If life on Earth has taught us anything, it is that where you find liquid water, you generally find life. Looking at our solar system, we now have good reason to conclude that at least a handful of moons — Europa, Ganymede, Callisto, Enceladus, Titan, and possibly Triton — may harbor vast bodies of liquid water beneath their icy shells.

These are worlds where life could be living today, right now! We just need to get out there and explore.

To truly revolutionize our understanding of the science of biology and to understand how this bizarre little phenomenon called life works, we need to find life that we can poke and prod. We need to be able to investigate its fundamental biochemistry and see what makes it tick. Fossils don’t get us far when it comes to addressing these questions.

Europa is, in my opinion, the best place to search for existing life. I think it has the water, elements, and chemical energy needed to give rise to, and support, life as we know it. The 10-meter Keck II Telescope has shown that salty ocean water from below Europa’s ice may be reaching the surface, and thus its icy shell could be a window into the ocean below.

We also measured the presence of hydrogen peroxide across Europa’s surface, and we argue that if the peroxide gets mixed into the ocean, then it could help provide some of the chemistry needed to power life. Finding life on Europa almost certainly would be the discovery of a second, independent origin of life in our solar system.

Such a discovery would signal that the origin of life is relatively easy and that life arises wherever the conditions are right. We could then, with some confidence, look up at our night sky with the knowledge that we are looking out into a vast, biological universe.

Fast News: Astronomers detail new supernova category



Twenty-five stellar blasts form a separate class of supernova, say Ryan Foley of the Harvard-Smithsonian Center for Astrophysics and colleagues. These supernovae have emitted light similar to, but far less energetic than that from type la supernovae — the more common blasts that helped scientists determine that the universe’s expansion is speeding up.

A study describing this new class appeared in the April 10 (2013) issue of The Astrophysical Journal. Each of these explosions, identified as type lax, ejects material equal to about half the mass of our Sun and likely arises from a portion of a stellar remnant called a white dwarf.

The blast’s light out-put shows no sign of hydrogen and has the same shape over time as type la. Type lax ejecta also travel slower than type la. Scientists expect that the future Large Synoptic Survey Telescope — scheduled to be up and running by 2020— will find roughly 10,000 more members of this class and thus enable additional observations.