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
Two images of Earth taken from different spacecraft at the same time illustrate differences in "true" color imaging among spacecraft.
It's fun to watch the seasons shift from space, and as of this year we have new ways to do that.
I just love photos of Earth from planetary missions -- especially if they manage to get Earth and Moon in the same shot, as Hayabusa2 did on November 26.
Earth's Place in Space
Beyond The Horizon, There's More To Explore!
Become a member of The Planetary Society and together we will create the future of space exploration.