Titan Is Escaping Saturn's Grip Far Faster Than We Thought

As a result of the complex gravitational forces at work between a planet and its moon(s), all moons slowly drift away from their host planet. Our own moon is moving away at a rate of 1.5 inches a year. Titan however is a bit of a speed demon. I'm not sure what transpired between it and Saturn in the past, but Titan is in an awful hurry to get away. Every year, it gets 4.3 inches further away. Yeah, that's not very much, but honestly, what were you expecting? That 4.3 inches is actually 100 times what scientists were predicting, so in that regard, we're talking blazing speed here.

Farewell to Cassini

Today, after 13 years orbiting Saturn, Cassini will burn up in the planet's atmosphere. This is being done to prevent Cassini from crashing into one of Saturn's moons, most notably Titan or Enceladus, to prevent any alien organisms from being exposed to any foreign objects from Earth, living or otherwise.

Credit: NASA/JPL

It's no secret that Cassini has had an incredibly rich and successful mission. It's done more than even the people behind it would have thought possible when they started. And with its demise, there's not a whole lot of representation in the outer solar system. There's Juno orbiting Jupiter, New Horizons somewhere out beyond Pluto, and that's it. And there are no immediate plans to send anything beyond Jupiter either. But there is certainly plenty of reason to go back to Saturn. Cassini has discovered so much. And so, to memorialize Cassini, let's take a look back at just what Cassini has added to the halls of science.

Discovered 7 new moons: Methone, Pallene, Polydeuces, Daphnis, Anthe, Aegaeon, S/2009 S 1 (Hey, it takes a while to name these things)

Landed the Huygens probe on the surface of Titan. This remains the only time we have landed anything in the outer solar system.

The confirmation of methane lakes on the surface of Titan. We were pretty sure they were there, it made sense, but now, thanks to Cassini, we know for sure. They're not quite big wide oceans like what we have on Earth, and Titan's lakes are confined to the polar regions, but they're there, and the biggest, Kraken Mare, is even bigger than the Caspian Sea on Earth.

The discovery of a subsurface ocean on Enceladus. Of all the things Cassini has done, and it's a lot, I haven't mentioned quite a bit, this is the biggest. I don't think anyone saw this coming. When the Voyagers passed by, they saw an icy little moon, surprisingly smooth and very bright (Enceladus is the most reflective body in the Solar System), but otherwise it was assumed that this was just another dead ball of ice, like most of Saturn's moons. Understandably, it was Titan that captured the imagination.

But when Cassini arrived, things began to change. First, Cassini found the "tiger stripes", a series of fractures in the southern polar region that could be less than a thousand years old. The entire region seemed to be less than a million years old. Then, geysers were discovered erupting from the same place. These geysers are actually the source of material for Saturn's E Ring. This is a dead giveaway, there was definitely a liquid water ocean underneath the surface, and while it was initially believed to be limited to the southern polar region, it's now accepted that the ocean covers the entire moon, and is likely a couple dozen kilometers deep. It's a miniature Europa, and without Cassini, we never would have known about it. It might even be easier to explore Enceladus than Europa, despite being twice as far away, because unlike Europa, Enceladus isn't bathed in lethal amounts of radiation.

Like I said, Cassini has done far more than what I've mentioned, but I think those are the big highlights. It's hard to argue with the accomplishments of Voyager, Hubble, or Spirit and Opportunity, but Cassini certainly isn't far behind in the annals of NASA's most successful missions. It's lived a good life, and a spectacular death dive into Saturn's atmosphere is a pretty good way to go out.

Cassini Has Been Good for Astrobiologists

As you may (or may not) be aware, Cassini's mission around Saturn will be coming to an end this year. For 13 years, Cassini has orbited Saturn, and has discovered a lot. I think that I'll make a more comprehensive post about Cassini closer to October, when Cassini performs its death dive into Saturn, but for now, I want to highlight this. It is interesting how a planet a billion miles away from the sun possesses two moons with the potential of hosting life. Enceladus especially has been a huge surprise. I don't think anyone was expecting Enceladus to be anything more than a ball of ice. But here we are today, with photo evidence of massive geysers spewing organic material out into space. Cassini doesn't have the capability to detect life, but the ingredients are there.

Then, of course, there's Titan. Titan is a fascinating place. A thick atmosphere, a methane cycle that mirrors Earth's water cycle, large methane seas hundreds of feet deep, even rivers of methane, Titan really does resemble an Earth in deep freeze. No one knows if life can use methane instead of water, there are pros and there are cons. But it would be very interesting to find out. Life on Enceladus would be, well, different to life on Earth, but not that different. It would be recognizable to us, and would probably resemble deep-sea life on Earth. But life on Titan? It would be a truly alien biochemistry.

Basically, we need to go back to Saturn. And soon. Enceladus and Titan are just too inviting as targets to resist. Mars is closer, and Europa is basically just a bigger Enceladus, but for my money, if there's life in the solar system, it'll be around Saturn.

All Space Flight is Important

This past week has not been a good one for space exploration's public image. Two rockets down, with one man dead. Frankly, considering the vehicle, I can't believe the second man on that ship lived. I'm sure it's caused a lot of people to question the validity and the entire point of space travel. To the regular person, it doesn't seem worth it. I know I've talked about this plenty before, and I'm sure I'll talk about it again. SpaceShipTwo was a space tourism vessel, and in terms of importance, well, there are more important things. However, I don't want people associating that with all space flight.

This is an article about how in a few years, NASA will be bringing most of its planetary space probe missions to an end. After that, we'll be left with very little in the way of new and exciting information about the planets. I've noticed a picture of Titan's lakes circulating through the internet today, in a few years, spectacular images like this will be no more. Manned space flight is important, but so is unmanned. Space probes go where we cannot, they can go further, longer, and they can do it for far less money. Landing a man on Mars may get all the press, but sending a probe to sail on Ligeia Mare, or to drill through Europa's icy crust to the ocean beneath would be just as epic a milestone, and would probably return even more spectacular results.

In an unrelated bit of news, I've got a couple of longer, more involved posts in the works, and hopefully I can get them out this week. They'll be different from my normal fare, so...yes. That will be happening, I guess.

My Twitter