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Water found on a potentially life-friendly alien planet

nationalgeographic.com

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Re: Water found on a potentially life-friendly alien planet

#11

Post by Miner49er »

kadoban wrote: post #8
transreal wrote: post #2

With a planet this large, visiting it would be a one way trip due to the "The Tyranny of the Rocket Equation" [0]. I'm looking forward to the day we start finding exo-planets that are closer to Earth in size and which could potentially have space-faring races (and which we could leave if we were ever to visit them). [0] - https://www.nasa.gov/mission_pages/station/expeditions/exped...

So that's purely for a chemical rocket, right? Is there any combination of tricks that can realistically push the envelope there? For example can we use a space elevator to start higher/faster (or, I don't know, balloons? a catapult or railgun or something?), laser power delivery from the ground, so we don't have to carry all the fuel, and an orbiting way-station for refueling, etc.?

Solar sails might be able to beat it.

https://en.wikipedia.org/wiki/Solar_sail

Re: Water found on a potentially life-friendly alien planet

#12

Post by Miner49er »

tyri_kai_psomi wrote: post #10
Miner49er wrote: post #6

It's depressing to think that if there is intelligent life on that planet, we won't be able to communicate with them in any way in our lifetime, yet it's so close. Unless they started sending communications our way over a century ago.

If it is depressing to think about it, then why think about it? Does it have any real implications for significant outcomes about your life or is it in a way some type of FOMO?

Well, I suppose I'm using a bit of hyperbole. Maybe I should say sad. And don't worry, I won't think about it very long.

Re: Water found on a potentially life-friendly alien planet

#14

Post by allannienhuis »

JumpCrisscross wrote: post #3
transreal wrote: post #2

With a planet this large, visiting it would be a one way trip due to the "The Tyranny of the Rocket Equation" [0]. I'm looking forward to the day we start finding exo-planets that are closer to Earth in size and which could potentially have space-faring races (and which we could leave if we were ever to visit them). [0] - https://www.nasa.gov/mission_pages/station/expeditions/exped...

> With a planet this large, visiting it would be a one way trip Assuming chemical propulsion and no refuelling at the destination.

The amount of fuel at the destination doesn't change the rocket equation for being able to get into orbit from the planet. From the provided link:

"If the radius of our planet were larger, there could be a point at which an Earth escaping rocket could not be built. That radius would be about 9680 kilometers (Earth is 6670 km). If our planet was 50% larger in diameter, we would not be able to venture into space, at least using rockets for transport."

Re: Water found on a potentially life-friendly alien planet

#16

Post by sandworm101 »

dogma1138 wrote: post #7
JumpCrisscross wrote: post #3

Earlier quoted context omitted.

> With a planet this large, visiting it would be a one way trip Assuming chemical propulsion and no refuelling at the destination.

I think what the GP refers to is that there isn’t enough energy in chemical rockets to overcome its gravity, even flight might not be even possible albeit that’s also dependent on the density of the atmosphere to some extent.

Flight would actually be easier on such a planet. The advantage of increased atmospheric density is greater than the downside of the increased gravity.

Re: Water found on a potentially life-friendly alien planet

#17

Post by SJSque »

transreal wrote: post #2

With a planet this large, visiting it would be a one way trip due to the "The Tyranny of the Rocket Equation" [0]. I'm looking forward to the day we start finding exo-planets that are closer to Earth in size and which could potentially have space-faring races (and which we could leave if we were ever to visit them). [0] - https://www.nasa.gov/mission_pages/station/expeditions/exped...

There's also the Wait Calculation to consider:

https://en.wikipedia.org/wiki/Interstellar_travel#Wait_calcu...

Re: Water found on a potentially life-friendly alien planet

#18

Post by ajconway »

archgoon wrote: post #4
transreal wrote: post #2

With a planet this large, visiting it would be a one way trip due to the "The Tyranny of the Rocket Equation" [0]. I'm looking forward to the day we start finding exo-planets that are closer to Earth in size and which could potentially have space-faring races (and which we could leave if we were ever to visit them). [0] - https://www.nasa.gov/mission_pages/station/expeditions/exped...

It's 111 light years away. For all intents and purposes, that's a one way trip right there; irregardless of the rocket equation. Even at relativistic speeds, you can't come home anymore.

Theoretically, you can. At 0.99c 111 light years take about 15 years of ship time to travel.

Re: Water found on a potentially life-friendly alien planet

#19

Post by gist »

Miner49er wrote: post #12
tyri_kai_psomi wrote: post #10

Earlier quoted context omitted.

If it is depressing to think about it, then why think about it? Does it have any real implications for significant outcomes about your life or is it in a way some type of FOMO?

Well, I suppose I'm using a bit of hyperbole. Maybe I should say sad. And don't worry, I won't think about it very long.

Why is it sad at all? What would it do for you? It would be about as relevant as being able to communicate in some way with people in the past. Would be interesting and entertaining but a leap to imagine it would yield some kind of better quality of life in the current day.

Re: Water found on a potentially life-friendly alien planet

#20

Post by archgoon »

ajconway wrote: post #18
archgoon wrote: post #4

Earlier quoted context omitted.

It's 111 light years away. For all intents and purposes, that's a one way trip right there; irregardless of the rocket equation. Even at relativistic speeds, you can't come home anymore.

Theoretically, you can. At 0.99c 111 light years take about 15 years of ship time to travel.

You can make the trip arbitrarily small from your perspective (in theory at least :) ). The issue is that by the time you've made it back home, it's 222 years later. Hence "you can't go home anymore". :)
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