Correct. Then Hubble started to take imagry of Pluto showing that it had more of an atmosphere than it should have. The problem with that is that there is no, at least no known, way to pump energy into Pluto like there is with Europa, Enceladus, Titan, even the earth. So, where does the "air" come from? the thing that has me shocked is that I was expecting a body like Ceres with a bit of Triton mixed in. But as we know, the joy of looking at something completely new is that you get a whole series of questions that you did not know about prior. Why are there big dark spots on the side of Pluto facing Charon? What is that giant flat, smooth area that looks like a Heart? WHY ARE THERE NO CRATERS? I mean, wow, NO CRATERS! not even any big ones! If there was a giant impactor that split the proto-Pluto into the current Pluto system, should there not be some scars from that? Why is the atmosphere of Pluto bigger than expected? Pluto has ice caps! ICE CAPS! What is that giant dark spot on Charon's pole area? It is going to take 20 months to get all this data back to earth, then it is going to take a year minimum to figure out what the heck we are looking at. So at least a half-decade of questions and hopefully answers about this place. My big BIG hope is that Pluto is so weird that it fuels the desire for the Neptune Orbiter; Triton is about the same size as Pluto and we think it is a captured Plutino object. I doubt we will go back to Pluto anytime in my lifetime and an orbiter will take 20 years to get there anyway so what we have now is all we are going to get. But Neptune is doable in the near future. TLDR: Space is awesome.
Sure. Europa has a liquid ocean of water under its ice. But Europa is small and should be frozen solid. So you need a source of energy to melt that water ice. It turns out that the tug of gravity from Jupiter, Io and Ganymede create tides in Europa that pull and tug on it; this generates energy as the internals flex and rub up against itself. In the earth, the moon, creates tides that we see at the ocean, but it also creates tides in the earth itself, some 2-3 feet at the equator. Enceladus has a pool of liquid that is heated from the push and pull of the gravitational tug of war between Saturn and Titan. Pluto, however, has no source of tidal energy input. Pluto and Charon are in a gravitational equilibrium; there is no tug of gravity inputting energy into either body, or at least there does not appear to be. Because Pluto and Charon are tidally locked to each other both in revolution and rotation, there is no push-pull like in the other small bodies listed above. So, why is there so much gas above the surface of Pluto? Where did it come from? Why is the surface of Pluto so young and crater free? And yea, this excites me. I've seen Pluto with my own eyes through a 25" telescope as nothing more than a very faint dot that barely moved over two nights. Now, that dot is a whole world with strange geology. I'm going to do an outreach event tonight showing 200-300 people Saturn, and I expect a lot of Pluto questions as well.
Ahhh! I did not know this. That does make it interesting. Thank you. I had a 10" Dobsonian back in the day; I looked into the logistics of looking at Pluto and decided that it was well beyond my means. I think the biggest glass I've ever looked through was a 20". So this begs the question - what do you do and where do you do it? because about the only regret I have in moving from New Mexico to Washington was the lack of easy deep sky...Because Pluto and Charon are tidally locked to each other both in revolution and rotation, there is no push-pull like in the other small bodies listed above.
I've seen Pluto with my own eyes through a 25" telescope as nothing more than a very faint dot that barely moved over two nights.
I moved from the California desert to the Ohio Valley. Every time there is something to look at in the sky I debate moving back west, then the bills come due and I am glad that I am here. There is something to be said for a $350 mortgage payment that all the clear dark sky in the world can't overcome. Our Astronomy Society does a lot of outreach trying to keep membership up enough to fund the fun stuff we like to do. We own 40 acres out about an hour away from town that is dark enough to see M13, M3 and M31 with the naked eye on good nights. The bad news is that the last year or so has been the worst weather wise in 12 years I have been out here. We are right under the jet stream, its hot as ass and twice as humid. When it gets a bit cooler and starts getting dark at 8PM again I do stuff with the library as well. As for where, I have an agreement with the city and two different grocery stores that I can set up my scope and let people look. Tonight I am going to set up in a city park and hope for clear enough skies to get a few hundred people a chance to look at Saturn. The moon is too close to the sun to let randoms look through the scope, but next week will be first quarter and that will be a big draw during the day and we can hit 1000 people a day looking through a scope. Out of those 1000, 100 will take a flier, 20 will contact the facebook group and 1 or two will send messages about either "hey come to our school!" or will actually join the club. But I get to talk about space and nerd out for a few hours, so that makes me happy. Pluto is considered a "challenging" object for anything under a 12" scope. If you have a camera and a good mount, a 4" scope can get an image, assuming you know what you are doing. There is a group of people who have been able to visually observe Charon! They were in the mountains, over 9000 feet above sea level and using 36" dobsonians, but they were able to watch Charon revolve around Pluto over a week. This is one of those things where knowing that the object exists helps you more than you care to admit. I'm going to a star party in West Virginia next month in the shadow of the NRAO and get to go on a full site tour. but damn if I don't miss star gazing at 8500 feet in the Sierras. That was an experience that everyone needs to do at least once.
Although they are tidally locked, that estimate is at first order. How much energy do higher order instabilities contribute to energy generation? Is it something sufficient to keep in motion something that has been previously set?
That is an interesting question I did not think of before. I guess that depends on how long ago Pluto and Charon became tidally locked. When I see Dr. Harold Geller next month I'll ask that question. Maybe we will have more data and can at least start to guess.
I cant wait to hear more results from the data!
Also, could you elaborate on why you think that ice caps are so surprising? Pluto has an atmosphere that is in equilibrium with the ices on the surface, so it would redeposit these ices on the surface. More ice would be deposited towards the poles since they are the coldest areas. Also, more ice will sublimate in the warmer areas near the equator. Pluto is very far from the sun, so these differences shouldn't be too pronounced, but as you can see they are not.. It is possible however that there is something else that I'm not considering that would make Pluto unlikely to have ice caps.
Damn it Hubski, I have to go outside! Why are the polar caps surprising? Pluto is like Uranus in that the poles are in its orbital plane. I honestly did not expect polar caps for that reason. If anything, the pole that is lit up by the sun, I anticipated to have less ices on it, and a stronger methane and carbon monoxide signature in the shadowed part of the body. We already expected there to be methane and CO ices on the surface, but in an actual polar cap in the part of the globe in constant sunlight was something neat to see.
Why would you want to go outside, when inside is where all of the cool space stuff is? Pluto does rotate on its side, but its pole isn't (currently) always facing the sun. In fact, the sun is currently mostly heating the equator. Here is its current orientation, and more details.
Very nice! I live in Orlando and am involved with an Astronomy Society here. We have a few 8" telescopes and one 21" (in the Robinson Observatory). I know your pain of trying to cut through light pollution (damn Disney) and humidity and poor conditions. Have fun with all of that!
We sat outside as long as we could stand it. not nearly the crowd we usually pull in but 200+ anyway. I try to hit the public the week around first quarter as I can have the scopes up and looking at the moon for a few hours before sunset and hype Saturn at nightfall (9:30PM up here). We dodged clouds all evening but managed to get Saturn at 200x for most of the evening. That is good enough to see 4-5 moons and the Cassini division. And there was a ton of Pluto talk. Next outreach I have to bring my globes to explain how big Pluto, the moon and the earth are.
No. Not necessarily. Pluto has a very active geology. It is very possible that this event happened long enough in the past that all evidence has been wiped away, or covered by the deposition of ices from its atmosphere. EDIT: This active geology is also why we see so few craters.If there was a giant impactor that split the proto-Pluto into the current Pluto system, should there not be some scars from that?
Was anyone expecting an active geology? I read that some people were expecting a dead, more cratered Triton, but the lack of craters seems to have taken everyone by surprise. And yes atmosphere is being mentioned, and that can be a factor, but we are talking thinner than the Martian atmosphere here. Pluto is tiny, roughly 1/2 the diameter of the moon, and this preliminary data is showing it acting more like a comet than a planet. Can an atmosphere that thin erase that much geology? Or does Pluto get close enough to the sun every 200 years to melt the surface enough to reform the surface?Pluto has a very active geology. It is very possible that this event happened long enough in the past that all evidence has been wiped away, or covered by the deposition of ices from its atmosphere.
There was a little bit of speculation because of the atmosphere that was detected by the Hubble, but largely, no. That idea was mostly ignored because we weren't sure what could CAUSE an active geology on an object as small as Pluto. Yes, Pluto's atmosphere is incredibly thin, but something to remember is that while on something like Mars, the only means of the atmosphere destroying evidence of craters is erosive factors like wind, on Pluto the atmosphere is also in equilibrium with the ices on the surface. Ice will "frost" out of the atmosphere and blanket the surface, covering up a lot of features. The ice is melting more on the parts that face the sun and depositing more on the parts that are not. This difference isn't a lot, but it's enough to add up over time. Pluto is also, as you mentioned in your previous post, orbiting "on its side", which means that this deposited ice is melted off of the summer side and redeposited on the winter side over and over for each orbital period. This type of cycling could easily cover up evidence of craters. This was expected. Compositionally, Pluto IS a comet, just a very large one. The tail was expected when we saw that the atmosphere was so large. We expected its atmosphere to be in the process of being depleted. The tail always points away from the sun, so we couldn't have detected it until we got behind it, this is just confirmation.Was anyone expecting an active geology?
And yes atmosphere is being mentioned, and that can be a factor, but we are talking thinner than the Martian atmosphere here.
this preliminary data is showing it acting more like a comet than a planet.
why 20 years? is it because you are imagining a complete redesign of the mission? Perhaps a little rover? How I wish we had one in every large object in the solar system.
Way back in 2003 there was a plan for a Pluto orbiter and "hopper" lander. The trip out to Pluto was going to be 14-16 years depending on the launch window. So, 2-3 years to build the thing, then launch, then get there, then deal with the data transfer back home assuming all goes well. This is where I got the 20 years from. And if we are going to go back to Pluto, IMO, we should go to orbit and land, stay a while, and push our abilities to the limit. Link to the idea for the mission is here but they could not get the funding, and got New Horizons pushed through instead.why 20 years?
For those curious, this hypothetical mission would take longer to get to Pluto than New Horizons because it wouldn't just be flying by, it would need time to set up a slower approach and enter into orbit around Pluto and give the lander time to collect the sample. It would also need enough fuel to then change trajectories and return to Earth, as well as all of the fuel for the lander. These types of sample return missions are very expensive, which is why there have not been many. There were a few somewhat famous ones to the moon in the 60s and 70s, one that collected solar wind particles (barely had to leave the Earth's neighborhood, no landing required), one that flew through the tail of a comet and collected dust (no landing required), and one by JAXA that retrieved a sample from an asteroid. It's ultimately cheaper to bring the science/instrumentation to the object than the other way around, and those are the types of missions that get funding. A rover is far more likely than a sample return mission, but even so I wouldn't put money on a return to Pluto in the very near future.
And we don't have the plutonium for the power anymore due to nuclear arms limitations. And investing a 30 year career into one mission is much to ask of a scientist. And if you don't make the mission an international treaty with concrete spending and mission statements, the congress 10 years out will cut your mission funding. And and and... sigh, It can be done if we have the will. But that is the case in most things, is it not? Also that Hauyabusa mission is a study is disaster engineering. Everything that could go wrong at some point did, yet they still were able to hit the earth's atmosphere and land in Australia, albeit a bit later than planned. This is the mission that the idea of "Never give up! Never Surrender!" was a real battle cry. And now they are trying to rescue the Venus orbiter with seat of the pants engineering as well. I feel bad that JAXA has had a string of bad luck, but watching them recover has been amazing.
Well, you need someone like Alan Stern. He invested his whole career into New Horizons and he is pretty much the only reason why it happened and became the success that it is and has been so far. You know, his son Jordan is about to start grad school... Unfortunately I don't think that he's up for following in his father's footsteps. He's a math major in undergrad rather than anything astronomy related. Understandable that he wanted the chance to prove himself on his own rather than live in his father's shadow. But my point is that we need someone with that kind of drive and determination to get a mission through. The type of person where no matter what happens they keep trying until they finish the job. Maybe whoever was in charge of the Hayabusa?