Lifting the Veil On Pluto's Atmosphere 79
New submitter Pedro Braganca sends an update on the New Horizons mission to Pluto, now less than four days to closest approach. While we're waiting, NASA has published the best images of Pluto and Charon yet seen. We're starting to be able to make out surface details: A high-contrast array of bright and dark features covers Pluto's surface, while on Charon, only a dark polar region interrupts a generally more uniform light gray terrain. The reddish materials that color Pluto are absent on Charon. Pluto has a significant atmosphere; Charon does not. On Pluto, exotic ices like frozen nitrogen, methane, and carbon monoxide have been found, while Charon's surface is made of frozen water and ammonia compounds. The interior of Pluto is mostly rock, while Charon contains equal measures of rock and water ice.
A countdown to closest approach is present on the New Horizons mission page, as well as the raw image feed.
Frozen (Score:5, Funny)
Charon is about 750 miles (1200 kilometers) across, about half the diameter of Pluto—making it the solar system’s largest moon relative to its planet.
Sounds like someone at NASA is still not over Pluto not being a planet. Let it go... let it go...
Re:Frozen (Score:5, Funny)
Re:Frozen (Score:5, Funny)
but, but, Pluto identifies as a planet.
Are you saying that Pluto is a trans-planet?
Maybe it can get some cosmetic surgery, oops sorry 'planetary status reassignment surgery'.
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Uhh, these don't look like planets:
http://pluto.jhuapl.edu/soc/Pl... [jhuapl.edu]
But if it feels inside like all its life its really been a planet, who are you to judge. Insensitive clod!
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Uhh, these [kinja-img.com] do.
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Hell, even Pluto wants to be a Kardashian gal? You'd think traveling that far out could get away from all that crap.
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Charon is about 750 miles (1200 kilometers) across, about half the diameter of Pluto—making it the solar system’s largest moon relative to its planet.
Sounds like someone at NASA is still not over Pluto not being a planet. Let it go... let it go...
No issues. Read it as "... [dwarf] planet." and everything is ok.
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The only place a moon is a planet should be astrology, and fuck astrology.
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Pluto is called a dwarf planet. Your other points are non-problems. Yes, the planets that have been smashed up? They are no longer planets. Do you want to call the entire asteroid belt a planet just because it may have been one in the past?
Giving similar objects different names in context is not strange to science. Do you also complain about the difference between meteor, meteoroid and meteorite? They literally are the same object but at differen
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By the new definition of planet, the Earth is technically not a planet, nor is Jupiter, as they have neither of them cleared their orbit. The Earth has small objects in its orbit, and Jupiter has the trojan asteroids. So that is two fewer planets, that should make the astronomers that redefined planets more happy. Since it was a union of astronomers (star studiers) that changed the definition, and a small percentage of them at that, why do we listen to them, when planetary scientists such as the guy in c
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While we all like to think we can rationally debate things based on one phrase, the reality is the definition is a bit more precise than that one sentence. Don't judge a criteria by its headline.
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And no, it doesn't ignore extrasolar planets or wandering planets. They'll get a category of their own when we find them. Like how adding the word "dwarf" to Pluto-class objects. There is absolutely NO trouble to add the word "extrasolar", for exa
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If you think 100% of a planet's orbit needs to be cleared, roundness doesn't work any better. Earth has mountains, so it's not completely round, so it's not a planet!
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Moons don't orbit the Sun.
We should just call Pluto SOL-9. Earth is SOL-3.
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Since the center of gravity between the two isn't within Pluto (or Charon), it isn't a moon. So NASA, of all people, got that wrong too.
NASA, of all people, don't actually use the center of gravity thing as a criterion for planet-ness or moon-ness. Neither does the IAU (according to them, Charon is officially a moon of Pluto). It's a popular proposal, but that's all it is, and it has its faults.
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It is just a person using the most convenient terminology.
I think we all understand perfectly well that a planet is, by established tradition, a very large object (by human measures) that orbits one or several stars, that has been shaped into a ball by its own gravity and that is ot a star itself. The use of the word "planet" in "dwarf planet" supports this point.
It is probably fine if different people use different lower size limits for what qualifies as large enough to be a proper planet. All that amounts
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It's a "binary dwarf planet system" (perhaps "multi-" if you add the other moons.) Sorry, but still no capital "P". Deal.
Enjoy the show regardless. Both are interesting worlds even if they were classified as "snarfpukers". They are beautiful worlds.
Premature (Score:2, Interesting)
There is little point in commenting on this stuff for the next few days. Just enjoy. Pluto is getting very big in New Horizon's field of view. The book on Pluto will be rewritten every few hours now. Strange to comment on the atmosphere which we cannot see, when terra incognita lies before us.
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It's a plot to sell higher quantities of "updated" textbooks. "Oh rats, my book only covers up to 3 days out. You have 2 days out, and that day is on the exam."
By the way, isn't the probe to be going into "silent mode" soon? It lacks the ability to point instruments and its main antenna independently (as Voyager had). Thus, to aim its instruments it has to stop talking to Earth. There is supposed to be a "final contact" before closest approach where the probe in incommunicado for a few days, storing data in
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Flyby. New Horizons is the fastest object ever launched. It is traveling at such speed that Pluto will barely deflect its course.
Not the fastest (Score:4, Informative)
New Horizons is the fastest object ever launched.
No it is not [wikipedia.org]. Not even close to the fastest object we've ever launched. That honor goes to the Helios-A and Helios-B probes which traveled about 70km/s. Much faster than the 16km/s of New Horizons.
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Heliocentric velocities don't count. I should have said this:
https://en.wikipedia.org/wiki/New_Horizons
New Horizons was launched on January 19, 2006, from Cape Canaveral, directly into an Earth-and-solar-escape trajectory with an Earth-relative speed of about 16.26 kilometers per second (58,536 km/h; 36,373 mph); it set the record for the highest launch speed of a human-made object from Earth.
Still not the fastest (Score:5, Interesting)
New Horizons was launched on January 19, 2006, from Cape Canaveral, directly into an Earth-and-solar-escape trajectory with an Earth-relative speed of about 16.26 kilometers per second (58,536 km/h; 36,373 mph); it set the record for the highest launch speed of a human-made object from Earth.
Still probably not correct. I refer you to the manhole cover [wikipedia.org] over the Pascal-B nuclear test. Basically we unintentionally (maybe?) made a nuclear powered potato canon. (which is AWESOME) The manhole cover was estimated to have been launched at 41,000mph - possibly being vaporized in the process.
Lower bound (Score:2)
Your link states 41 mi/s which is equal to 147600 mi/h. And since it was never measured exactly, it couldn't set a record.
Typo. Forgot the 1 in front. And yes it CAN set a record because we can very clearly set a lower bound for its speed. Since it was only in the screen for one frame and we know how much distance it had to cover at minimum in the time between frames we know the lower bound of the speed with good certainty. Might be faster but it can still set a record because nothing has gone faster than its lower bound.
Still slower (Score:2)
The unassailable world speed champion is another US spacecraft, the Galileo Atmosphere Probe. It plunged into Jupiter's atmosphere at 47km/s.
That's still slower than the manhole cover (66km/s) and the Helios probes (70km/s)
Re:Flyby or Orbt? (Score:4, Informative)
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Delta-V [wikipedia.org] isn't a rocket. (You might be thinking of Saturn V [wikipedia.org].) Delta-V is change in velocity: in this case, how much the spacecraft would have to slow down in order to enter orbit instead of just flying past.
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He meant either a Delta IV or an Atlas V, the heaviest rockets available in the US today.
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My bad; Tomhath was referring to either a Delta IV or an Atlas V and making two errors in the process, the OP was talking about delta-V as in speed change. Serves me right for answering before reading the complete thread.
Re:Flyby or Orbt? (Score:4, Informative)
The delta v relative to Pluto is 11 km/s, which is not a whole lot in and of itself. My understanding is that fuel boil-off during the 10 years of transit to Pluto makes it very difficult and expensive to bring along enough fuel for a retro burn to put a spacecraft into orbit around Pluto.
It would have been pretty awesome to have an obiter that could zip around Pluto and Charon and do observations. Maybe next time.
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The delta v relative to Pluto is 11 km/s, which is not a whole lot in and of itself.
On the contrary, 11 km/s is huge! The Space Shuttle Main Engines [wikipedia.org], one of our most efficient rocket engines, has an Isp of 4.436 km/s. By the rocket equation [wikipedia.org] this means that, to change velocity by 11 km/s using this engine, a spacecraft would need a ratio of wet mass to dry mass of exp(11/4.436) = 11.9. In other words, to stop the New Horizons probe at Pluto, we'd need to have sent along an extra 10.9 times its mass in fuel. And that's ignoring the mass of the engine and tankage, which makes things worse
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Yeah, it is fairly fast, but as your calculations show, a 500 kg orbiter traveling to Pluto in 10 years is not unthikable using chemical rockets and the current budget levels of NASA. The only parameter that makes it impossible is the cost of launching and assembling stuff in orbit.
You would be able to do a mission like that within the current budgets if there was a 20x drop in cost per unit of weight to orbit. That is assuming that you can build a rocket stage that can start (and/or restart) after 10 years
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There was some discussion of using what is eupemistically called "lithobraking" to put a probe down on, or more accurately in, Pluto's surface. Apparantly you really can make a probe that has a reasonable chance of still sending back useful science after hitting Pluto at 15 km/s or so.
For the anime fans - (Score:2)
Unfortunately, the Gamilon advanced planet bomb base on Pluto is hidden with a concealment field, so it is unlikely the New Horizons probe will be able to provide targeting information.
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Fortunately, we should be able to see the tunnels of the Bugger's forward operating base. For those of us that are Sci-fi fans.
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If it had 1/50th the resolution, maybe. 1/5th isn't much of a difference. Downsample the B&W image to 1/5 and you'll still see some detail, and not just a one-colour blob.
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Having said that, the colour was gathered at an earlier time, so may be even lower resolution.
Pluto (Score:2)
Very, very cool.