←back to thread

The Universe Within 12.5 Light Years

(www.atlasoftheuniverse.com)
266 points algorithmista | 4 comments | 05 Sep 25 22:20 UTC | HN request time: 0s | source
Show context
ghssds ◴[05 Sep 25 23:54 UTC] No.45145093[source]▶
It should be a goal for Earth to send a probe to one of those stars. As the probe will be unmaned, a mission taking a hundred years or more is not out of question.
replies(5): >>45145118 #>>45145325 #>>45145386 #>>45145822 #>>45146134 #
pkaye ◴[05 Sep 25 23:56 UTC] No.45145118[source]▶
How would it be powered?
replies(1): >>45145197 #
mattnewton ◴[06 Sep 25 00:09 UTC] No.45145197[source]▶
some combination of nuclear radiation and/or solar seems like it would fit the bill? 100 years is within the useful range of a large radioisotope generator.

https://en.m.wikipedia.org/wiki/Radioisotope_thermoelectric_...

replies(2): >>45145394 #>>45145586 #
lazide ◴[06 Sep 25 00:35 UTC] No.45145394[source]▶
RTGs lose power rapidly as the isotopes decay, and any sort of communication over those distances requires massive power. The Voyagers are essentially dead due to this issue, and they haven’t been out there nearly that long.
replies(2): >>45145593 #>>45145947 #
no_wizard ◴[06 Sep 25 01:04 UTC] No.45145593[source]▶
What about a fission reactor?
replies(2): >>45145685 #>>45146175 #
1. ekianjo ◴[06 Sep 25 01:20 UTC] No.45145685{3}[source]▶
That runs for dozens of years without maintenance? And how do you dissipate the heat?
replies(1): >>45147058 #
2. yread ◴[06 Sep 25 06:20 UTC] No.45147058[source]▶
Open the rear end and you get propulsion as well. Just don't start close to earth
replies(1): >>45151668 #
3. sfink ◴[06 Sep 25 18:26 UTC] No.45151668[source]▶
You still need matter to carry the heat, and matter is heavy (by definition!) Radiating the heat isn't going to be enough if you want to send anything other than a blob of plasma.

Which is an interesting thought when considered as a weapon. Fire a self-immolating fission reactor at your target...

replies(1): >>45152126 #
4. lazide ◴[06 Sep 25 19:22 UTC] No.45152126{3}[source]▶
I miss the days when a Bussard Ramjet was a viable dream.

Also, if there are aliens there, sending a highly radioactive blob of plasma at them at interstellar speeds might cause a little trouble.