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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

#111

Post by spullara »

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...

I couldn't find anything with its approximate radius (it mentions about-earth sized and 8x the mass but that could mean anything) to make an evaluation of the likely gravitational force at the surface in order to make the evaluation of whether you could get off the planet cheaply.

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

#112

Post by [deleted] »

vecter wrote: post #104
typeformer wrote: post #94

Earlier quoted context omitted.

The government has been studying UFO's at the highest levels since at least 1947 and likely prior. You don't study something closely for 7 decades and not learn anything. https://www.cia.gov/library/center-for-the-study-of-intellig...

UFOs are literally just Unidentified Flying Objects. Doesn't mean that they're alien in origin (and in fact, they're almost certainly not).

[deleted]

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

#113

Post by brlewis »

typeformer wrote: post #94
fooker wrote: post #74

Earlier quoted context omitted.

Evidence?

The government has been studying UFO's at the highest levels since at least 1947 and likely prior. You don't study something closely for 7 decades and not learn anything. https://www.cia.gov/library/center-for-the-study-of-intellig...

OK let me see if I understand the chain of inference here.

  The government has been studying UFOs for 7 decades
  ==> The government has learned something
  ==> The government has acquired alien technology
I'm mostly with you on that first arrow, but you lost me on the 2nd.

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

#114

Post by sandworm101 »

dogma1138 wrote: post #105
soulofmischief wrote: post #38

Earlier quoted context omitted.

So... if one made a very aerodynamic craft, and launched at a more extreme lateral angle, do you think it would supplement the chemical rockets enough that escape would be possible?

not really going to orbit is about velocity not altitude the gravity at low earth orbit is pretty much the same as at sea level. The savings you get when launching from say an aircraft at 40,000 feet mainly come from not having to go through max-q at sea level the relative amount of propellant you’ll need to get to orbit is the same you can just use a smaller rocket but it doesn’t help to overcome the rocket equation…

But at altitude you do get higher ISP, which is a greater limiting factor than drag/max-Q. The Saturn-V would not even get off the pad in an even slightly denser atmosphere. But lift it up to where the air is thinner, where its engines can generate more thrust, and it might have enough DeltaV to get something into an orbit.

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

#115

Post by chenning »

A very quick search suggests that earth will become uninhabitable somewhere between 500 million and 2 billion years from now. If we shot a probe to this life-friendly alien planet with some sort of primordial soup, even traveling at the speed of light it would take 4 billion earth years to get there. Do I have that right? Basically we'll never even come close to being around when it finally arrives, if it ever arrives. Has anyone ever thought about doing this? We've shot gold records out into space for aliens with turn-tables. Why haven't we tried this?

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

#116

Post by 0xffff2 »

AgentME wrote: post #33
Miner49er wrote: post #11

Earlier quoted context omitted.

Solar sails might be able to beat it. https://en.wikipedia.org/wiki/Solar_sail

Aren't solar sails just for propelling yourself once you're in space? I can't imagine how you could launch off the surface of a planet with a solar sail.

Yes, and even then they're incredibly low thrust devices. A light sail (whether solar or laser powered) may well be viable for sending a tiny unmanned probe to another star system (see [0]). It's really unlikely that it will ever scale up enough to take an average communication satellite the same distance, much less a manned craft.

[0] https://en.wikipedia.org/wiki/Breakthrough_Starshot

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

#117

Post by perseusprime11 »

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.

At 111 light-years, we need to create a vehicle that can sustain several generations.

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

#118

Post by rossdavidh »

typeformer wrote: post #94
fooker wrote: post #74

Earlier quoted context omitted.

Evidence?

The government has been studying UFO's at the highest levels since at least 1947 and likely prior. You don't study something closely for 7 decades and not learn anything. https://www.cia.gov/library/center-for-the-study-of-intellig...

"You don't study something closely for 7 decades and not learn anything..."

I do believe that any qualified historian of science could point out to you topics in linguistics (origin of language), psychology (nature of consciousness), astrophysics (what's inside a black hole, if anything), and many other topics where more than 7 decades have gone by, with lots of smart people studying a topic, and yet at the end of that much time practically nothing has been learned.

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

#119

Post by 0xffff2 »

chenning wrote: post #115

A very quick search suggests that earth will become uninhabitable somewhere between 500 million and 2 billion years from now. If we shot a probe to this life-friendly alien planet with some sort of primordial soup, even traveling at the speed of light it would take 4 billion earth years to get there. Do I have that right? Basically we'll never even come close to being around when it finally arrives, if it ever arrive…

>A very quick search suggests that earth will become inhabitable somewhere between 500 million and 2 billion years from now.

I'm 99% sure that Earth is inhabitable right now... perhaps you meant "uninhabitable"?

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

#120

Post by chenning »

0xffff2 wrote: post #119
chenning wrote: post #115

A very quick search suggests that earth will become uninhabitable somewhere between 500 million and 2 billion years from now. If we shot a probe to this life-friendly alien planet with some sort of primordial soup, even traveling at the speed of light it would take 4 billion earth years to get there. Do I have that right? Basically we'll never even come close to being around when it finally arrives, if it ever arrive…

>A very quick search suggests that earth will become inhabitable somewhere between 500 million and 2 billion years from now. I'm 99% sure that Earth is inhabitable right now ... perhaps you meant "uninhabitable"?

Is it though??? (edited, thanks)
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