is coated in a thin veneer of liquid water, living things, and translucent atmosphere, whose complicated interactions make Earth's surface into a place of constant change. We humans have only had fifty years of perspective on Earth as a planet, of seeing it as a "pale blue dot" floating in the black vacuum of space.
With that perspective, we know precious and unique our planet is. We know, too, that we are having measurable effects on the complex interactions of ocean, land, life, water, and air, changing our climate. But predicting the future of our climate is hard. Understanding how Earth's systems work by studying the way they operate on other worlds is a major goal of planetary exploration. Mars, Venus, and Titan all have (or had) active geology, hydrology, and weather -- but, as far as we know, they don't have life. Is Earth really that unique? Are we truly alone in the universe? We won't know unless we keep searching.
News from Earth
The Deep Space Climate Observatory (DSCOVR) has begun sending us fresh, whole-hemisphere images of our own fragile planet. Some sources say that the spacecraft is "orbiting" the L1 point. Dave Doody thinks this warrants some scrutiny.
Earth's Place in Space
The Planetary Fund
Help us accelerate progress in our four core enterprises: Robotic Space Exploration, Human Space Exploration, Planetary Defense, and The Search for Life.