Talk:2079: Alpha Centauri
Possible concept projects he's referencing:
https://en.wikipedia.org/wiki/2069_Alpha_Centauri_mission or https://en.wikipedia.org/wiki/Breakthrough_Starshot
184.108.40.206 18:18, 30 November 2018 (UTC)
- Breakthrough Starshot sounds relevent enough to mention in the article. In 2016 an earth-like planet was discovered orbiting Proxima Centauri, which is the closest star in the universe to our sun. Other destinations are considered for the project, but the plan is to visit this planet. Expected velocity is 37,300 km/s. Estimated departure date is 2036, arriving by 2066. Significant funding exists. But some of the technologies do not quite yet. (for those who don't want to click the link) 220.127.116.11 21:06, 30 November 2018 (UTC)
Alpha century does have 3 stars: Alpha Centauri A (also named Rigil Kentaurus), Alpha Centauri B (also named Toliman), and a small and faint red dwarf (Class M), Alpha Centauri C (also named Proxima Centauri)
18.104.22.168 18:18, 30 November 2018 (UTC)
I don't know what the (voices off) is complaining about. We only have one star! So Alpha Centauti is an upgrade ;-) RIIW - Ponder it (talk) 18:44, 30 November 2018 (UTC)
- But if your going to upgrade, go all the way at least. (Definitely not an excuse I use to buy better PC hardware)Linker (talk) 18:49, 30 November 2018 (UTC)
Check out figure 1 on page 3 of this 2016 study: http://www.ice.csic.es/personal/iribas/Proxima_b/pdf/Proxima_habitability_II.pdf showing how likely the researchers believe there to be oceans on Proxima b. They expect us to be able to determine what's true directly in 10 years when construction of larger telescopes is completed. Most other sources I found in my brief search are very careful to say that we do not know at all whether or not there is water on this nearby exoplanet. 22.214.171.124
I (on the basis of no astrophysicists training, just being a Civil Engineer) can't help wondering that of the three planets in the Sun's Goldilocks zone* that only one has... 1. a strong enough magnetic field to prevent the solar wind stripping off a light atmosphere, that prevents the water boiling and being blown away. 2. an abnormally big moon**. 3. proven plate tectonics. 4. macro life.
And so that 2 is crucial to 1 and 3 and 3 is crucial to 4 (including 1 of course)
So why we expect liquid water everywhere is a mystery to me.
YMMV and I reserve the right to be (proved) wrong
- apparently according to various things I have read over the decades
- some believe Mars had a bigger moon (magnetic field and oceans) before it's orbit decayed and it collided.
Hmm: 4.367 light years / 35 years = 0.12477 light years/year
The above math assumes a constant speed, and requires a speed of ~0.0001c.
Wouldn't the assumed constant speed be about 12% of light-speed instead? 0.12477 light-years/year (cancel the years) = 0.12477 c.
While conventional rockets could not carry enough fuel for an accelerating trip, what about ion propulsion? Low mass ejected at really high speeds for a long time could accelerate the space craft over the entire distance, with a turn-around halfway. 0.0625 g has been achieved by modern ion thrusters. The question is whether you could still carry enough propellant for 35 years. Nutster (talk) 10:54, 2 December 2018 (UTC)
- Ion engines usually use solar panels for their energy. However, in interstellar space, there is very little light so solar panels are not very efficient. They would first have to come up with an alternative power source to circumvent that problem. 126.96.36.199 12:42, 3 December 2018 (UTC)
- I was thinking nuclear power, like what is powering all the probes to the outer planets. This would just be really out-there planets. I would need to compare the power output of, for example, Cassini's reactor to the power needs of the ion drive (as well the needs of the rest of the system during the trip) to see how well that could work. Nutster (talk) 14:06, 3 December 2018 (UTC)
Not sure if I am the only one wanting to know how long it would take now and add it to the article; Distance to Alpha Centauri system = 4.367ly / fastest current speed 39,897km/h = 1.041 billion hours = 118757 years --188.8.131.52 12:35, 4 December 2018 (UTC)
How is the rate of acceleration determined in the calculations above? Why not decrease it a bit and let it take longer time but save energy?