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The fun stuff is buried in footnote [4]: > The actual suitability of this kind of planet to support water and Earth-like life is a matter of intense but mostly
by mjhoy 10y ago
The fun stuff is buried in footnote [4]:
> The actual suitability of this kind of planet to support water and Earth-like life is a matter of intense but mostly theoretical debate. Major concerns that count against the presence of life are related to the closeness of the star. For example gravitational forces probably lock the same side of the planet in perpetual daylight, while the other side is in perpetual night. The planet's atmosphere might also slowly be evaporating or have more complex chemistry than Earth’s due to stronger ultraviolet and X-ray radiation, especially during the first billion years of the star’s life. However, none of the arguments has been proven conclusively and they are unlikely to be settled without direct observational evidence and characterisation of the planet’s atmosphere. Similar factors apply to the planets recently found around TRAPPIST-1.
- dmix 10y agoNow we can factor in "always sunny" or "always dark" to our simulations of what aliens might look like (maybe even two races/species from the same planet?).
- bshimmin 10y agoFor example gravitational forces probably lock the same side of the planet in perpetual daylight, while the other side is in perpetual night. Should I admit on HN to having watched a Vin Diesel film? Pitch Black, anyone?
- strictnein 10y agoOf course. Vin Diesel movies have their place and are fun. Pitch Black was great. Riddick is a good anti-hero.
- fernandopj 10y agoPlanet rotation is 83 days [1]. So no, no perpetual days or nights on Proxima b. [1] http://edition.cnn.com/2016/08/24/health/proxima-b-centauri-rocky-planet-habitable-zone-neighbor-star/ http://edition.cnn.com/2016/08/24/health/proxima-b-centauri-...
- vojvod 10y ago83 days is the star's rotation period.
- ncallaway 10y agoIf I remember right Pitch Black wasn't a tidally locked planet, but rather an _extended_ eclipsed caused by the other planets in their stellar system. Astronomy nerdship aside, I loved Pitch Black. Such a good movie. I haven't watched any of the sequels, though. The first game that they released, surprisingly for a movie to game adaptation, was also quite good.
- SmurfJuggler 10y agoThat's because Vin Diesel is a gamer and didn't want games starting him to be run-of-the-mill movie tie/cash-ins, so he founded Tigon and tasked them with making good ones. Fabulously geeky dude, I like his style.
- someone7x 10y agoYes, Escape From Butcher Bay. A gem of game from the first-gen xbox era. Not sure if it holds up, but at the time it was a very high quality release.
- euyyn 10y agoI loved the sequel myself.
- valarauca1 10y agoAlso Proxima Centauri is a Flare Star. So it's light output can vary by +/- 8%. And this can change within a matter of weeks. It is actually the most active flare star we know. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1063292/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1063292/
- noobermin 10y agoEven more interesting, if life does happen there, the imagination required to picture such life would be a fun exercise.
- runesoerensen 10y agoCool so it's an "eyeball" planet? http://nautil.us/blog/forget-earth_likewell-first-find-aliens-on-eyeball-planets http://nautil.us/blog/forget-earth_likewell-first-find-alien...
- rezashirazian 10y agoThis is the first time I'm reading about this concept and I find it fascinating. If there was to be intelligent life on an eye ball like planet the cultural, mythological and theological aspects of having a thin habitable strip of land sandwiched between ice and fire would be captivating.
- valarauca1 10y agoI'm imaging an age of discovery-esque expeditions to the center of the Solar Plane. They'd likely have radically different definitions of poles. One hot enough to melt lead, one cold enough to freeze C02.
- thaumasiotes 10y ago> They'd likely have radically different definitions of poles. One hot enough to melt lead, one cold enough to freeze C02. Well, in a certain sense the West Pole and East Pole would exist in the manner you describe, but the behavior is not similar to that of the north and south poles. The stars will still rotate around the north-south axis, and east-west still won't affect that. It's not obvious that both phenomena should be called "poles".
- dragonwriter 10y ago> The stars will still rotate around the north-south axis, and east-west still won't affect that. It's not obvious that both phenomena should be called "poles". Note that "north - south" poles already refers to two distinct phenomena, the axis of rotation and the axis of the magnetic field (these happen to be closely-enough aligned on Earth that the latter has historically been used as a proxy for the former, though this is by no means a universal feature of all planets.) The axis of orientation to the sun, for a tidelocked planet, seems no less plausibly described as "poles".
- tokai 10y agoLiving at the twilight zone of such a planet would be a photographers nirvana. Golden hour every hour, for the rest of your life.
- semaphoreP 10y agoThis. It important to note that there are SO many factors that we don't know that can prevent habitability (for Earth definitions of habitability). We will need detailed study of its atmosphere to really understand habitability, and even then there are many mechanisms (e.g. volcanism) that can produce false positive biosignatures. For all we know, this planet could still have a hydrogen atmosphere (i.e. more akin to a Hot Neptune). Still, this is a really exciting discovery and will prompt a lot of follow-up studies in the future to really understand the system.
- panglott 10y agoYep, but even if it is not anything close to habitable (as it likely is not), it seems like we could learn a huge amount about about the habitability of red dwarf systems in general. https://en.wikipedia.org/wiki/Habitability_of_red_dwarf_systems https://en.wikipedia.org/wiki/Habitability_of_red_dwarf_syst...
- mjhoy 10y agoIndeed. This is one of my favorite Wikipedia articles: https://en.wikipedia.org/wiki/Rare_Earth_hypothesis https://en.wikipedia.org/wiki/Rare_Earth_hypothesis
- nonbel 10y ago>"Venus mean surface temperature is 735 K (462 °C; 863 °F) making Venus the hottest planet in the Solar System. Earth had a similar early atmosphere to Venus, but lost it in the giant impact event." Ever since I saw it done in the new Universe series, a pet peeve of mine has been treating the giant impact hypothesis as some kind of established fact. Even the name on the wikipedia page includes the term "hypothesis": https://en.wikipedia.org/wiki/Giant-impact_hypothesis https://en.wikipedia.org/wiki/Giant-impact_hypothesis The hubris surrounding the presentation of that particular hypothesis to the public is really, really awful. I actually stopped watching that new Universe series mid-episode after hearing it presented as fact (this was sometime in the first few episodes, maybe the first episode) and stopped reading this wikipedia page just now.
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- douche 10y agoI'm trying to imagine what that might look like if you're on the surface of this thing looking up at the sky. The sun would be really close, comparatively, and even as a red dwarf, rather than main sequence like our sun, it must take up a huge portion of the sky. I would assume, if the planet is tidally-locked, that the sun would pretty much always be at the same point in the sky, when viewed from the same location? Fun to think about, anyway.
- cgriswald 10y agoWe don't have to think about it. We can do the math. The distance between the planet and the star is ˜7,000,000 km. The diameter of the star is roughly 1.5 * the diameter of Jupiter: 207525 km. The angular size of the star from the surface of the planet will be the arcsin of (207525 / 7*10ˆ6) or about 1.7 degrees. This is a little bigger than three times the apparent size of the full moon or the sun from Earth.
- douche 10y agoThanks!
- reitoei 10y agoIt's Always Sunny in Proxima b