Earth Photobombs Saturn

Back in July, NASA’s Cassini spacecraft happened to be in perfect alignment with Saturn and the Sun (the technical term for that is syzygy, by the way!).  This allowed Cassini to take an amazing snapshot of a Saturnian eclipse.  If you haven’t seen this picture yet, you really need to check it out (click on the image below to see a larger, more detailed version).

IDL TIFF file
Click image to see full scale version, courtesy of Astronomy Picture of the Day.

Cassini has taken other pictures of Saturn eclipsing the Sun, but this one is particularly special.  Far off in the background, you can see a tiny, blue speck; namely, Earth.  If you look closely, you might be able to see the even tinier speck beside it: our beloved Moon.  Venus and Mars are also in the photo, meaning that in this one picture you can see half the planets in the Solar System all at once (or almost half, depending on your opinion about Pluto).

But wait, there’s more!  If you click on the image and view the full-scale version, you should be able to find at least three of Saturn’s moons.  Just below Saturn and slightly to the left, you should see a small, tan-colored moon which I’m guessing is Titan, and there’s another moon nearby that’s almost certainly Enceladus (the geysers give it away).  A third moon is located in the upper right, but most of it is in shadow so I can’t guess what its name might be.

We know for a fact that there is life—lots and lots of life—crammed onto that one tiny, blue speck, but we Earthlings might not be alone.  According to recent theories, there are four other places in the Solar System that might be able to support life: Mars, Europa (a moon of Jupiter), Titan, and Enceladus.  So it’s possible that this picture doesn’t just show a bunch of cool planets and moons.  It may also be our first group photo with the Martians, Titanians, and Enceladians.  This picture might be the first to show all the life bearing worlds of the Solar System together (or almost all of them—sorry, Europa—we’ll try to squeeze you in next time).

As you can tell, I’ve spent an embarrassingly large amount of time studying this image and thinking about what it means.  It’s stuff like this that keeps me from getting too bogged down with earthly concerns.  Pictures like this remind me that I’m a citizen of a much bigger, much wider universe.  So I want to send a big thank you to the Cassini spacecraft for sending back such an awesome photo!

P.S.: Click here for another cool picture of Earth and the Moon.  This one’s close enough that we’re not reduced to a tiny, nearly invisible speck, but still far enough away to show how truly small our planet is.  The picture was taken by the MESSINGER spacecraft while on route to Mercury.

Alien Mermaids

So far, we’ve discovered hundreds of exoplanets, planets outside our Solar System, and of those exoplanets we’ve found at least three that may be able to support life.  But our search for extraterrestrials doesn’t have to go as far as other star systems.  The odds of finding alien life right here in our Solar System are increasing.

Water is essential for life.  You and I are made of about 60% water, yet water in liquid form is extremely rare.  Even here on Earth, there isn’t as much as you might think, as illustrated by a recent image on Astronomy Picture of the Day (click here to see it).  Liquid water is almost nonexistent in other parts of the Solar System.

Yet scientists have found evidence of liquid water on the surface Mars, melting from the polar ice caps during the warmer seasons.  There’s evidence of subsurface oceans on Jupiter’s moon Europa and Saturn’s moon Enceladus.  Now the Cassini spacecraft has reportedly found another subsurface ocean on Titan, one of Saturn’s other moons (click here for more information).

I don’t know if Titan has life, but if we keep finding sources of liquid water we are bound to find life somewhere.  This life would probably be bacterial.  There could also be some kind of fish.  Or maybe one of these subsurface oceans supports a civilization of alien mermaids.

What? It’s possible.