Suddenly, It Seems, Water Is Everywhere in Solar System
nytimes.com
nytimes.com
Furthermore, that chart is likely computed via a direct Hohmann transfer, which is one of the most efficient transfer maneuvers available. It also will take a lot longer.
For practical human travel to destinations farther way, you need to perform the so called "star wars maneuver", which is going essentially from A to B in a more or less straight line, which will cost a LOT of delta V.
True, but we could throw the big ship with all the supplies into a flight path that gains a lot of momentum around the inner planets and intercept it with a much smaller craft only loaded with enough fuel to get the astronauts to the transit ship (and back, if necessary).
It's at least 13 months to get to Jupiter for a probe, and reasonably much longer for a man-rated craft.
Mars is the next step in humanity's long term (hundred of thousands of years) survival. If we ever intend not to be at the mercy of gravity, we have to get off earth. We've been to the moon, which is gravitationally constrained to earth, and is only a three day journey (with many chances for safe aborts). We've conquered LEO and now know more about our planet than we could have dreamed up 20 years ago. Mars is a completely different challenge, and by going to Mars we'll develop the first bits of technology that will help us off our deathtrap of a cradle.
These two missions can coexist. We haven't developed the technology to send humans that far out into the solar system so we should continue to send probes.
That being said I don't think our solar system contains a more advanced being than humans. But what life, in some form, demonstrates is that it is possible, in some place very far away, there are living beings as advanced or more than we are. I would really love to be alive to meet them.
I can't imagine there would be any real debate over that point.
Assuming that they are benign and non threatening but I wouldn't take my chances. I dont hope for this.
Earth has a huge "ocean" deep in its mantle, but it's inside rocks. http://www.livescience.com/1312-huge-ocean-discovered-earth....
It avoids most genre cliches, apart from the very ending maybe.
Yeah, by being fully made of those. [SPOILER ALERT]
* lack of crew psychological cross-matching
* some ludicrously exoggerated hydrazine drama
* chloroplast-equipped organisms in the environment which ambient light spectrum is slightly inclined towards gamma radiation (not to mention the meat-packed space vessel itself, brightly shined up by very same light)
* _one_ central computer with sole purpose to be heroically repaired on the _outer_ shell of the vessel (you see, no EVA - no drama)
* (mentioned ending) transferring at least tens of gigabytes from Europe to Earth in a matter of seconds (via that special hero-driven central computer) despite being unable to establish uplink for past several months already due to the broken trasmitter (of course, unreserved)
---
Well, I understand that this is just a movie, but look, why not to put it in agreement with some common sense?
Exoggerated drama (i.e. dramatic action out of nothing or due the course of highly regulated procedures (eg. EVA)) is harder to evaluate: sometimes that drama looks quite plausible. Nevertheless, action sci-fi without some sort of team member sacrificion/unexpected death is hard to imagine, at least for me. Hell, it is not even specific to sci-fi: just take a look into any action movie out there - pretty high chances to become a witness of the dramatic death.
Very frivolous treatment of the laws of physics in general. I am pointing out that instantaneous information transmission specifically. Well, pretty much of cliche either, isn't it?
Stupid reasons for "heroicity". Are you a script writer in a search for the rationale to balance around the case of dramatic death of one or more characters? Director struggling with producers demand for fancy attention-binding activity you might be. What to do? Easy! Just place some important peace of equipment in a morbid place and there you go - engineering have been favored out by thrill.
Life. Remember that in "Babylon 5" most of aliens were anthropomorphic? Well, 90th there were, no fancy CG, and, besides, convergention one may say, right? Second decade of XXI century, Wikipedia is here and accessible in a matter of keystrokes. Why not chemothrophs, why?! Although, phototrophs could be plausible even in a shady world, convergention one may say...
http://www.nasa.gov/content/titan-submarine-exploring-the-de...
http://www.ted.com/talks/bill_stone_explores_the_earth_and_s...
[1] http://www.stoneaerospace.com/
[2] http://www.wired.com/2012/04/bill-stone-laser-powered-europa...
- oxygen just as readily binds to everything else, to form metal oxides (the well-known rust on Mars) or silicates (rock) or just CO2 (Venus)
- hydrogen is so light it readily escapes into space from anything smaller than Earth
- H2O as solid ice is common anyway, but not as liquid water, which is more relevant for potential habitability and life. The conditions for the liquid phase of water are a remarkably narrow area on the phase diagram. That we have found in few locations, and it's news when a new such place is discovered.
http://d32ogoqmya1dw8.cloudfront.net/images/research_educati...
Now, if there was a single planet that had both ice and vapor water, and that planet had an atmospheric pressure of greater than 0.006 atm, then I agree that there must be some liquid water somewhere on that planet. But ice and vapor on a single planet with a sufficient atmosphere is a much higher bar to clear than two totally separate places that combined have both ice and water vapor.
What we've been learning is that there is water ice in some places we didn't necessarily expect it before (such as in the form of permafrost underlying much of the Martian surface) and most importantly that liquid water is not as uncommon as we once thought. Liquid water is what's most interesting from the point of view of looking for environments that can support life forms. Previously we thought that the presence of liquid water required not only the presence of water as a material but also overall planetary temperatures in a temperate range, the so called "habitable zone". Which, as it turns out, is a fairly narrow zone. But we've learned that there seem to be numerous circumstances that allow the existence of substantial quantities of liquid water in conditions that otherwise would not support it. Europa, for example, has frigid surface temperatures (150 to 200 degrees C below freezing) but it has a sub-surface ocean due to tidal interactions with its neighbors. That sort of thing seems to be much more common than we knew previously.
... except California.
However, I get the cringes every time an article about space exploration uses those atavistic units like Royal Hangnails (length), Princely Bladders (volume), Regal Farts (speed) and Fornicating Fever (temperature) for measurement. Hasn't the metric system arrived yet on planet USA?
It is strange now that I think about it that we have imperial measurements for milk but metric measurements for sugary drinks/beer.
Other than 1 and 2 liter bottles of pop, I can't really think of any time I would buy pop or beer using the metric system.
In this respect (partial antiquation in the wake of unit redefinitions) liters have something in common with the quart.
http://isomorphism.es/post/3767526267/fahrenheit-versus-cels...
Metric only wins in my book because it is much easier to convert units (there are no magic numbers for conversion factors). However I'd laugh at anyone who suggest metric is better because people inherently internalise it better, just as I laugh at people who suggest the same for imperial.
The US should switch, there are no legitimate arguments against it except perhaps [short term] costs. Certainly not "because F is easier to understand." It is only easier because you grew up with it and are used to it...
I disagree. Once you've been taught a base ten counting system, units that change based on orders of magnitude is very easy to understand. Since almost everyone has a base ten counting system internalized, metric is MUCH easier.
Don't get me wrong, I like the metric system. But US Customary units aren't that hard to deal with. Seriously, we're software developers, we don't memorize shit. We create type definitions and routines to convert between them.
The same arguments you make for why it's not that big of a deal to switch are the same arguments for why it's not that big of a deal to not switch.
That's not true at all. The metric system is more intuitive because it is a Base 10 system, which is very intuitive and natural for humans because we have ten fingers. Base 10 also makes things a lot easier because calculations are simply a matter of adding/removing zeroes/decimals.
And base 12 is way more divisible.
Shit happens. Want me to point to the Beagle probe? Space isn't easy.
Look at the Araine 5. Unit conversions had nothing to do with a computer saying "gimbal an engine 90 degrees".
I'm sorry but this canard of two units being the problem is missing the entire point.
Its an engineering issue and management failure. Just like the space shuttle O rings before them, space is hard. Distilling things down to "america should have used metric cause reasons" is trying to pass off complex problems with bite sized quotes. The only issue is it is wrong.
Sure, the units issue was the root cause, but the resulting navigation errors should have been acted upon. They were noticed ("The discrepancy between calculated and measured position, resulting in the discrepancy between desired and actual orbit insertion altitude, had been noticed earlier by at least two navigators, whose concerns were dismissed."), but the issue wasn't acted upon. This is a management and budget problem.
Even if the units are given as SI, there are always interface issues -- which coordinate system to use, where the origin is, does z point up or down, degrees or radians. It can be hard to appreciate unless you have had experience with hard-to-find failures due to subtle numerical problems.
As you say, space is hard.
And what good is a system of measurement that you can't use to bamboozle customers? ("That's not an ounce, ma'am, that's a Troy ounce...")
If we move to anything, it's going to be Donald Knuth's Potrzebie system (see http://en.wikipedia.org/wiki/Potrzebie). It seems more well thought out than most.