Having A Look At Io And Pluto

I know I've written about some serious Earth-based stuff lately, and it might be a bit jarring to jump back out into space, but this is just so cool and interesting. I had to let you see it too. Dr. Tony Phillips, has the latest from NASA's ventures in space exploration, complete with pictures. For those of you who don't know, NASA has a spacecraft headed out to Pluto. The craft is named New Horizons, and it's carrying an eight-inch telescope called LORRI, short for Long Range Reconnaissance Imager. They're looking to snap some high resolution pics of the recently-demoted dwarf planet and its moons, sometime around 2015. To get her there on schedule, NASA decided that New Horizons needed a speed boost on the way out to the fringes of our solar system, so they swung her by Jupiter, to slingshot around the giant planet and pick up 9,000 mph of extra giddy-up. This will cut five years off the trip--well worth the detour, wouldn't you say?

Now, since New Horizons was doing a flyby of the big guy anyway, of course NASA seized the opportunity to take a few photos of Jupiter and the multiple moons hanging out in the vicinity. In fact, LORRI didn't waste any time, snapping a whole gallery of images of Io, Europa, Callisto and Ganymede. They're all interesting in their own ways, but it's Io that captured the attention of NASA's old hands. LORRI caught Io's Tvashtar volcano in fine form; the erupting plume image is the best "longtime Jupiter experts -- have ever seen." No kidding--the plume rises 180 miles above the surface of the moon! (I almost said "into the air," but that doesn't quite work on Io, now does it?) If you follow the link to the article, the photo is there for your viewing pleasure, along with a link to other pics that LORRI shot in the neighborhood.

One of the rather amazing things about this eruption on Io is what the photo shows happens when the plume gets that high in that environment. Dr. Phillips quotes Andy Cheng, a scientist from Johns Hopkins' Applied Physics Lab:

"The patchy and filamentous structure seen in the Tvashtar plume suggests to me that condensation from gas to solid particulates is occurring," he says. In other words, the gas could be crystallizing in the cold space above Io to form a kind of sulfurous snow.

Volcanoes spewing snow? It is an alien world.

Alien, indeed. In case I haven't mentioned it before (of course I have)--I want to go there!! Things are happening out there, and I'm missing them--or, at least I would be, if it weren't for New Horizons. Fortunately, LORRI was there at the right place at the right time; although, the chances were pretty good that LORRI would catch something interesting no matter when she showed up. Apparently, this kind of action isn't rare on this particular Jupitorial satellite. Io, is a rather volcanically active little guy. According to Dr. Phillips:

Gravitational forces exerted on Io by Jupiter and the other large moons raise tidal bulges in Io's solid crust 30 meters high. This flexing action, like the flexing of a paperclip, makes Io's interior molten hot and, as a result, the moon has hundreds of active volcanoes.

There's a nifty little animated graphic with Dr. Phillips' article which demonstrates all that tidal bulging. It looks a lot like a tennis ball flexing, when a video camera catches it in slow motion after it's been hit with a good strong forehand.

As New Horizons heads out to the farther reaches of our little corner of the galaxy, there are ever more discoveries to be made. Pluto awaits, and NASA plans to closely examine our little dwarf friend, and his immediate family:

"Future LORRI images of Pluto and Charon will have even more detail and higher resolution, because New Horizons will bring us at least a thousand times closer than we came to Io," notes Cheng. Of course, no one has any idea what LORRI will see, because Pluto has never been visited by a space probe. "That's why we're going."

One more interesting thing about Pluto and Charon: Wikipedia says that Pluto may get reclassified again, and Charon may come in for a bigger piece of the spotlight:

Pluto and its largest satellite, Charon, could be considered a binary system because they are closer in size than any of the other known celestial pair combinations in the solar system, and because the barycenter of their orbits does not lie within either body. However, the International Astronomical Union (IAU) has yet to formalize a definition for binary dwarf planets, so Charon is currently regarded as a moon of Pluto.

It might be hard for Pluto to face yet another change in status, but then again, maybe not. Pluto and Charon are close, you know, and Pluto may be happy to see his buddy get a little more attention. Besides, being a binary system would make Pluto kind of unique, in our neck of the woods anyway, and it might compensate for getting kicked out of the big boys' club. I'm not saying that Pluto has an ego. He may be perfectly humble, but if I was recently told I couldn't hang with the cool kids anymore, it would probably make me feel better if someone made a fuss over me for awhile, especially if I got to start a new club with my best friend.

Look, The Moon Is Full

I got the latest space-related tidbits from SpaceWeather.com this morning. It seems the Pluto lovers of the world are still up in arms that their favorite planet has been demoted to "dwarf" status. Some people just refuse to accept the new level of planet snobbery in the solar system, and the debate rages on. If you are among those still reeling from the notion that our neighborhood only has eight planets, Space Weather has a petition, with a place for comments, where you can add your two cents. Three even, if you're so inclined.

Another astronomical item of note is our very own satellite. Tonight's a full Moon, and it will be bigger and brighter than any other full Moon of 2006. Here's what Space Weather had to say about the why and wherefore:

What makes it big? Answer: The Moon's lopsided orbit. One side of the Moon's orbit is 50,000 km closer to Earth than the other side. The two sides are called, respectively, perigee, from Greek, meaning "close to Earth," and apogee, meaning "far from Earth." Tonight's Moon is at perigee.

In further action, eastern Europe, Asia, Africa and Australia will get the chance to see a partial lunar eclipse this evening, and there's some exciting sunspot activity for people who have the right telescope and filters to stare at our ball of fire in the sky. There's a nifty little animation of the lunar show if you follow the link at Space Weather. There's also a chart with recent near miss asteroid information, if you like to think of impending doom scenarios.

Well, I think that catches us up on Space Weather info. I'm out to work on our giant mountain of dirt in the back yard. I'll be in again when I need a rest, and I'll see what's going on in the world. I'll let you know if I find anything interesting.

Pluto Demoted

Poor Pluto can't get no respect. Remember that conference they were going to have where all the astronomy bigwigs were planning to decide what makes a planet a planet? The International Astronomical Union (IAU) General Assembly were scheduled to gather this week and cast their ballots for which astronomical bodies in our sun's orbit get invited to be on the official solar system "Who's Who" list. Well, today the vote happened, and Pluto is not going to get an invite. According to Spaceweather.com, Pluto, along with two others, Ceres and 2003 UB313 (I think that might be the one they call Xena) are being classified as "dwarf planets."

Now, from what I read before, a dwarf planet Pluto might have still been classed as a planet, except for the fact it doesn't meet one of the three planetary requirements that the IAU determined would be the standard by which planethood is to be judged. The three criteria are as follows (from Spaceweather.com):

(1) It must have enough mass and gravity to gather itself into a ball.

(2) It must orbit the sun.

(3) It must reign supreme in its own orbit, having "cleared the neighborhood" of other competing bodies.

So, Pluto fails to achieve full planet stature because he isn't a bully. He hasn't kicked out all the other kids in the neighborhood (or made them his satellite toadies.) There are loads of other large objects floating around out there in the Kuiper Belt where Pluto hangs out, thousands in fact. You could say that Pluto lives out in the suburbs with lots of other middle class objects, none of them important enough to live on their own private estates like Jupiter, Saturn and the other solar system hotshots with private gates and chauffeurs (and very high property taxes.)

I don't think this is as big a demotion as it sounds. Sure there are now officially only eight planets in our solar system, but there is also a new category just for Pluto, Ceres and 2003 UB313. Dwarf planets may not sound very important, but they're important enough to call a whole conference over, and have a vote and everything, and create a special category just for them; so Pluto's got to feel good about that. He's important enough to cause a fuss, and what more could any of us want, really? Actually, he may be better off this way. By Kuiper Belt standards, Pluto's still a big fish in a small pond, which might be preferable to being given full planet status and then having to try to keep up with the big boys. No, I think Pluto and the other dwarf planets can be very satisfied with today's decision. They get to feel superior to the mere asteroids in the neighborhood, without having to face a lot of planetary peer pressure--and their taxes will probably stay low, so who could complain about that?

What Makes A Planet A Planet?

What makes a planet a planet? It's been a big topic of debate in certain brainiac circles, and astronomers are set to put it to a vote next week in Prague. NPR's got the scoop, and David Kestenbaum writes (and thanks to him for teaching me almost all I know about Pluto) that the astronomy types are prepping a definition of planethood, so that we can all know, once and for all (until the next big debate), whether the solar system we all grew up with is going to be the one we take further into the new millennium. You know the solar system I mean: the sun in the middle and nine planets circling it for all they're worth. Actually the list of planets in our solar system is pretty likely to change, either getting smaller or larger, but not staying static. Since the last time we checked in with the order of things, somewhere around high school physics, there have been some new discoveries that call the familiar model into question, specifically at least one planet-like object, out past baby Pluto, that's bigger than Pluto is. It's called Xena, and has forced the astronomy debaters to debate this particular debatable issue. You see, they have to decide whether Xena's a planet, and that depends partly on whether Pluto's a planet.

So, what questions are the science gods considering? Taking it as a given that planets orbit suns (thanks to alert reader Su for pointing that out in the comments)--What defines a planet? Is it how big it is? Is it having a moon or two? Is it having enough gravity to make it round? (That is one of the criteria being debated. See, I knew major astronomical bodies were supposed to be round.) Is it having a relatively round orbital path in its journey around the big old ball of fire in the daytime sky? The answers to these questions will define whether our solar system models get bigger, or smaller in the coming years. You see, Pluto gets different status depending on which questions take precedence. While having a couple of moons of its own, Pluto is also tiny, smaller than the Earth's Moon. It's round, but has an orbit that's rather catawampous. If the debate tilts the wrong way for Pluto, the number of planets pops down to eight, but if it goes the other way, there might be a whole new category that bumps the count upward, since there are other items out in the Kuiper Belt (the gathering of hundreds of objects out at the fringe of our solar system of which Pluto is a part) that could qualify for planet status along with the undersized and familiar one we all know and love.

One of the proposals is to define a new class of planets. A panel of astronomy experts met in June to hammer out some possible definitions:

Several panel members have favored dividing planets into categories: terrestrial planets (Mercury, Venus, Earth, Mars), giant planets (Jupiter, Saturn, Uranus, Neptune) and a third class that would include Pluto.

"We'll call them dwarf planets or something," says Iwan Williams, an astronomer at the University of London who favors the idea and also served on the panel.

Sources say the panel's new definition for planets would, in fact, create a third category embracing Pluto.

The new category would also embrace Xena, since if Pluto qualifies, so does the Warrior Princess. A few others could take their place on the list, too, and then we would all get to argue about our favorite ancient Greek and Roman names to call them. Time to start watching Hercules reruns. Of course, first we have to decide whether they get their own category in the first place, and what to call that. Dwarf planets sound cute, don't you think? Let's vote for that! Oh yeah, only real astronomy buffs, with degrees and everything actually get to vote in Prague, and even with the voters kept to that reasonable minimum they aren't sure what the outcome will be:

It's unclear what astronomers will make of the new definition or how they will vote on it. Observers say the definition will have to be concise and unambiguous. What is too small to be a dwarf planet? Do moons count? What about round comets?

Oh goody, more questions. I love questions. I really do. All the best answers come from people asking questions. Since there aren't really answers yet, because nobody's actually voted yet, I have to leave you hanging on this one, but I'm sure I'll keep an eye out and pass the information along when it comes my way. Until then, try to think up those Greek-sounding names, okay? How about Podiatry, or Hermeneutics? Too esoteric? Oh well, see if you can do better.

Hat tip: Futurismic