Deep Space and Interplanetary Exploration - The Universe is Timeless

[Wrangler]

Glad there time to recover the ship, it be terrible loss of work if the ship passed without a being able carry it's mission.  Man this may get nail biting if more of this happens.

I was more worried they'd run into debris when cruise between Pluto and moons.

[BirdofPrey]

They announced a few weeks ago that they had determined that the path was clear of debris.

In other news.  It still bugs me that Pluto has bee deemed a dwarf planet.
. . .
It should be a double dwarf planet since the barycenter is outside Pluto between it and Charon

[Sabelkatten]

Technically, Pluto would still be a dwarf planet - just part of a multi-planet system. :)

Personally I rather like the changed definitions. It provides a good classification for all those small "would-have-been-a-moon-if-there-just-had-been-something-big-enough-around" worldlets that are really too big to be called simply "asteroids" (Ceres, I'm looking at you! :D ).

[ANS Kamas P81]

So it seems Philae has found something.  Potentially, to quote 2010..."Something wonderful."

[url]http://news.sky.com/story/1514080/alien-life-on-philae-comet-scientists-sayp/url]

Granted, I'd say any such claims are highly dubious and require EXTREME levels of proof, but they bring up some interesting points.

It has a black hydrocarbon crust overlaying ice, smooth icy "seas", and flat-bottomed craters containing "lakes" of re-frozen water overlain with organic debris.

Prof Wickramasinghe said: "What we're saying is that data coming from the comet seems to unequivocally, in my opinion, point to micro-organisms being involved in the formation of the icy structures, the preponderance of aromatic hydrocarbons, and the very dark surface.

"These are not easily explained in terms of pre-biotic chemistry.

"The dark material is being constantly replenished as it is boiled off by heat from the Sun. Something must be doing that at a fairly prolific rate."(emphasis mine)

Whatever it is, it might just be growing.  Now there's a host of possibilities for that.  The biggest thing will be disproving that there's any sign of earth life; We have plenty of micrometeors and debris from MARS on this planet; it would clearly suggest that over time similar portions of Earth have been spread into and contaminating the rest of the Solar System to some small degree. And like an old milk jug with a little bit left inside growing fungus, perhaps a touch of said extremophile life from earth found it and thought it tasted pretty damn good.

That is, assuming it's not something like a non-organic, thin liquid pocket saturated with carbon dust being the black thing that is being replenished, caused by the probe cracking the surface of the comet and opening up a hole.  However, there's also the detection of organic carbon-based molecules around the comet itself, so...

...I think it might be time to send a new probe, if there's any way to get a closer look at the Black Stuff.

[kato]

Personally I rather like the changed definitions. It provides a good classification for all those small "would-have-been-a-moon-if-there-just-had-been-something-big-enough-around" worldlets that are really too big to be called simply "asteroids" (Ceres, I'm looking at you! :D ).

Meh, the criteria are wonky though. They should just decide by sheer size.


If one instead groups based solely on relative size to the smallest known object in hydrostatic equilibrium (which of course is an arbitrary sort key too), the list of objects in the solar system would look like this:

Code: [Select]

Rocks
a) Radius under 32 km (under 0.16 times Mimas' size) - billions of objects plus 131 known moons.

Asteroids
Note: Notable rocks.
a) Radius 32 - 66 km (0.16-0.33 times Mimas' size) - about 400 known objects plus 15 known moons.
b) Radius 66 - 200 km (0.33-1.00 times Mimas' size) - about 110 known objects plus 14 known moons.

Planetoids and equivalent-sized moons
Note: All dwarf planets go here.
a) Radius 200 - 600 km (1-3 times Mimas' size) - 43 known objects plus 8 moons.
b) Radius 600 - 1,200 km (3-6 times Mimas' size) - 3 known objects plus 5 moons.
c) Radius 1,200 - 2,000 km (6-10 times Mimas' size) - 4 moons.

Terrestrials and equivalent-sized moons
Note: Grouping rocks larger than dwarf planets.
a) Radius 2,000 - 3,000 km (10-15 times Mimas' size) - 1 object (Mercury) plus 3 moons (Ganymede, Callisto, Titan)
b) Radius 3,000 - 4,200 km (15-21 times Mimas' size) - 1 object (Mars)
c) Radius 4,200 - 5,600 km (21-28 times Mimas' size) - nothing
d) Radius 5,600 - 7,200 km (28-36 times Mimas' size) - 2 objects (Venus and Earth)

Gas Dwarfs and Super-Earths
Note: Not existant in Solar System, but otherwise.
a) Radius 7,200 - 9,000 km (36-45 times Mimas' size) - nothing
b) Radius 9,000 - 11,000 km (45-55 times Mimas' size) - nothing
c) Radius 11,000 - 13,200 km (55-66 times Mimas' size) - nothing
d) Radius 13,200 - 15,600 km (66-78 times Mimas' size) - nothing
e) Radius 15,600 - 18,200 km (78-91 times Mimas' size) - nothing

Ice Giants
Note: Gets gaseous from here on.
a) Radius 18,200 - 21,000 km (91-105 times Mimas' size) - nothing
b) Radius 21,000 - 24,000 km (105-120 times Mimas' size) - nothing
c) Radius 24,000 - 27,200 km (120-136 times Mimas' size) - 2 objects (Uranus and Neptune)
d) Radius 27,200 - 30,600 km (136-153 times Mimas' size) - nothing
e) Radius 30,600 - 34,200 km (153-171 times Mimas' size) - nothing
f) Radius 34,200 - 38,000 km (171-190 times Mimas' size) - nothing

Gas Giants
a) Radius 38,000 - 42,000 km (190-210 times Mimas' size) - nothing
b) Radius 42,000 - 46,200 km (210-231 times Mimas' size) - nothing
c) Radius 46,200 - 50,600 km (231-253 times Mimas' size) - nothing
d) Radius 50,600 - 55,200 km (253-276 times Mimas' size) - nothing
e) Radius 55,200 - 60,000 km (276-300 times Mimas' size) - 1 object (Saturn)
f) Radius 60,000 - 65,000 km (300-325 times Mimas' size) - nothing
g) Radius 65,000 - 70,200 km (325-351 times Mimas' size) - 1 object (Jupiter)

The next section above that includes Puffed Planets and Brown Dwarfs present in some other systems, but also already small stars (smallest Red Dwarf measured at 417 times Mimas' radius).

And yes, there is a system to the above numbers. A pretty easy one.

[kato]

Granted, I'd say any such claims are highly dubious

The two scientists named are astrobiologists who are outspoken panspermia proponents. Wickramasinghe in particular is known for claiming that about every disease pathogen on Earth must have been delivered by meteoroids from space. Neither of them has anything to do with the Rosetta mission.

The Torygraph has dared to ask some British members of the mission team their opinion on the matter:
http://www.telegraph.co.uk/news/science/space/11720871/Alien-life-unlikely-on-Rosetta-comet-say-mission-scientists.html

Edit:
This may be of interest, it's by those two guys: http://www.buckingham.ac.uk/wp-content/uploads/2014/12/Rosetta-images-of-Comet-67P-Churyumov%E2%80%93Gerasimenko-2.pdf
Not commenting the scientific quality, or whether this only contains conjecture.

[ANS Kamas P81]

Either way it's still bloody interesting - just what IS the stuff, especially in the presence of organics detected officially back in November?

[Sabelkatten]

My guess would be simple light hydrocarbons, with a smattering of heavier simple organics. I'm not a chemist, but it seems likely to me that such could be hidden in/under the ice and start boiling up now that it's getting closer to the sun.

Still, even if it's nothing more spectacular than that it's extremely interesting. And if they find something like amino acids? I bet the next probe won't have any problems with funding! :D

[worktroll]

Organics in space is nothing new - there's billions of tons of ethyl alcohol in most nebulae. Just a matter of having the right precursor elements, some sunlight, and a few aeons of time. And I'm completely open to material from meteors, etc. giving some kick-start to the development of amino acids & simpler proteins.

But Hoyle and Wickramasinghe do themselves and the concept of panspermia few favours by their fanboyism. And like a too-ardent Davionista, end up making people turn away from the kernel of truth that may be there.

I still like Larry Niven's explanation for how most of his aliens in our neighborhood can not only co-exist in the same environment, but also be edible to each other. his model? There was a precursor race, who seeded reducing-atmosphere worlds with algae & bacteria to "race-form" them. That race then died. Billions of years later, you've got a whole load of worlds based on similar biological building blocks, but with totally separate evolutions.

[ANS Kamas P81]

Ah yes, the Thrintun Chow Hall.  Bless the Tnuctipun.

[worktroll]

And other scientists call shennanigans ...

http://time.com/3947237/philae-microbial-alien-life/#3947237/philae-microbial-alien-life/

[rebs]

Reports were too hopeful and shiny-bright with enthusiast sensation.  I could see it as possible, but it's going to take true study and not wishful thinking to prove it.  I've had a real crash course of that with all of the Extra Solar Planet stuff that I've read into.  The scientists and the reporters are not on the same page very often.

[ANS Kamas P81]

The scientists and the reporters are not on the same page very often.

Kanye called, he' s really happy for Philae and will let it finish, but Kohoutek is one of the best comets of all time.

[rebs]

Kanye called, he' s really happy for Philae and will let it finish, but Kohoutek is one of the best comets of all time.

I heard something about that!  He almost bought it in partnership with Master P, because word with the 20 and under crowd has it that Philae's superior to Nike in every way, but just doesn't have the street cred and name recognition that Adidas or Reebok have.

[worktroll]

O. M. F. G.



May not be planets ... but they're worlds ...

[rebs]

Glory.  Five million miles to go, and then we'll pass what truly was the boundary of the Sun's planetary system for many of us since birth.

[ANS Kamas P81]

Image lacks southern hemisphere as it's opposite the probe at the moment, we'll get a better look there once New Horizons passes.  But damn if that black splot isn't perfectly on the equator.  It's too perfect for me; I'm betting that that's the result of an impact event that gave Pluto a spin - the direction of orbit is east-to-west like Earth, so the trail of debris and any immediate followup impacts (see Jupiter v. Shoemaker-Levy 9, 1994) would fall in that same perfect pattern.  Seems to validate the Charon impact hypothesis; hopefully they can get some spectral analysis with whatever's onboard to see if the black material matches Charon - or something else.

[Wrangler]

Amazing.  :o

I can't await until they the New Horizon finally does it's pass.  It's too bad they won't be able stay long to investigate.

[Sabelkatten]

Anyone knows the delta-v of a Earth-Pluto Hoffmann transfer, and if it's achievable by a nuclear-powered ion drive?

I'm thinking that if the black stuff Philae saw turns out to actually be complex hydrocarbons Pluto is really a prime target for a mission to find out more about (pre)life in the Oort cloud. :)

[kato]

3 km/s delta-v on a 80-year Hohmann orbit. 5 km/s for 30 years.

67P/C-G didn't come from the Oort cloud, but from the Kuiper Belt. Entirely different reservoir. It has also spent the last couple billion years within about only a few AU from the sun (and since 1959 hasn't gone past Jupiter's orbit).

[rebs]

Courtesy of NASA, we have Pluto with geographical features of seemingly geologic origin.

[worktroll]

By definition, wouldn't you not get tidal stresses from a tidally locked binary?

I love how the universe constantly confounds our expectations, in amazing ways. The nitrogen geysers on Triton were wild enough.

[Sabelkatten]

3 km/s delta-v on a 80-year Hohmann orbit. 5 km/s for 30 years.

67P/C-G didn't come from the Oort cloud, but from the Kuiper Belt. Entirely different reservoir. It has also spent the last couple billion years within about only a few AU from the sun (and since 1959 hasn't gone past Jupiter's orbit).

Bugger... That's what I get from going off ten-year-old memories. :P

Really low delta-v requirements, thought. Can that really be correct? Even considering the flight time? ???

[Øystein]

Pluto is, and always has been, a planet. That some dorky nerds at a convention decided to change that doesn't alter the facts. :P :D

[Maingunnery]

Pluto is, and always has been, a planet. That some dorky nerds at a convention decided to change that doesn't alter the facts. :P :D

Meanwhile Eris laughs at Pluto.  ;)

[rebs]

By definition, wouldn't you not get tidal stresses from a tidally locked binary?

I love how the universe constantly confounds our expectations, in amazing ways. The nitrogen geysers on Triton were wild enough.

Absolutely fascinating.  Tidally locked, and just receding from its closest approach to the Sun. From what we've already witnessed, the last 4 billion or so years seem to have been filled with plenty of "normal" activity for this sadly maligned planetary body.

Turns out Pluto will not be very different at all form the artist renderings of its surface that were in the various books when I was a little and wide-eyed kid - a child who never even suspected that Pluto would or could be sacked from the roll of planets.

[ANS Kamas P81]

By definition, wouldn't you not get tidal stresses from a tidally locked binary?

You'd still get the stresses.  A point on Pluto closer to Charon's center of gravity (and vice versa) will still get pulled more forcefully than a point further away.  You won't get variable tides were there an ocean on Pluto, but you would get one hell of a permanent high tide.

3 km/s delta-v on a 80-year Hohmann orbit. 5 km/s for 30 years.

Well, we know we can build space probes to last (hello, Voyager!) so the idea of a hundred-year-long science mission is fascinating.  I wonder how hard it would be to organize a new Grand Tour, perhaps; at least the outer worlds.  Something to stay around a while at Neptune, Uranus, and Pluto, and do some real serious science in a three-way set of Cassini missions.

[kato]

The next Grand Tour alignment will take place around 2150 ;)

[rebs]

Most of the Trans-Neptunian objects of note are too far apart for their own Grand Tour.  So I would be in favor of several more missions like this one.  One to Eris, one to Sedna while it is so very near on its 1,400 year orbit.  Maybe one to Haumea or Orcus or Quaoar... 

I'm still in favor of freezing myself for a Grand Tour, though.

[kato]

At 700 million per pop that's gonna get pricy fast. For a couple billion we could just as well station a large telescope in say Uranus' orbit to watch the Kuiper Belt from half the distance...