×

Announcing: Slashdot Deals - Explore geek apps, games, gadgets and more. (what is this?)

Thank you!

We are sorry to see you leave - Beta is different and we value the time you took to try it out. Before you decide to go, please take a look at some value-adds for Beta and learn more about it. Thank you for reading Slashdot, and for making the site better!

Astronomers Find What May Be the Closest Exoplanet So Far

Soulskill posted about 4 months ago | from the launch-invasion-fleet dept.

Space 89

The Bad Astronomer writes: Astronomers have found a 5.4 Earth-mass planet orbiting the star Gliese 15A, a red dwarf in a binary system just 11.7 light years away (PDF). Other exoplanets candidates have been found that are closer, but they are as yet unconfirmed. This is more evidence that alien planets are common in the galaxy.

Sorry! There are no comments related to the filter you selected.

OK Another one (1)

Geek Hillbilly (2975053) | about 4 months ago | (#47785119)

OK is it another "Hot" Jupiter or is it a rocky world in the habitable zone? Might just be Quonos.(Klingon Home World)

Re:OK Another one (4, Informative)

i kan reed (749298) | about 4 months ago | (#47785161)

5.4 earth masses puts it at about 1/3rd of a Neptune or a tiny fraction of a Jupiter or a Saturn.

It might even have a thin enough atmosphere to not completely crush a human.

Re:OK Another one (4, Funny)

bill_mcgonigle (4333) | about 4 months ago | (#47785249)

It might even have a thin enough atmosphere to not completely crush a human.

If the gravity isn't too high, we can engineer around all the rest. Ought to be just fine for bots if the solder doesn't flow at its temps. A giant pot of natural resources at 11LY is very exciting for colonials!

Re:OK Another one (1)

Anonymous Coward | about 4 months ago | (#47785257)

BAHHHH AHahahahahaaa!!! AHh hahahahahaaaa!!! Hoo boy!!

You almost had me, I thought you were serious!

Good one!

Re:OK Another one (1)

i kan reed (749298) | about 4 months ago | (#47785287)

Yeah, actually let's figure out the moon or mars first. Hell, Venus is probably an easier technological challenge.

Re:OK Another one (0)

Anonymous Coward | about 4 months ago | (#47785543)

Venus near the surface, is hotter than the sun-side of Mercury (by our estimates). How about them asteroids?

Re:OK Another one (1)

SternisheFan (2529412) | about 4 months ago | (#47786031)

How 'bout them?

http://online.wsj.com/articles... [wsj.com]

A few companies, such as Planetary Resources and Deep Space Industries, have formed with the goal of mining asteroids. Why asteroids? Because it currently costs several thousand dollars per pound to put anything from Earth into low-earth orbit. Asteroids are probably made of all the ingredients necessary to live in space, including water. These companies intend to supply the raw materials to support an entirely new space economy.

Water will be particularly important. Beyond sustaining human life, water can shield people from harmful radiation and serve as fuel for spacecraft. It can be separated into its two components to generate energy or be heated with focused energy from the sun.

These infant asteroid-mining companies and their investors are taking on enormous risks to develop technologies to extract usable resources in space. The hitch? There is currently no legal guarantee they will be able to profit from the resources they mine. The ownership of resources mined in space is legally murky.

http://www.spacedaily.com/repo... [spacedaily.com]

Re:OK Another one (1)

peragrin (659227) | about 4 months ago | (#47786409)

There is another hitch too the 3-10 years it takes to get to the target mine before you can setup operations.

Until we figure out faster space drives even mars is a long shot. The best bet to start off with is finding water and oil on the moon (oil to give a reason to go there)

Re:OK Another one (0)

Anonymous Coward | about 4 months ago | (#47790151)

I am not sure that the time taken to set up a mine would be an issue. I have not done any research so I may be full of crap, but I would think it takes a few years for any large mining operation to start producing ore and making a profit. 10 years seems a little too long to wait, but 3 years seems reasonable. I also think it is about time we stopped looking for the fast buck and started to plan 10-20-30+ years into the future.

Re:OK Another one (0)

Anonymous Coward | about 4 months ago | (#47790159)

Wow! LOL.

Do you know where oil comes from? Why would you expect to find oil on the moon? Just asking.

Water... probably. Oil? hahahahaha. Never.

Re:OK Another one (1)

butalearner (1235200) | about 4 months ago | (#47786189)

Venus near the surface, is hotter than the sun-side of Mercury (by our estimates).

Two words: cloud city [wikipedia.org] .

Sounds preposterous, I know, but it's almost certainly easier than colonizing the first completely habitable earth-like exoplanet (and the article actually makes it sound more plausible than the name implies). That's not to say we should stop looking for them, of course...far from it. Those are the best chance we have to find extraterrestrial life, intelligent or otherwise.

Re:OK Another one (1)

RockDoctor (15477) | about 4 months ago | (#47792553)

A giant pot of natural resources at 11LY is very exciting for colonials!

If only Nature hadn't put it at the bottom of a 5.4 Earth-mass gravity hole. that's almost as malicious as your average god.

Re:OK Another one (3, Interesting)

mark-t (151149) | about 4 months ago | (#47785379)

As a larger planet, however, since force of gravity is inversely proportional to the square of the distance, the surface gravity of a world otherwise equivalent in density to another ends up rises linearly with the diameter of the planet. If it is of similar composition to earth, then 5.4 earth masses would make it cbrt(5.4) times the size of earth, or roughly 1.75g at the planet's surface. Assuming that the atmospheric density is comparable to earth's (possible, even with greater gravity if the atmosphere itself is proportionally thinner), then this is theoretically survivable by human beings for short periods, or even prolonged ones if they were able to acclimate to the increased gravitation pull gradually, over a span of several years, giving time for skeletal tissue to build up and strengthen the body's structure to survive the increased tension.

Re:OK Another one (1)

i kan reed (749298) | about 4 months ago | (#47785387)

But, of course, we don't know that the density of the planet is comparable to earth.

Re:OK Another one (4, Informative)

ShanghaiBill (739463) | about 4 months ago | (#47785571)

But, of course, we don't know that the density of the planet is comparable to earth.

It is probably less. Of all the planets and spherical moons is our solar system, no other has a density as high as Earth. Earth's density is 5.5 gm/cc. The moon is 3.3. Mars is 3.9. If this planet has a density similar to the moon, its surface gravity would be about the same as Earth's.

Re:OK Another one (1)

pitchpipe (708843) | about 4 months ago | (#47786183)

If the surface gravity were about the same as the Earth's, wouldn't that mean that its atmospheric pressure at the surface would be about the same also. After all, it's gravity holding the gas down, and technically the atmospheric pressure is the weight of the gas above that point. Assuming the gas is trapped to the planet by the gravity, then you might have about the same amount of gas trapped above a point by a similar amount of gravity.

I'm just speculating though.

Venus (4, Informative)

luis_a_espinal (1810296) | about 4 months ago | (#47786683)

If the surface gravity were about the same as the Earth's, wouldn't that mean that its atmospheric pressure at the surface would be about the same also. After all, it's gravity holding the gas down, and technically the atmospheric pressure is the weight of the gas above that point. Assuming the gas is trapped to the planet by the gravity, then you might have about the same amount of gas trapped above a point by a similar amount of gravity.

I'm just speculating though.

No. Atmospheric pressure is not simply a function of gravity. It is more a function of how much stuff there is in the atmosphere.

Consider that Venus' surface gravity is 0.904g wrt to Earth's (1g). And yet Venus's atmospheric pressure at the surface is 9.2 Megapascals whereas Earth's atmospheric pressure is 101.325 kilo-pascals (or 0.101325 Megapascals).

That is, even though Venus gravity is 90.4% that of Earth, its atmospheric pressure is 92 times that of Earth.

Re:OK Another one (1)

jafac (1449) | about 4 months ago | (#47785817)

Okay, but for example:
I am pretty overweight, but I'm in pretty good physical condition. I currently weigh 180 lbs. On this planet, I would weigh 315 lbs. That's like carrying 135 lbs of extra weight. If I'm backpacking, I carry anywhere from 25-35 lbs total, and I can "go" all day like that. I get pretty wiped out, but it's something I can adjust to, over time. I've hiked at 70 lbs, carrying equipment for other "less capable" people. That's really about my limit. This seriously cuts my hike range from about 15 miles in a day (max, really humping hard) to about 5-7. After a day like that, I'm fucking beat. And that is where I can take this pack off, and set up camp, cook, eat, sleep. I could pack 135 lbs, but I wouldn't get far, and I'd probably hurt myself trying.

When I train, I train with a pack that starts at about 10 lbs, and I ramp up over a few weeks to 40 lbs. And that is gradual enough, to avoid injuries, while building-up strength. And this increases my capacity and performance, but this takes weeks. (and as I get older, it gets much harder).

I see absolutely no way in hell I'm going to deal with an extra 135 lbs of weight, 24-hours a day. I'm not going to "build-skeletal tissue" or strengthen my body's structure. What will happen, physiologically, is I'll "survive" (minimally) maybe a day. My joints will get beat all to hell. I will be too sore to move for another few days of immobility. If I stayed on the surface, it's pretty likely I'd not recover.

I think that a "1.25 g" planet might be survivable for short periods. And this level MIGHT be enough for "physical toughness" to develop (over time), given a proper training/rest regimen, proper nutrition, and medical assistance with things like testosterone, HGH, and whatever other "black-magic" stuff that the pro athletes are taking.

I'd also tip my hat to probably the top-10% of the genetic bell-curve; those individuals who have rare, natural gifts of athletic ability, and while they are in their prime years of life, to MAYBE be able to adjust long-term to 1.5 g.

Re:OK Another one (1)

mark-t (151149) | about 4 months ago | (#47786335)

*YOU* might not... but your great-great or great-great-great grandchildren might... I am presuming that you'd be living on a generational spaceship where the gravity can be slowly modified so that by the time they arrive, they would be fully acclimated to the higher gravity.

Re:OK Another one (1)

I'm New Around Here (1154723) | about 4 months ago | (#47786411)

Unfortunately, people on this site that specializes in technology, don't actually believe that generational spaceships are possible. Either now or in all of our future timeframe.

I tried to make a similar argument about 2 months ago, and got nothing but grief for postulating such an idea.

Re:OK Another one (1)

neoritter (3021561) | about 4 months ago | (#47786877)

I'd think the question would be, if we can create a generational spaceship, what's the purpose of creating a colony on a planet we'd have troubles adapting to? Instead we'd just build an orbiting space station around the planet and mine it using robots.

Re:OK Another one (1)

Paul server guy (1128251) | about 4 months ago | (#47791245)

Unfortunately, people on this site that specializes in technology, don't actually believe that generational spaceships are possible. Either now or in all of our future timeframe.

I tried to make a similar argument about 2 months ago, and got nothing but grief for postulating such an idea.

Not true, there are many people who believe generational spaceships are possible, in the near term. The problem isn't the tech, the problem is the same for /all/ space projects.

Who's going to pay for it?

Re:OK Another one (0)

Anonymous Coward | about 4 months ago | (#47786783)

Maybe you can't.

I bet the military has different ideas about that however.

Re:OK Another one (1)

amicusNYCL (1538833) | about 4 months ago | (#47786187)

As a larger planet, however, since force of gravity is inversely proportional to the square of the distance, the surface gravity of a world otherwise equivalent in density to another ends up rises linearly with the diameter of the planet. If it is of similar composition to earth, then 5.4 earth masses would make it cbrt(5.4) times the size of earth, or roughly 1.75g at the planet's surface.

Doesn't that assume that the source of the gravity is a point at the center of a planet? Is that how planetary gravity actually works in practice?

Re:OK Another one (1)

I'm New Around Here (1154723) | about 4 months ago | (#47786423)

If you assume any sort of liquid core during the planet's history, then the heaviest masses would move toward equilibrium. That would tend to be at the center, since moving away from the center would usually be moving against more mass (and more gravity) than what it would be moving toward.

Re:OK Another one (2)

Rockoon (1252108) | about 4 months ago | (#47786579)

Doesn't that assume that the source of the gravity is a point at the center of a planet? Is that how planetary gravity actually works in practice?

For any collection of mass, if you are further from its center of mass than any part of that collection, then yes in 100% of the possible arrangements of that mass.

Also not commonly known is that when you are closer to the center of mass than any part of that collection, then you are 100% "weightless" in all the possible arrangements of that mass.

Re:OK Another one (1)

schlachter (862210) | about 4 months ago | (#47785815)

yeah, but probably no humans there to crush. you'd imagine the local species would have evolved to deal with the pressure.

Re:OK Another one (1)

Mister Liberty (769145) | about 4 months ago | (#47786311)

Pray tell, where would said human come from?

Re:OK Another one (1)

I'm New Around Here (1154723) | about 4 months ago | (#47786445)

He would come from an egg [photobucket.com] , of course.

Re:OK Another one (0)

Anonymous Coward | about 4 months ago | (#47789487)

Also 37% the size of Uranus. lol

Slate? (0)

Anonymous Coward | about 4 months ago | (#47785163)

I seem to only find this story on Slate. First we get the lovely story about the ipod touch bricking someone's arm. Now we get this fantastic story. Great.

Re:Slate? (1)

Java Pimp (98454) | about 4 months ago | (#47785353)

I'm confused. You do know it was the Slate article that debunked the BS ipod bricking the prosthetic story, right? Or did you not actually read that article?

Time to travel 11 light years (3, Interesting)

goombah99 (560566) | about 4 months ago | (#47785183)

traveling with a 1G acceleration:
1/2g t^2 = 1/2*11*3E8

so t = 3.3 years to half way. 6.6 years to go all the way and thus 13.2 years for the round trip.

Thus you could easily go there and come back in your lifetime.

Note that this is also Faster than light can make the round trip. However that is not any violation of relativity. THe people on earth would have aged a lot more than 13.3 years during your trip. But you would only have aged 13.3 years.

Re:Time to travel 11 light years (2)

war4peace (1628283) | about 4 months ago | (#47785221)

Now all you need is find a spaceship that could achieve this...

Re:Time to travel 11 light years (2)

goombah99 (560566) | about 4 months ago | (#47785259)

it's a matter of fuel with sufficient thrust to weight ratio (unless you want to start thinking about using the interstellar gases as the propellant--- that get's dicey because they will be approaching your craft at near the speed of light)

Re:Time to travel 11 light years (3, Informative)

i kan reed (749298) | about 4 months ago | (#47785279)

Teah, they call that "thust to weight ratio" you're referring to specific impulse [wikipedia.org]

Re:Time to travel 11 light years (3, Interesting)

goombah99 (560566) | about 4 months ago | (#47785495)

Let's see if I can work this out correctly;
First assume the spaceships weight negligibly different than the mass of the fuel. The thrust needed to push the weight at a steady 1g will be proportional to the mass of the ship at each interval of time. SO the rate of mass burn is proportional to the mass which means the mass is a decaying exponential.

M = Mo * exp( -g * time / thrust_to_weight )

If you think about this for a moment it becomes clear that any amount of mass would do since as the mass gets lighter it takes less fuel so the ship could go indefinitely at 1g. The problem is the assumption that the ship weighs nothing. so let's fix that.

dM/dt = -g*(M+Ms)/thrust_to_weight.

where Ms = mass of ship and M = mass of fuel.

I'm spacing on how to solve that equation so I'll approximate it by saying that until M = Ms we can mostly ignore the ship mass. therfore for a 6.6 year flight time the fuel required is about:

Mfuel = Ms * exp( g* (6.6 years)/thrust_to_weight )

Mfule = Ms * exp( +303,800,000/thrust_to_weight).

So you need a rather high thrust to weight ratio due to the coefficient in the exponetial.

Let the pillory for my "obvious" math errors begin!

Re:Time to travel 11 light years (1)

i kan reed (749298) | about 4 months ago | (#47785269)

Hypothetically, fusion powered Hall ion engines might be able to manage something within an order of magnitude of that, I think.

But of course, we'd need a lightweight fusion reactor that produces electricity without a boiler. Such a thing has been proposed as possible, but it's definitely not available yet.

Re:Time to travel 11 light years (0)

Anonymous Coward | about 4 months ago | (#47786029)

proton boron pinch? uses something similar to a cathode ray tube in reverse to decelerate the released charged particles. could pack a gigawatt of power production on something that only weighs about 10 tons. Compared to the amount of chemical fuel needed to get large spacecraft out of earth orbit, that is peanuts.

Re:Time to travel 11 light years (1)

I'm New Around Here (1154723) | about 4 months ago | (#47786489)

Compared to the amount of chemical fuel needed to get large spacecraft out of earth orbit, that is peanuts.

Remember, nothing says the ship must be built on and launch from Earth. Build it out by the asteroid belt, mine them for material, start the ship moving and time it to slingshot around Jupiter or Saturn, and use your engine of choice for the journey.

Re:Time to travel 11 light years (1)

Anonymous Coward | about 4 months ago | (#47785271)

Oh leave the children to their fantasies, they look so happy in their dreamworld.

Re:Time to travel 11 light years (1)

MRe_nl (306212) | about 4 months ago | (#47785373)

Is that a droud implant in your skull or are you just happy to see me...

Re:Time to travel 11 light years (2)

Katatsumuri (1137173) | about 4 months ago | (#47785383)

True. Finding interesting destinations and developing new propulsion methods are mutually complementary tasks. Both are important and can be done in parallel by people with different talents and interests.

Re:Time to travel 11 light years (1)

Overzeetop (214511) | about 4 months ago | (#47785857)

No you don't - just turn off the rockets and let it fall half way there (accelerating) under the other planets gravity, then turn around so that you slow down at the rate of earth's gravity pulling you back for the second half of the trip. All you need is the fuel to get to orbit and you're practically done.

*ducks*

Re:Time to travel 11 light years (1)

war4peace (1628283) | about 4 months ago | (#47786171)

Makes TOTAL sense :)

Re:Time to travel 11 light years (1)

confused one (671304) | about 4 months ago | (#47785347)

1. we don't have the technology to achieve that. 2. without some as yet to be thought of technology, the relativistic relative motion of the incident protons, even at 1 per cubic meter or so, would interact with the vehicle structure and create showers of particles, killing the crew.

Re:Time to travel 11 light years (0)

Anonymous Coward | about 4 months ago | (#47785421)

But the particle shower scene would sell it alone

Re:Time to travel 11 light years (1)

goombah99 (560566) | about 4 months ago | (#47785529)

Something I've wondered about is why we don't see more relativistic protons hitting earth or the ISS. Is the relative velocity of everything in the universe extremely low? I don't think so. So where are these missing showers on earth right now?

Re:Time to travel 11 light years (1)

wonkey_monkey (2592601) | about 4 months ago | (#47785695)

Something I've wondered about is why we don't see more relativistic protons hitting earth or the ISS. So where are these missing showers on earth right now?

Are they missing? Why would you expect more than we get?

Is the relative velocity of everything in the universe extremely low? I don't think so.

Why not? The relative velocity of most things nearby - the solar system, the Milky Way, Andromeda - is all quite slow relative to us, isn't it?

Re:Time to travel 11 light years (0)

Anonymous Coward | about 4 months ago | (#47786063)

http://en.wikipedia.org/wiki/Heliosphere
http://en.wikipedia.org/wiki/Earth%27s_magnetic_field

Re:Time to travel 11 light years (1)

confused one (671304) | about 4 months ago | (#47787555)

first of all, any high energy protons that come into the region around Earth are deflected by our magnetosphere. At worse, nothing happens. At best, you get pretty lights in the northern sky. Second, the particles aren't necessarily travelling at relativistic speeds, you are (when travelling at velocities approaching c). From your perspective, you're in a sea of relativistic protons even if they're standing still.

Re:Time to travel 11 light years (2)

QuantumPion (805098) | about 4 months ago | (#47785537)

Try plugging your trip into the Tsiolkovsky rocket equation [wolframalpha.com] . Assume the most theoretically advanced engine exhaust velocity. What is the required initial mass for your rocket? How many multiples of the mass of the entire universe are required for your rocket?

Re:Time to travel 11 light years (0)

goombah99 (560566) | about 4 months ago | (#47785577)

Right. I did a more relevant calculation of that here:
http://science.slashdot.org/co... [slashdot.org]

Re:Time to travel 11 light years (0)

Anonymous Coward | about 4 months ago | (#47785555)

The correct equation is c^2/g*(cosh(t*g/c)-1), not 1/2*g*t^2.
The correct half-way distance is 1/2 * 11.7 * 9.46e15 meters.

Re:Time to travel 11 light years (0)

Anonymous Coward | about 4 months ago | (#47785591)

Wrong or Citation please.

Re:Time to travel 11 light years (0)

Anonymous Coward | about 4 months ago | (#47785993)

Swallow a cactus or look for d = (c^2/a) [ch(aT/c) - 1] on this page [ucr.edu] .

Re:Time to travel 11 light years (1)

wonkey_monkey (2592601) | about 4 months ago | (#47785613)

Note that this is also Faster than light can make the round trip.

Not from the light's point-of-view!

http://www.convertalot.com/rel... [convertalot.com]

I put some numbers in and got almost exactly 4 on-board years for the half-way trip, so 16 for the round trip.

Re:Time to travel 11 light years (1)

Framboise (521772) | about 4 months ago | (#47785885)

Before embarking to such a trip you had better wait the confirmation of a planet around Alpha Centauri at 4.3 ly. Even if the already announced discovery turns out to be wrong, the probability that some planets exist in the Alpha Centauri system is large.

suspended animation (1)

schlachter (862210) | about 4 months ago | (#47785909)

people are forgetting that no one's going to be awake or likely aging during this flight. suspended animation will be required for a trip like this and likely possible in the not too distant future (100 yrs?).

so it doesn't really matter so much if it takes 13.3 yrs or 100 yrs.

the hardest part will be that people don't do well at funding and executing projects that last more than a life time. the organizations and countries and people that launch these missions will be long gone by the time the crew arrives. there's a high chance they won't even know the mission existed and will not have the (ancient) equipment to communicate with the crew.

Re:Time to travel 11 light years (1)

s1d3track3D (1504503) | about 4 months ago | (#47786061)

traveling with a 1G acceleration:

And where is such a craft? Our current fastest space shuttles go ~ 17,500 mph, at that pace, it would take over half a million years... (ref: How fast does a Shuttle travel [nasa.gov]

Re:Time to travel 11 light years (1)

amicusNYCL (1538833) | about 4 months ago | (#47786249)

Our current fastest space shuttles go ~ 17,500 mph

So what, a space shuttle is not an interstellar ship. The New Horizons probe is moving at around 36,000 mph, and that thing only has a 77kg fuel tank.

Re:Time to travel 11 light years (1)

Rockoon (1252108) | about 4 months ago | (#47786605)

And where is such a craft? Our current fastest space shuttles go ~ 17,500 mph

[whisper]hey moron, velocity is not acceleration[/whisper]

Re:Time to travel 11 light years (0)

Anonymous Coward | about 4 months ago | (#47798905)

he just needs to play more kerbal space program, then he'll understand.

Re:Time to travel 11 light years (1)

Applehu Akbar (2968043) | about 4 months ago | (#47787315)

You're talking speed, while Parent was talking acceleration. A ship to LEO takes about ten minutes to achieve orbital velocity, then no thrust after that. A ship to Leo (any star therein) could actually get there in a reasonable amount of time if 1G of acceleration could be maintained all the way to the midpoint of the journey and then kept up as deceleration the rest of the way. The big catch is the number of stars worth of fuel you would have to bring with you.

Re:Time to travel 11 light years (0)

Anonymous Coward | about 4 months ago | (#47786123)

Distance to travel 11 light years

FTFY

Re:Time to travel 11 light years (1)

amicusNYCL (1538833) | about 4 months ago | (#47786223)

so t = 3.3 years to half way. 6.6 years to go all the way

And exactly how fast would you be traveling once you made it there? What's the point of getting there when by the time you finish saying "we're here" you're no longer there?

Re:Time to travel 11 light years (1)

Rockoon (1252108) | about 4 months ago | (#47786623)

And exactly how fast would you be traveling once you made it there?

a speed of zero relative to the target

You seem to completely not understand the subject, which makes us wonder why you are posting. The second half of the trip is 1G deceleration.

Re:Time to travel 11 light years (1)

amicusNYCL (1538833) | about 4 months ago | (#47809971)

You seem to completely not understand the subject, which makes us wonder why you are posting.

"Us?" Do you have a turd in your pocket? Is Slashdot only for people who are 100% knowledgeable in all given subjects?

Snark aside, I read the original equation wrong. I didn't realize that the reason that the second half of travel was as long as the first half was because of constant acceleration switching directions. But that doesn't mean you need to be a dick about it. But, by all means, don't let me stop you from explaining how one would travel a linear distance of 11 light years in 6.6 years.

Re:Time to travel 11 light years (0)

Anonymous Coward | about 4 months ago | (#47787077)

Did you take into account having to do a turnover and decelerate @ 1G for arrival?

Re:Time to travel 11 light years (1)

Bratch (664572) | about 4 months ago | (#47787349)

This was the topic of "How the Universe Works" last night. Even if we figured out the propulsion system (fusion or anti-matter), and figured out a good way to maintain artificial gravity, we would still face the issue of being exposed to large doses of radiation. A simple coating to absorb the radiation wouldn't work because it emits the absorbed radiation in another form, which is still harmful. We would need some type of magnetic shielding similar to how the Earth is currently protected. They said that NASA is already working on the next generation heavy lift vehicles that could be used to construct a large craft in orbit. It's not going to happen in my lifetime, but eventually we will need to leave this planet.

Minimum mass (1)

Pausanias (681077) | about 4 months ago | (#47785231)

5.4 solar masses is m sin i, where i is the inclination of the orbit to the plane of the sky. Therefore, the mass could well be greater than 5.4 solar masses, and so it could be a neptune or in rare cases of close to face-on inclination have even higher mass.

This is a limitation of the radial velocity method, which was used in this detection; with transits (where you watch the star dim as the planet passes in front of it) you already know the inclination---it's 90 degrees to a high accuracy. So you know the mass once you have a transit and a radial velocity.

Re:Minimum mass (1)

Pausanias (681077) | about 4 months ago | (#47785245)

oops I meant earth masses not solar.

Could it be... (1)

whitroth (9367) | about 4 months ago | (#47785277)

Krypton?

                mark "it had to be asked"

ok, so, what now (3, Insightful)

confused one (671304) | about 4 months ago | (#47785391)

So close... and yet still a freeking impossible distance away.

Oh.. it's just 11 light years away. That's a small number, right? As much as I'd like to be able to say we have a "warp drive" or "jump drive" or something like that... at the moment 11 light years might as well be 11 million light years. it makes no difference to our ability to get there.

Re:ok, so, what now (1)

symbolset (646467) | about 4 months ago | (#47785425)

It took humans a million years to colonize the western hemisphere. Time is long.

Re: ok, so, what now (1)

tysonedwards (969693) | about 4 months ago | (#47785639)

You're off by a decimal place there in how long humans have existed on this planet.

Re: ok, so, what now (1)

Jason Levine (196982) | about 4 months ago | (#47785835)

Not if you factor in meddling by a certain mad man in a blue box. He makes the math go all wibbly wobbly.

Re: ok, so, what now (1)

tysonedwards (969693) | about 4 months ago | (#47785977)

If we're being fanciful, then we could just as easily say "it took humans 4 billion years and change to colonize the Western Hemisphere of planet Earth. The fact that they didn't for most of that is irrelevant." Or substitute 13 billion years instead and say "the fact that neither existed for most of that is irrelevant." The fact still remains that in cosmological terms, things have been around for a really, really, really long time in comparison to the minute instant that we as a species have existed, let alone been able to contemplate questions like how long we as a species have been around in comparison to the age of the universe!

Re:ok, so, what now (1)

vikingpower (768921) | about 4 months ago | (#47785985)

Nope. Not the western hemisphere, but rather the eastern. Humans came from Africa, which is in the half of the globe that has eastern longitude. From there, they spread to Asia and Europe, and from Asia to the Americas, the latter movement having been a rather recent event in human history ( less than 100.000 years ago ).

Re:ok, so, what now (0)

Anonymous Coward | about 4 months ago | (#47786015)

The western hemisphere already had every other life form in it. Space is utterly empty.

Is this difficult to grasp?

Re:ok, so, what now (1)

Markvs (17298) | about 4 months ago | (#47785671)

So close... and yet still a freeking impossible distance away.

Oh.. it's just 11 light years away. That's a small number, right? As much as I'd like to be able to say we have a "warp drive" or "jump drive" or something like that... at the moment 11 light years might as well be 11 million light years. it makes no difference to our ability to get there.

Exactly. Even if we DID build an Orion nuclear spacecraft (http://www.spacedaily.com/news/nuclearspace-03h.html), at best we'll get 1/10th light speed, and it would take the equivalent of several thousand Saturn V launches to build the ship in space. So we're talking at best a 220 year round trip, IF everything went right.

Re:ok, so, what now (1)

confused one (671304) | about 4 months ago | (#47787593)

Building an Orion could very well bankrupt the nation that attempts it. It would be obscenely expensive; and, while it is the best our current technology could produce, it would be a hideously inefficient way to go about travelling between stars.

Re:ok, so, what now (1)

Jason Levine (196982) | about 4 months ago | (#47785829)

Exactly. Currently, our furthest space probe is Voyager 1 and that's only 0.002 light years away from us after travelling for 37 years. At that rate, it will take 18,500 years before it travels one light year and over 200,000 years before it travels 11 light years. Even if we could leave right now and cut the travel time in half, we still wouldn't arrive until the year 102,014. To put it another way, we as a species (Homo Sapiens) have only been around for 200,000 years. A probe sent to this closest planet at Voyager's speed, would have needed to have been sent when Homo Sapiens first emerged in order for it to have arrived now.

alien planets (1)

dimeglio (456244) | about 4 months ago | (#47785605)

This is more evidence that alien planets are common in the galaxy.

Strange statement. Why would anyone think planets were uncommon in the galaxy?

Re:alien planets (3)

Jason Levine (196982) | about 4 months ago | (#47785859)

At one point, the prevailing scientific theory was that planets were a rarity. Then we found the first exoplanet and astronomers started wondering if they might be more common. By now, with the thousands of exoplanets found, we know that planets are plentiful. We don't know how many Earth-like ones are out there, but many astronomers think that this is more of a deficiency in our planetary detection methods than a rarity of Earth-like worlds. (Bigger planets are easier to detect.)

Re:alien planets (1)

Sperbels (1008585) | about 4 months ago | (#47787667)

That still doesn't explain why they would think planets were uncommon. We didn't know of any extra solar planets because we didn't have instruments that could find them...and we knew they were inadequate. Just because we were incapable of seeing them, that's no reason to believe they were uncommon. What we can infer from the known laws of physics suggests that all you need is gravity and matter and you're going to get clumps of matter orbiting other clumps matter orbiting other clumps of matter until you get stars and planets and moons and galaxies.

Re:alien planets (1)

Jason Levine (196982) | about 4 months ago | (#47797497)

You'd need to talk to an astronomer to find out the reason that astronomers at the time thought planets weren't common. It might have just been because we hadn't detected any and a lack of evidence for something translates into a certain amount of skepticism about whether that thing exists.`

Re:alien planets (1)

Anonymous Coward | about 4 months ago | (#47786535)

This is more evidence that alien planets are common in the galaxy.

Strange statement. Why would anyone think planets were uncommon in the galaxy?

I'd say that alien planets are much more common that the non-alien ones. And even the one example I know of in the latter category sometimes stretches it somewhat.

If it is too big to colonize (1)

Orion Blastar (457579) | about 4 months ago | (#47787135)

it can be used as a refueling station to reach other planet and star systems out there.

I assume since it is a Class M planet it has fossil fuels and water and other stuff we can use on it.

You can send robot shuttles to the surface to mine and collect fossil fuel and water, water can be turned into hydrogen for fuel and oxygen to breathe.

There might even be plants or soil rich enough to plant Earth plants on it, that might or might not grow in the higher gravity. Put down solar cells to collect sunlight and store energy. Move robots all over the planet to look for stuff.

Check for New Comments
Slashdot Login

Need an Account?

Forgot your password?