How Can We Reach Habitable Exoplanets?

[cjackson]

According to Wikipedia, there could be as many as 11 billion planets in the habitable zone of sun-like stars, with the closest potentially 12 light years away. That number goes up to 40 billion if you include red dwarfs. How would we even go about getting to the nearest Exoearth?

 

[Doug Huffman]

It's not possible with current or foreseeable technology or physics.

 

[Chronos]

We are still trying to figure out how to safely send humans to mars, which is obscenely close compared to the nearest star. The fuel requirements alone are vast beyond imagination. Realistically, it appears interstellar travel is centuries beyond our grasp. For discussion, see http://arxiv.org/abs/1101.1066.

 

[Doug Huffman]

Robert L. Forward is cited in your
Energy, incessant obsolescence, and the first interstellar missions

 

[phinds]

According to Wikipedia, there could be as many as 11 billion planets in the habitable zone of sun-like stars, with the closest potentially 12 light years away. That number goes up to 40 billion if you include red dwarfs. How would we even go about getting to the nearest Exoearth?

In addition to the other responses, be aware that your statement is not, technically, correct. Science depends on precise terminology and you have described a limited range without specifying it. That is, you have implied that "11 billion planets" encompasses the entire universe but it does not, it is the subset in the observable universe, not "the universe". Just because Wikipedia gets it wrong (and I'm assuming they did not say observable universe) does not make it right. The number of planets in the universe could be infinite in which case the number of inhabitable planets is also infinite and that's WAY bigger than 11 billion

 

[mfb]

We are still trying to figure out how to safely send humans to mars, which is obscenely close compared to the nearest star. The fuel requirements alone are vast beyond imagination. Realistically, it appears interstellar travel is centuries beyond our grasp. For discussion, see http://arxiv.org/abs/1101.1066.

Our knowledge is increasing more rapidly than ever before. I would not make predictions for centuries in the future. The past is full of wrong "impossible"-predictions about technology. Sure, you can take the last decades and extrapolate into the future - I wonder which number of computers or spaceflights for today such a prediction would have given 1915.

@phinds: that number refers to our galaxy.

 

[phinds]

Our knowledge is increasing more rapidly than ever before. I would not make predictions for centuries in the future. The past is full of wrong "impossible"-predictions about technology. Sure, you can take the last decades and extrapolate into the future - I wonder which number of computers or spaceflights for today such a prediction would have given 1915.

I agree w/ you, but the speed of light limit doesn't seem like something that is going to go away.

@phinds: that number refers to our galaxy.

Ha. An even smaller limit that should have been specified.

 

[mfb]

I'm not talking about superluminal travel - 10% the speed of light allow to travel 10 light years in 100 years.

 

[phinds]

I'm not talking about superluminal travel - 10% the speed of light allow to travel 10 light years in 100 years.

Sorry, I should have been more clear. I didn't for a minute think you were talking about FTL. At 10% of c, I still think there are very significant shielding problems and others as well. I do agree that these are primarily just engineering problems and who knows what we might have to address them with in 50 years or 100 years and more.