I recently got an invite to use the beta release of Hulu, an online video streaming service that is now open to the public. It has some nice features; the video quality is excellent (let’s face it, YouTube videos are really awful), but it sticks commercials in the videos and they cannot be skipped or muted (except by muting your computer audio). I understand why they do this, but ick. It’s not much different than simply watching TV on your computer, except, of course, it’s an On Demand service.

So when I was fooling with it a couple of weeks go, I searched for anything related to astronomy, and got precisely one hit: an episode of the TV show The Nanny and The Professor, a sitcom from early 1970. I watched this show when I was a wee lad, but had completely forgotten about it. A professor hires a British nanny to watch his kids, and it turns out she has some subtle magic powers. You can always tell when she uses them because the soundtrack plays a little riff, and then there is canned laughter.

Anyway, there is an episode about astronomy, and I have to admit, for a lily-white 1970 TV show it was pretty good, though of course saccharine sweet.

I was impressed by the portrayal of the father (who is supportive), the way astronomy was used — almost entirely correctly, though there is some confusion over a solar and lunar eclipse, as well as what a comet looks like — and especially over the goofy astronomer who is actually seen as kindly and supportive as well. He has a great line when he encourages a boy to pursue astronomy: "You won’t become rich, but you’ll live with such beauty. "

Sounds familiar, right? Actually, he may look familiar too: the actor is Sam Jaffe, who played Professor Barnhardt in "The Day The Earth Stood Still". Or you might recognize him from "Battle Beyond the Stars". No? Well, that’s probably OK as well; I try to block my memory of that movie as well.

Anyway, if you have an extra half hour sometime, you might enjoy this episode. But keep some insulin handy.

Miss Frye over at Observations at Missy’s Window is hosting the latest Carnival of Space. I’ve had a somewhat busy week, and forgot to send her one of my own posts, but if you’re here it means you probably read ‘em all anyway. But head on over there and take a gander; as usual there’s lots of good stuff there, and you might find a new blog or two to stick into your feed reader.

And if you like it, show her the love on Digg.

Also, Cassini made it through the water plumes of Enceladus yesterday, and has returned lots of images. I’ll talk about those later.

Could there be another planet lurking in the dark, frigid outskirts of the solar system?

This isn’t as silly as it seems at first. No, I’m not talking Nibiru or any of that other nonsense (and it is nonsense), I’m talking about an actual planet, Earth-sized or so, that could be orbiting the Sun well beyond Pluto Neptune.

Why would we think there might be one out there?

We see some stars in the midst of forming planets. The stars are surrounded by thick disks of material, and in some we can actually see gaps in the disk, dark rings like the gaps in Saturn’s rings, that we think are due to forming planets gobbling up material in the ring. You’d think the disk would fade away with distance form the star, like our air gets thinner with altitude. But some disks appear to have sharp outer edges. This can be caused by a planet orbiting outside the disk; its gravity sweeps up the material and over time cleans up everything farther out. In one disk, this sharp boundary indicates a planet 200 AU out (an AU is the distance of the Earth to the Sun, about 150 million kilometers or 93 million miles).

Neptune orbits at 30 AU from the Sun, so 200 AU is a long way out. Could a planet like that have formed in our solar system? Maybe. Thing is, while our proto-planetary disk has been gone for billions of years, we do have lots of objects out past Neptune: the Trans-Neptunian Objects (they have lots of names, including Kuiper Belt Objects). These are basically giant balls of ice, some hundreds of miles across. As a group they form a puffy disk of objects stretching from Neptune’s orbit outward… but they seem to abruptly stop past about 50 AU out from the Sun. That’s called the Kuiper Cliff, the cause of which is unknown. Incidentally, it’s not because they’re too faint to see (that is, they’re there but we can’t spot them); at that distance we should have spotted lots of them by now.

Not only that, but a lot of these objects have orbits that are tilted more and are more elliptical than you’d expect if they just formed a long time ago and were left alone. Theyir orbits don’t bring them in very close — they tend to stay outside of Neptune’s orbit — but again, this is something that needs to be explained.

Could it be that there is another massive planet orbiting the Sun, way out there, which has swept up the objects gravitationally, creating the Kuiper Cliff and tossing the iceballs into tilted, oval orbits?

A newly released paper shows that may very well be the case. A team of scientists ran a whole mess of simulations, and found that a small planet (in this case, around half the size of the Earth) could have formed inside Neptune’s orbit (where there was plenty of material in the early solar system), gotten tossed into a bigger orbit by Neptune, and then knocked around the orbits of the iceballs, distorting their orbits and creating the Kuiper Cliff.

This idea is not new, but this new research is a provocative indicator of such a planet’s likelihood of existence. I’m not saying it’s out there, but it’s worth looking for. In fact, I’ve been saying that since about 1998 or so, when I worked on Hubble and was involved with a project that found a truncated disk around another star. I even worked with another astronomer on the team to investigate whether the robotic telescopes used to look for Near Earth Asteroids could spot such a planet.

It’s not all that easy. It wouldn’t be too faint to see, necessarily, but it’s a big sky. At that distance, the planet would move slowly, and the orbital motion would be hard to distinguish given the procedures used by NEA searches. We tried to convince some of them to modify their software to look for Planet X (yes, why not, though now it would be Planet IX), but we were met with mixed success. The fact that no one has discovered this planet shows you that this is still hard to do.

But maybe, just maybe, with this new research we’ll get people looking more seriously. It’s amazing to me that we can understand so much about galaxies and hugely distant objects, but find that there may be surprises waiting for us in our own back yard.