NASA/JPL-Caltech
The small icy and rocky bodies of the Solar System are clearly eager for the spotlight this year. The latest exciting news comes from the Cassini Spacecraft in orbit around Saturn. Previously Cassini had detected water geysers on the south pole of Saturn’s moon, Enceladus. Now new data indicated that the moon could have a subsurface ocean about 10 km deep and as big as Lake Superior. The evidence comes from measurements of the gravitation field of the moon, i.e., how the moon affects the path of the Cassini spacecraft as it flies by. Small changes in the detected pull of gravity from Enceladus are caused by variations in its internal structure (how the density of the moon varies from its surface to its core). For comparison, Earth has a solid iron core, a liquid iron core, a somewhat liquid-like mantle of melted rock, and a solid crust. Enceladus, we now think, has a rocky silicate core, an icy mantle and crust, and a liquid salt water ocean at least under its south pole. Planetary scientists are over the moon (pun intended) about this news as it expands our horizon of places to look for signs of life within our own Solar System and in other extrasolar systems. We used to think the only place to look was in the habitable zone of the Sun, or the host star, but Europa and Enceladus have now forced us to think differently.
And now for more geek to help you think differently, or at least think:
Have a great week!@Summer_Ash
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