CrimsonEnigma t1_je8ucn8 wrote

No. It needs to be about 8,000 light years away (or less) to start affecting the atmosphere. It would be that damage that would increase cancer risk.

Think if the ozone layer hole kept expanding globally, instead of shrinking like it’s doing now.


CrimsonEnigma t1_je5lxrb wrote

Er…no, not really.

This was about 1.9 billion light years from Earth. The closest GRB ever observed was about 130 million light years from Earth. For a GRB to pose any sort of threat to life on Earth, it would need to be about 8,000 light years from Earth, and even at that range, we wouldn’t “all be dead” (though there’d be a significant increase in things like cancer rates for the next decade or two due to atmospheric damage).


CrimsonEnigma t1_jbrt9gk wrote

The PNAC first advocated for the Space Force in "Rebuilding America’s Defenses", a September 2000 document. But talk of spinning off the Air Force Space Command into its own branch, including the name "Space Force", dates back to the 1990s.

Also, although this is kind of beside the point, PNAC didn't become the Tea Party. PNAC went defunct in 2006. Its remnants would go on to form the Foreign Policy Initiative (FPI) in 2009. The Tea Party rose to prominence in 2009, but not out of PNAC or FPI; if anything, it came out of Ron Paul's ill-fated 2008 Presidential Run. The Tea Party movement and FPI were at odds with each other early-on, with Tea Party leaders accusing FPI of trying to "co-opt their movement" (the dispute largely arose over whether or not military spending should be lowered or raised).


CrimsonEnigma t1_j8pksup wrote

> Science isn't some Matlock-esque stage play where the hero rushes up, presents incontrovertible evidence, everyone says "yeah, that explains it" and then that's the end.

In fairness, that does happen, but it's very rare. When the sensitivity conjecture was proven in computer science, the proof was short enough to be tweeted out (a formal paper a couple pages long was published at the same time).


CrimsonEnigma t1_j54y447 wrote

I believe it was Don Lind, who was selected in April 1966. He was backup for some Skylab missions, but didn’t actually fly until STS-51-B in April 1985, 19 years later.

We *might* also count Joe Engle. He was also a part of the April 1966 group, but had his first flight on STS-2 in November 1981, so only 14 1/2 years after selection. However, that’s only his NASA selection - he was also selected by the Air Force in the third Aerospace Research Pilot School class in 1961, which would put his gap at around 20 years, if we’re including USAF programs in addition to civilian ones. However again, he flew as part of the X-15 program, and some of his flights crossed the USAF’s definition of the boundary of space (50 miles), but fell short of the FAI’s mark (100 km). If we count those flights, then his first spaceflight was X-15 Flight 138, which was in June 1965 - just a few years after his USAF selection.


CrimsonEnigma t1_j2c9imt wrote

Yea, Proxima Centauri is the red dwarf. I'm not sure about Alpha Centauri B's color. Star color is weird in and of itself; while we call stars like Alpha Centauri A and the Sun "yellow dwarfs", they're actually both white - the Sun only looks yellow because the atmosphere scatters more light in the blue end of the spectrum than the red end. Were you standing on the moon and staring at the Sun, it wouldn't appear yellow at all, though staring at the Sun usually isn't a good idea.

Incidentally, Proxima Centauri has an earth-sized planet around it that's on the inner edge of the habitable zone, though probably isn't actually habitable for the reasons OP pointed out.

There is a very tentative candidate for Alpha Centauri A. If confirmed, it would be a Neptune-sized planet also in the habitable zone (though barely), though again I must emphasize that this is *extremely* tentative. These candidates pop up around stars from time to time and a lot of them turn out to just be artifacts in the data.

If it is real, though, it should be big enough, far enough away from Alpha Centauri A, and close enough to our own solar system that we might be able to observe it with the JWST.

That's a long time off, though.


CrimsonEnigma t1_iwlhbom wrote

IIRC, the bottleneck is on the capsule, not the rocket.

They’re reusing quite a bit from the Artemis 1 Orion capsule (including the avionics), so they have to complete this mission (including any evaluation after it lands) before they can take it out and finish the Orion for Artemis 2.