Penitentes on the Andes mountains on Earth. Is there something similar on Europa as well?
Credit: Wikimedia Commons
Europa is a fascinating little world, a moon with an icy crust and a subsurface global ocean. The environment is similar to the ice-covered waters at the Earth’s poles. Now scientists think that there may be another feature which is also found on Earth - huge frozen spikes of ice on the surface.
The five known moons of Pluto in an image taken by the Hubble Space Telescope.
Credit: NASA / ESA / M. Showalter (SETI Institute)
When Pluto was first discovered, it wasn’t known if it had any moons, and it was already a tiny world itself, smaller than Mercury (which doesn’t have any moons). As of last year however, five moons have been found orbiting Pluto! Now a new study announced today suggests that there may be up to ten more little moons or moonlets keeping Pluto company in the outer fringes of the solar system.
It is thought that one or more of the icy moons of the outer solar system could support life.
Credit: NASA Planetary Photojournal
(My first article for AmericaSpace, republished here.)
Until relatively recently, it was thought that the best, or perhaps only, place to look for life elsewhere in the solar system was Mars. The other inner planets were much too hot while the outer gas and ice giants were far too cold – the chances of any kind of life being found, even microbes, was considered extremely unlikely at best.
Image of Saturn’s tiny egg-shaped moon Methone taken by the Cassini spacecraft.
Credit: NASA / JPL-Caltech / Malin Space Science Institute
It might seem that way in this new photo released on November 5, 2012, taken by the orbiting Cassini spacecraft, but this is actually the tiny moon Methone. The oblong shape and smooth surface make Methone look more like a huge egg than a moon.
Earth and Moon. Credit: NASA
Ever since a study conducted back in 1993, it has been proposed that in order for a planet to support more complex life, it would be most advantageous for that planet to have a large moon orbiting it, much like the Earth’s moon. Our moon helps to stabilize the Earth’s rotational axis against perturbations caused by the gravitational influence of Jupiter. Without that stabilizing force, there would be huge climate fluctuations caused by the tilt of Earth’s axis swinging between about 0 and 85 degrees…
See Universe Today for the full article.
Until fairly recently, the search for life elsewhere in the solar system has focused primarily on Mars, as it is the most Earth-like of all the other planets in the solar system. The possibility of finding any kind of life farther out in the outer solar system was considered very unlikely at best; too cold, too little sunlight, no solid surfaces on the gas giants and no atmospheres to speak of on any of the moons apart from Titan…
See Universe Today for the full article.
(Note: this and future articles written for Universe Today are exclusive, therefore only a summary is posted here, which will link to the full article on UT).
Pluto may have been demoted from full planetary status (now classified as a dwarf planet), but the tiny icy world has now been found to have a fourth moon, discovered by the Hubble Space Telescope on June 28, 2011 and temporarily named P4. Even Mercury is larger than Pluto, yet has no known moon, and neither does Venus, which is almost the same size as Earth. But little Pluto has at least four that we know of! The image below shows all four moons around Pluto (Charon, Hydra, Nix and P4):
Credit: NASA, ESA, and M. Showalter (SETI Institute)
Even with Hubble, the moons are not much more than pinpoints of light, but hopefully the New Horizons spacecraft will get a closer look when it arrives at Pluto in 2015…