Astronomy Picture of the Day

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

May 30, 1998

Water World
Credit: STS-45 Crew, NASA

Explanation: Water (Dihydrogen Oxide, H2O) is a truly remarkable chemical compound, fundamental to life on Earth. Earth is the only planet in the Solar System where the present surface temperature and pressure allow the three forms of water, solid (ice), liquid (ocean), and gas (water vapour condensing in clouds) to exist simultaneously. Water in one of these forms accounts for everything visible in this view of Earth from space looking north at the Bering Sea and the coast of Alaska, USA, around Bristol Bay.

Tomorrow's picture: Phobos

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Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (USRA)
NASA Technical Rep.: Jay Norris. Specific rights apply.
A service of: LHEA at NASA/ GSFC
&: Michigan Tech. U.