# Planet at Proxima ?? **URL:** \ **Category:** Miscellaneous and Personal Stuff I Must Share\ **Created:** [August 21, 2016, 7:53pm UTC](https://boards.straightdope.com/t/planet-at-proxima/763543 "2016-08-21T19:53:11Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![dtilque](https://avatars.discourse-cdn.com/v4/letter/d/d6d6ee/32.png) [@dtilque](https://boards.straightdope.com/u/dtilque)\ **Post date:** [August 21, 2016, 7:53pm UTC](https://boards.straightdope.com/t/planet-at-proxima/763543/1 "2016-08-21T19:53:11Z")
[del]Reports[/del] Rumors have it that an [earth-sized planet](http://phys.org/news/2016-08-earth-like-planet-proxima-centauri.html) has been discovered in Proxima Centauri’s habitable zone. No official report yet, just an unofficial one in Der Spiegel. Proxima is a red dwarf and a [flare star](https://en.wikipedia.org/wiki/Flare_star), so don’t get your hopes too high for life there. Anyway the official announcement, if any, should be made by the end fo the month. ---
**Author:** ![The\_Vorlon](https://avatars.discourse-cdn.com/v4/letter/t/d07c76/32.png) [@The\_Vorlon](https://boards.straightdope.com/u/The_Vorlon)\ **Post date:** [August 23, 2016, 8:02pm UTC](https://boards.straightdope.com/t/planet-at-proxima/763543/2 "2016-08-23T20:02:51Z")
Lets see, Class M flare star, so the possible world is tide-locked? “But Keptin, this is the garden spot of Ceti Alpha 5…” ---
**Author:** ![Voyager](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/voyager/32/133_2.png) [@Voyager](https://boards.straightdope.com/u/Voyager)\ **Post date:** [August 24, 2016, 5:38pm UTC](https://boards.straightdope.com/t/planet-at-proxima/763543/3 "2016-08-24T17:38:59Z")
Just been published. [Article about it in The Register](http://www.theregister.co.uk/2016/08/24/exoplanet_found_right_under_our_noses_may_be_earthlike/). Very cool discovery. It seems habitable, in the Goldilocks zone, but no one knows if it has water, an atmosphere or life. ---
**Author:** ![cochrane](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cochrane/32/10441_2.png) [@cochrane](https://boards.straightdope.com/u/cochrane)\ **Post date:** [August 24, 2016, 5:47pm UTC](https://boards.straightdope.com/t/planet-at-proxima/763543/4 "2016-08-24T17:47:58Z")
Sounds like a good destination for Zefram Cochrane to check out in about 45 years. 🙂 ---
**Author:** ![nachtmusick](https://avatars.discourse-cdn.com/v4/letter/n/ac91a4/32.png) [@nachtmusick](https://boards.straightdope.com/u/nachtmusick)\ **Post date:** [August 26, 2016, 12:31am UTC](https://boards.straightdope.com/t/planet-at-proxima/763543/5 "2016-08-26T00:31:46Z")
> [@The\_Vorlon](#): > > Lets see, Class M flare star, so the possible world is tide-locked? > > “But Keptin, this is the garden spot of Ceti Alpha 5…” The news outlets are being a little irresponsible about this. Most just say “potentially habitable”. I finally found an article that admitted it was probably tide-locked. So extreme temperatures, extreme radiation, and the flares would have stripped the atmosphere away long ago (like Mars). But hey, it’s in the Goldilocks Zone! ---
**Author:** ![levdrakon](https://avatars.discourse-cdn.com/v4/letter/l/49beb7/32.png) [@levdrakon](https://boards.straightdope.com/u/levdrakon)\ **Post date:** [September 6, 2016, 6:15pm UTC](https://boards.straightdope.com/t/planet-at-proxima/763543/6 "2016-09-06T18:15:14Z")
Habitable in astronomy just means it could have liquid water on its surface. Nothing wrong with calling it habitable. Being tidally locked around a temperamental red dwarf used to be thought to be a deal breaker for life, but lately there is more debate about that. A thick atmosphere might spread heat around, for instance. What’s interesting to me isn’t so much whether or not it has life, but how common earth-like planets in habitable zones are. We found one around the nearest star. What are the odds of that? Perhaps earth-like planets in habitable zones are much more common than we supposed. ---
**Author:** ![Duke\_of\_Rat](https://avatars.discourse-cdn.com/v4/letter/d/ad7895/32.png) [@Duke\_of\_Rat](https://boards.straightdope.com/u/Duke_of_Rat)\ **Post date:** [September 6, 2016, 6:30pm UTC](https://boards.straightdope.com/t/planet-at-proxima/763543/7 "2016-09-06T18:30:08Z")
I think the public gets caught out with the “only 20 years away!” part, not realizing that .2C is a LOT faster than anything we currently have. I think it would take a craft the speed of New Horizons (fastest thing ever launched from Earth, but maybe a Voyager is faster after some gravity assist moves) about 50,000 years to make the trip - for a flyby. Stopping once there is another kettle of fish. I’ve read about the laser powered nano-bot craft, that’s where the .2C comes from I think. Keeping a laser trained on something that small for long enough to get to .2C seems like a challenge in itself, but I absolutely support them having a go at it. If they launched today, I wouldn’t live to see the return signal, so that’s a bummer. ---
**Author:** ![carnivorousplant](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/carnivorousplant/32/3563_2.png) [@carnivorousplant](https://boards.straightdope.com/u/carnivorousplant)\ **Post date:** [September 6, 2016, 7:21pm UTC](https://boards.straightdope.com/t/planet-at-proxima/763543/8 "2016-09-06T19:21:06Z")
> [@Duke\_of\_Rat](#): > > Keeping a laser trained on something that small for long enough to get to .2C seems like a challenge in itself, but I absolutely support them having a go at it. Process control would be a bitch. ---
**Author:** ![kanicbird](https://avatars.discourse-cdn.com/v4/letter/k/5f8ce5/32.png) [@kanicbird](https://boards.straightdope.com/u/kanicbird)\ **Post date:** [September 6, 2016, 8:27pm UTC](https://boards.straightdope.com/t/planet-at-proxima/763543/9 "2016-09-06T20:27:57Z")
> [@Duke\_of\_Rat](#): > > I think the public gets caught out with the “only 20 years away!” part, not realizing that .2C is a LOT faster than anything we currently have. I think it would take a craft the speed of New Horizons (fastest thing ever launched from Earth, but maybe a Voyager is faster after some gravity assist moves) about 50,000 years to make the trip - for a flyby. Stopping once there is another kettle of fish. I’ve read about the laser powered nano-bot craft, that’s where the .2C comes from I think. Keeping a laser trained on something that small for long enough to get to .2C seems like a challenge in itself, but I absolutely support them having a go at it. If they launched today, I wouldn’t live to see the return signal, so that’s a bummer. Could we transmit a signal back from there and still be able to receive it from such a small craft? ---
**Author:** ![dtilque](https://avatars.discourse-cdn.com/v4/letter/d/d6d6ee/32.png) [@dtilque](https://boards.straightdope.com/u/dtilque)\ **Post date:** [September 6, 2016, 8:51pm UTC](https://boards.straightdope.com/t/planet-at-proxima/763543/10 "2016-09-06T20:51:03Z")
> [@levdrakon](#): > > Being tidally locked around a temperamental red dwarf used to be thought to be a deal breaker for life, but lately there is more debate about that. A thick atmosphere might spread heat around, for instance. This paper: [Asynchronous rotation of Earth-mass planets in the habitable zone of lower-mass stars](http://www.google.com/url?q=https://arxiv.org/pdf/1502.01952&sa=U&ved=0ahUKEwjH4qOKzPvOAhWH5YMKHbohCToQFggbMAM&usg=AFQjCNHGVPp_MF-SFQ0a6wMfZzwDRchQjQ) (pdf) says that planets with atmospheres that would ordinarily tidal lock, should actually have some rotation, just like Venus. > [@Leconte](#): > > Planets in the habitable zone of lower-mass stars are often assumed to be in a > state of tidally synchronized rotation, which would considerably affect their pu- > tative habitability. Although thermal tides cause Venus to rotate retrogradely, > simple scaling arguments tend to attribute this peculiarity to the massive Venu- > sian atmosphere. Using a global climate model, we show that even a relatively > thin atmosphere can drive terrestrial planets’ rotation away from synchronic- > ity. We derive a more realistic atmospheric tide model that predicts four asyn- > chronous equilibrium spin states, two being stable, when the amplitude of the > thermal tide exceeds a threshold that is met for habitable Earth-like planets > with a 1 bar atmosphere around stars more massive than ∼ 0.5 − 0.7 M[sub]Sun[/sub]. Thus, > many recently discovered terrestrial planets could exhibit asynchronous spin- > orbit rotation, even with a thin atmosphere. ---
**Author:** ![levdrakon](https://avatars.discourse-cdn.com/v4/letter/l/49beb7/32.png) [@levdrakon](https://boards.straightdope.com/u/levdrakon)\ **Post date:** [September 6, 2016, 9:19pm UTC](https://boards.straightdope.com/t/planet-at-proxima/763543/11 "2016-09-06T21:19:21Z")
Time to update the Drake Equation. ---
**Author:** ![wolfpup](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/wolfpup/32/10618_2.png) [@wolfpup](https://boards.straightdope.com/u/wolfpup)\ **Post date:** [September 6, 2016, 9:31pm UTC](https://boards.straightdope.com/t/planet-at-proxima/763543/12 "2016-09-06T21:31:27Z")
> [@levdrakon](#): > > Time to update the Drake Equation. Yep. When it’s planets everywhere we look, and the better we can detect them, the more there are, that should tell us something! ---
**Author:** ![Ann\_Hedonia](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ann_hedonia/32/319_2.png) [@Ann\_Hedonia](https://boards.straightdope.com/u/Ann_Hedonia)\ **Post date:** [September 7, 2016, 12:08am UTC](https://boards.straightdope.com/t/planet-at-proxima/763543/13 "2016-09-07T00:08:00Z")
Steven Baxter wrote a novel about this very subject. Proxima is about the colonization of a tidally locked planet is close orbit to Proxima. > **[Goodreads](https://www.goodreads.com/book/show/17983396-proxima?ac=1&from_search=true)** > > Discover and share books you love on Goodreads. I enjoyed the book and its sequel, Ultima (which is more metaphysical and not so much about world-building.) ---
**Author:** ![carnivorousplant](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/carnivorousplant/32/3563_2.png) [@carnivorousplant](https://boards.straightdope.com/u/carnivorousplant)\ **Post date:** [September 7, 2016, 12:09am UTC](https://boards.straightdope.com/t/planet-at-proxima/763543/14 "2016-09-07T00:09:55Z")
> [@kanicbird](#): > > Could we transmit a signal back from there and still be able to receive it from such a small craft? I believe that is dependent upon the size of the antenna and the power of the transmitter, but upon reflection, that is related to size. Upon further reflection, I vaguely recall that the plan is to have several small craft relaying transmissions. ---
**Author:** ![dtilque](https://avatars.discourse-cdn.com/v4/letter/d/d6d6ee/32.png) [@dtilque](https://boards.straightdope.com/u/dtilque)\ **Post date:** [September 7, 2016, 12:26am UTC](https://boards.straightdope.com/t/planet-at-proxima/763543/15 "2016-09-07T00:26:19Z")
> [@wolfpup](#): > > Yep. When it’s planets everywhere we look, and the better we can detect them, the more there are, that should tell us something! Well, we haven’t found planets everywhere. In fact, most stars, even a restricted subset of them such as very nearby stars, have not had planets detected near them. But that’s a function of our detection modes, which preferentially detect large planets near the stars. So yes, we may have to update that equation, but we need more data first. As far as inhabitability, the formula doesn’t have much in it about the physical details of the planets. That’s probably intentional, but as we get more data, we may want to incorporate them. Everyone looks at the size of the planets, but how about the density of the atmospheres? I expect that few planets will actually have near-Earth atmospheric density. More likely they’ll have little or none (Mercury and Mars) or very high density (Venus). ---
**Author:** ![carnivorousplant](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/carnivorousplant/32/3563_2.png) [@carnivorousplant](https://boards.straightdope.com/u/carnivorousplant)\ **Post date:** [September 7, 2016, 12:46am UTC](https://boards.straightdope.com/t/planet-at-proxima/763543/16 "2016-09-07T00:46:09Z")
I wonder if other planets have seen Jupiter and have sent similar probes. ---
**Author:** ![levdrakon](https://avatars.discourse-cdn.com/v4/letter/l/49beb7/32.png) [@levdrakon](https://boards.straightdope.com/u/levdrakon)\ **Post date:** [September 7, 2016, 12:49am UTC](https://boards.straightdope.com/t/planet-at-proxima/763543/17 "2016-09-07T00:49:24Z")
> [@carnivorousplant](#): > > I wonder if other planets have seen Jupiter and have sent similar probes. They probably thought, “oh another gas giant. No life.” ---
**Author:** ![kanicbird](https://avatars.discourse-cdn.com/v4/letter/k/5f8ce5/32.png) [@kanicbird](https://boards.straightdope.com/u/kanicbird)\ **Post date:** [September 7, 2016, 12:51am UTC](https://boards.straightdope.com/t/planet-at-proxima/763543/18 "2016-09-07T00:51:57Z")
> [@dtilque](#): > > As far as inhabitability, the formula doesn’t have much in it about the physical details of the planets. . And totally ignores moons. ---
**Author:** ![carnivorousplant](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/carnivorousplant/32/3563_2.png) [@carnivorousplant](https://boards.straightdope.com/u/carnivorousplant)\ **Post date:** [September 7, 2016, 12:53am UTC](https://boards.straightdope.com/t/planet-at-proxima/763543/19 "2016-09-07T00:53:14Z")
> [@levdrakon](#): > > They probably thought, “oh another gas giant. No life.” Yes, but our astronomers are speculating that a solar system with gas giants might have habitable worlds. ---
**Author:** ![levdrakon](https://avatars.discourse-cdn.com/v4/letter/l/49beb7/32.png) [@levdrakon](https://boards.straightdope.com/u/levdrakon)\ **Post date:** [September 7, 2016, 1:01am UTC](https://boards.straightdope.com/t/planet-at-proxima/763543/20 "2016-09-07T01:01:55Z")
> [@carnivorousplant](#): > > Yes, but our astronomers are speculating that a solar system with gas giants might have habitable worlds. So you’re wondering if alien astronomers have looked at our system and wondered? We’ve had chlorophyll pumping out way more O2 than we should have for like 3 billion years or more, so I hope they realize something weird is going on here. Why their probes aren’t dropping out of the sky is another question. 🙂 [Next page](https://boards.straightdope.com/t/planet-at-proxima/763543.md?page=2)