An ocean planet, ocean world, water world, aquaplanet or panthalassic planet is a type of terrestrial planet that contains a substantial amount of water either at its surface or subsurface.
Earth is the only astronomical object known to have bodies of liquid water on its surface, although several exoplanets have been found with the right conditions to support liquid water. For exoplanets, current technology cannot directly observe liquid surface water, so atmospheric water vapor may be used as a proxy. The characteristics of ocean worlds—or ocean planets—provide clues to their history, and the formation and evolution of the Solar System as a whole. Of additional interest is their potential to originate and host life.
Water worlds are of extreme interest to astrobiologists for their potential to develop life and sustain biological activity over geological timescales. The five best established water worlds in the Solar System include Europa, Enceladus, Ganymede, and Callisto. A host of other bodies in the outer Solar System are inferred by a single type of observation or by theoretical modeling to have subsurface oceans, and these include: Dione, Pluto, Triton, and Ceres, as well as Mimas, Eris, and Oberon. read more
Rho Ophiuchi Wide Field
Stars, Dust, and Gas near NGC 3572
Against a stunning backdrop of thousands of galaxies, this odd-looking galaxy with the long streamer of stars appears to be racing through space, like a runaway pinwheel firework.
This picture of the galaxy UGC 10214 was taken by the Advanced Camera for Surveys (ACS), which was installed aboard the NASA/ESA Hubble Space Telescope in March (2002) during Servicing Mission 3B. Dubbed the ‘Tadpole’, this spiral galaxy is unlike the textbook images of stately galaxies. Its distorted shape was caused by a small interloper, a very blue, compact, galaxy visible in the upper left corner of the more massive Tadpole. The Tadpole resides about 420 million light-years away in the constellation Draco.
Credit: NASA, Holland Ford (JHU), the ACS Science Team and ESA
The Spindle Galaxy (NGC 5866), a lenticular galaxy in the Draco constellation. This image shows that lenticular galaxies may retain a considerable amount of dust in their disk. There is little to no gas and thus they are considered deficient in interstellar matter.
NASA, ESA, and The Hubble Heritage Team (STScI/AURA
Clouds of the Large Magellanic Cloud
The Galaxy, the Jet, and the Black Hole