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Four Earth-sized planets detected orbiting the nearest sun-like star

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Re: Four Earth-sized planets detected orbiting the nearest sun-like star

#31
post #18

Earlier quoted context omitted.

If we wanted it badly enough, we could get to tau Ceti with current technology. The Orion designs are sound, and could carry a population capable of sustaining itself for the 100-odd years it would take to get there.

Orion designs really only work if you're evacuating the planet. Massive fallout and radiation would be caused by each launch.

Orion isn't a launch drive, it's a transit drive.

Re: Four Earth-sized planets detected orbiting the nearest sun-like star

#32
post #15
post #12

Earlier quoted context omitted.

Can you say they _don't_ transit? They say the planets were detected by analyzing star wobbles, which doesn't necessarily mean that the planets don't transit, just that it's not how they were detected.

Well it doesn't transit from our point of view, so yes, I think he can say that as the observer. "In astronomy, a transit or astronomical transit is the phenomenon of at least one celestial body appearing to move across the face of another celestial body, hiding a small part of it, as seen by an observer at some particular vantage point."[0] [0] https://en.wikipedia.org/wiki/Transit_(astronomy)

I understand that. I guess I don't know how small we can reliably view transits. We can certainly see large planet transits. Perhaps planets of this size are too small to view at this distance/ with this star type with our current technology. Just because we haven't observed a transit doesn't mean the transit isn't happening. But again, I don't really know this specific circumstance.

Re: Four Earth-sized planets detected orbiting the nearest sun-like star

#33
post #2

Hearing distances like 12 light years makes you think if it is ever possible to travel there. However, when you start to think about it, nihilist thoughts start to kick in.

12 light years is actually very close as interstellar distances go. Such a mission could probably be launched in our lifetimes if the whole world got together behind it (which they won't but still...)

Re: Four Earth-sized planets detected orbiting the nearest sun-like star

#34

Earlier quoted context omitted.

Orion designs really only work if you're evacuating the planet. Massive fallout and radiation would be caused by each launch.

Orion isn't a launch drive, it's a transit drive.

"Early versions of this vehicle were proposed to take off from the ground with significant associated nuclear fallout; later versions were presented for use only in space."

Re: Four Earth-sized planets detected orbiting the nearest sun-like star

#35
post #6

Key line to mitigate disappointment: "The outer two planets around tau Ceti are likely to be candidate habitable worlds, although a massive debris disc around the star probably reduces their habitability due to intensive bombardment by asteroids and comets."

We'll just wear helmets!

[deleted]

Re: Four Earth-sized planets detected orbiting the nearest sun-like star

#36
post #18

Earlier quoted context omitted.

If we wanted it badly enough, we could get to tau Ceti with current technology. The Orion designs are sound, and could carry a population capable of sustaining itself for the 100-odd years it would take to get there.

https://en.wikipedia.org/wiki/Project_Orion_(nuclear_propuls... Project Orion is awesome and I am a big supporter. Unfortunately people won't stand for the thousand some odd nuclear bombs it would take to get the interplanetary version out of the atmosphere. Because it is so massive, building it in space also poses a problem unless we capture a iron meteorite and bring it back or mine/build it on the moon. Both of wh…

Is there a significant difference between a nuclear explosion in space compared to on earth? Would it be less powerful or offer greater thrust?

Re: Four Earth-sized planets detected orbiting the nearest sun-like star

#37
Ok, let's assume we find a warm, watery planet like Earth's within ~20 light years, and we figure out a way to travel >= 50% the speed of light, making it somewhat reasonable to get there. If the planet's gravity is greater than 10% different from Earth's, or its Day/Night cycle is much different from Earth's, wouldn't it still be a nightmare to live on.

Anatomically modern humans have lived on Earth for 200,000 years, and the creatures we descended from have lived on Earth for 541 million years. Stuff as dumb as the moon cycles affect us. How are we going to live somewhere that isn't exactly Earth?

Re: Four Earth-sized planets detected orbiting the nearest sun-like star

#39
post #18

Earlier quoted context omitted.

If we wanted it badly enough, we could get to tau Ceti with current technology. The Orion designs are sound, and could carry a population capable of sustaining itself for the 100-odd years it would take to get there.

https://en.wikipedia.org/wiki/Project_Orion_(nuclear_propuls... Project Orion is awesome and I am a big supporter. Unfortunately people won't stand for the thousand some odd nuclear bombs it would take to get the interplanetary version out of the atmosphere. Because it is so massive, building it in space also poses a problem unless we capture a iron meteorite and bring it back or mine/build it on the moon. Both of wh…

[deleted]

Re: Four Earth-sized planets detected orbiting the nearest sun-like star

#40

Ok, let's assume we find a warm, watery planet like Earth's within ~20 light years, and we figure out a way to travel >= 50% the speed of light, making it somewhat reasonable to get there. If the planet's gravity is greater than 10% different from Earth's, or its Day/Night cycle is much different from Earth's, wouldn't it still be a nightmare to live on. Anatomically modern humans have lived on Earth for 200,000 year…

We could try with a much more doable planet like Mars. We could find out if long term survival is impossible, very difficult, possible but difficult, or doable with the right technologies. It's shocking how little appetite there is for redirecting 50% of the budget which is currently allocated to the military to space exploration.

I understand that the military is partly a large welfare program which doesn't compete with private enterprise due to different technologies and classified material, but I wish there was a movement to invest more of that time, money, and energy on basic research, climate change, energy technologies and space exploration. It's a hard sell though because I suspect that these technologies would compete heavily with established businesses.

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