Stories
Slash Boxes
Comments

SoylentNews is people

posted by martyb on Thursday August 25 2016, @04:54PM   Printer-friendly
from the book-your-tickets-now dept.

Last week, news of the discovery of a potentially habitable "Earth-like" exoplanet orbiting the nearest star to our Sun (Proxima Centauri) leaked to Der Spiegel. Today, the European Southern Observatory confirmed the news about Proxima b:

Astronomers using ESO telescopes and other facilities have found clear evidence of a planet orbiting the closest star to Earth, Proxima Centauri. The long-sought world, designated Proxima b, orbits its cool red parent star every 11 days and has a temperature suitable for liquid water to exist on its surface. This rocky world is a little more massive than the Earth and is the closest exoplanet to us — and it may also be the closest possible abode for life outside the Solar System. A paper describing this milestone finding will be published in the journal Nature on 25 August 2016.

[...] At times Proxima Centauri is approaching Earth at about 5 kilometres per hour — normal human walking pace — and at times receding at the same speed. This regular pattern of changing radial velocities repeats with a period of 11.2 days. Careful analysis of the resulting tiny Doppler shifts showed that they indicated the presence of a planet with a mass at least 1.3 times that of the Earth, orbiting about 7 million kilometres from Proxima Centauri — only 5% of the Earth-Sun distance.

A note on the press release discusses the potential habitability of Proxima b, given that it is orbiting close to a red dwarf star:

[Continues...]

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.

A terrestrial planet candidate in a temperate orbit around Proxima Centauri (DOI placeholder) (DX)

Two more papers are available (currently in peer review). They discuss the habitability of Proxima b (at a site that appears to be dedicated to the subject).

Related: Internal Temperature of Exoplanets Could Determine Habitability Rather Than "Goldilocks" Distance

Previously: "Earth-Like" Exoplanet Found in Habitable Zone of Proxima Centauri


Original Submission   Alternate Submission

Related Stories

"Earth-Like" Exoplanet Found in Habitable Zone of Proxima Centauri 26 comments

Astronomers have reportedly discovered an Earth-like exoplanet in the habitable zone of Proxima Centauri, one of the closest stars to our Sun. However, the claim is based on an anonymous source who is said to have leaked the news ahead of an announcement by the European Southern Observatory:

[In] what may prove to be the most exciting find to date, the German weekly Der Spiegel [translation] announced recently that astronomers have discovered an Earth-like planet orbiting Proxima Centauri, just 4.25 light-years away. Yes, in what is an apparent trifecta, this newly-discovered exoplanet is Earth-like, orbits within it's sun's habitable zone, and is within our reach. But is this too good to be true? [...] Citing anonymous sources, the magazine stated:

The still nameless planet is believed to be Earth-like and orbits at a distance to Proxima Centauri that could allow it to have liquid water on its surface — an important requirement for the emergence of life. Never before have scientists discovered a second Earth that is so close by.

In addition, they claim that the discovery was made by the European Southern Observatory (ESO) using the La Silla Observatory's reflecting telescope. Coincidentally, it was this same observatory that announced the discovery of Alpha Centauri Bb back in 2012, which was also declared to be "the closest exoplanet to Earth". Unfortunately, subsequent analysis cast doubt on its existence, claiming it was a spurious artifact of the data analysis.

However, according to Der Spiegel's unnamed source – whom they claim was involved with the La Silla team that made the find – this latest discovery is the real deal, and was the result of intensive work. "Finding small celestial bodies is a lot of hard work," the source was quoted as saying. "We were moving at the technically feasible limit of measurement." The article goes on to state that the European Southern Observatory (ESO) will be announcing the finding at the end of August. But according to numerous sources, in response to a request for comment by AFP, ESO spokesman Richard Hook refused to confirm or deny the discovery of an exoplanet around Proxima Centauri.

[Continues...]

Internal Temperature of Exoplanets Could Determine Habitability Rather Than "Goldilocks" Distance 9 comments

A Yale researcher has published a study that suggests that because the presumed "self-regulating mechanism" for planetary internal temperature does not exist, the distance at which an exoplanet orbits its star might not matter as much as random factors such as giant impacts during the formation of the planet:

A new study, appearing in the journal Science Advances on Aug. 19, suggests that simply being in the habitable zone isn't sufficient to support life. A planet also must start with an internal temperature that is just right.

"If you assemble all kinds of scientific data on how Earth has evolved in the past few billion years and try to make sense out of them, you eventually realize that mantle convection is rather indifferent to the internal temperature," said Jun Korenaga, author of the study and professor of geology and geophysics at Yale. Korenaga presents a general theoretical framework that explains the degree of self-regulation expected for mantle convection and suggests that self-regulation is unlikely for Earth-like planets.

"The lack of the self-regulating mechanism has enormous implications for planetary habitability," Korenaga said. "Studies on planetary formation suggest that planets like Earth form by multiple giant impacts, and the outcome of this highly random process is known to be very diverse." Such diversity of size and internal temperature would not hamper planetary evolution if there was self-regulating mantle convection, Korenaga said. "What we take for granted on this planet, such as oceans and continents, would not exist if the internal temperature of Earth had not been in a certain range, and this means that the beginning of Earth's history cannot be too hot or too cold."

Can mantle convection be self-regulated? (open, DOI: 10.1126/sciadv.1601168)

[More..]

Proxima b May Have Oceans 9 comments

Researchers have calculated that Proxima b may have liquid water oceans on its surface, or even be an "ocean planet" based on larger estimates of its radius:

A rocky planet discovered in the "habitable" zone of the star nearest our Sun may be covered with oceans, researchers at France's CNRS research institute said Thursday. A team including CNRS astrophysicists have calculated the size and surface properties of the planet dubbed Proxima b, and concluded it may be an "ocean planet" similar to Earth.

[...] They calculated the radius was between 0.94 and 1.4 times that of Earth, which is 6,371 kilometres on average. Assuming a minimum radius of 5,990 km, the planet would be very dense, with a metallic core making up two-thirds of the entire planet's mass, surrounded by a rocky mantle. If there is surface water, it would not contribute more than 0.05 percent to the planet's total mass, the team said—similar to Earth, where it is about 0.02 percent.

In the larger planet scenario, with a radius of 8,920 km, Proxima b's mass would be split 50-50 between a rocky centre and surrounding water. "In this case, Proxima b would be covered by a single, liquid ocean 200 km deep," said the CNRS. "In both cases, a thin, gassy atmosphere could surround the planet, like on Earth, rendering Proxima b potentially habitable," it concluded.

The exoplanet has not been seen transiting Proxima Centauri, so further data about its size and composition will require the James Webb Space Telescope or other observatories to directly observe it.

Original article in French.

Previously: "Earth-Like" Exoplanet Found in Habitable Zone of Proxima Centauri
ESO Confirms Reports of Proxima Centauri Exoplanet


Original Submission

Dust Belts and Possible Additional Exoplanet Spotted Around Proxima Centauri 11 comments

The Atacama Large Millimeter Array (ALMA) has reported the detection of a dust belt around 1-4 astronomical units (AU) from Proxima Centauri, as well as a possible outer belt 30 AU away and an "unknown source" (possible exoplanet) about 1.6 AU away from the star. The data also show "a hint of warmer dust closer to the star".

Proxima b is 0.05 AU from Proxima Centauri, and is considered to be in the star's "habitable zone". The 1-4 AU belt on the other hand has a characteristic temperature of about 40 K, while the 30 AU outer belt would have a temperature of about 10 K. Neptune's moon Triton is roughly 30 AU from the Sun with a temperature of 38 K.

The 1-4 AU belt is estimated to contain 0.01 Earth masses of asteroids (primarily?) up to 50 km in diameter. By comparison, our main asteroid belt (including Ceres) is estimated to contain 4% of the Moon's mass, or about 0.000492 Earth masses (Ceres is about 0.00015 Earth masses, roughly a third of the main asteroid belt). A minimum estimate for the Kuiper belt's mass is 20x that of the main asteroid belt, or the equivalent of this newly detected dust belt around Proxima Centauri.

Astronomy Magazine has an interview with one of the co-authors, who noted another possible exoplanet at 0.5 AU:

High Levels of Ultraviolet Radiation Should Not Preclude Life on Exoplanets 10 comments

Alien Life Could Thrive On Four Earth-Like Planets Close To The Solar System, Says Study

Alien life could be evolving right now on some of the nearest exoplanets to our solar system, claim scientists at Cornell University in Ithaca, New York. Their proof is you.

It's been presumed that the high levels of radiation known to be bombarding many of the rocky Earth-like exoplanets discovered so far by astronomers precludes life, but that theory is turned on its head by new research published [open, DOI: 10.1093/mnras/stz724] [DX] in Monthly Notices of the Royal Astronomical Society.

In "Lessons from Early Earth: UV Surface Radiation Should Not Limit the Habitability of Active M Star System", the authors say that all of life on Earth today evolved from creatures that thrived during an era of much higher levels of UV radiation assault. So why not life on alien worlds? It also poses another question: does the evolution of life actually require high levels of radiation?

The exoplanets studied are Proxima b, TRAPPIST-1e, Ross 128 b, and LHS 1140 b.

Related: ESO Confirms Reports of Proxima Centauri Exoplanet
Proxima b May Have Oceans
Seven Earth-Sized Exoplanets, Including Three Potentially Habitable, Identified Around TRAPPIST-1
Possible Habitable Planet, LHS 1140b, Only 40 Light Years Away
An Earth-Like Atmosphere May Not Survive the Radiation in Proxima b's Orbit
Hubble Observations Suggest TRAPPIST-1 Exoplanets Could Have Water
Ross 128b: A Newly Discovered "Earth-Like" Exoplanet Orbiting a Less Active Red Dwarf
Another TRAPPIST-1 Habitability Study


Original Submission

Proxima Centauri b Confirmed Using VLT's ESPRESSO, Possible Third Exoplanet Found in System 3 comments

Proxima Centauri b confirmed as nearest exoworld

Four years ago, scientists made one of the most exciting exoplanet discoveries so far, a rocky planet similar in size to Earth orbiting the nearest star to the sun, Proxima Centauri. While the detection seemed solid, more confirmation is always good, and now the ESPRESSO spectrograph on the Very Large Telescope (VLT) in Chile has provided that extra and more detailed confirmation. The news was announced by the University of Geneva (UNIGE) on May 28, 2020.

[...] Proxima Centauri b is very similar in size to Earth, with a mass of 1.17 Earth masses. It orbits its star in only 11.2 days, in contrast to our Earth's year-long orbit around our sun. That means Proxima Centauri b is a lot closer to its star than Earth is to the sun. But, because the star is a red dwarf – much smaller and cooler than our sun – its orbit is indeed within the habitable zone of Proxima Centauri. Interestingly, Proxima Centauri b receives about the same amount of solar energy from its star that Earth does from our sun.

[...] The mass of Proxima b was previously estimated to be 1.3 Earth masses. The accuracy of the new measurement of 1.17 Earth masses is unprecedented, according to Michel Mayor, the "architect" of all ESPRESSO-type instruments:

ESPRESSO has made it possible to measure the mass of the planet with a precision of over one-tenth of the mass of Earth. It's completely unheard of.

The new confirmation of Proxima Centauri b is exciting, but there may be more surprises in store ... there is also possible evidence of another and smaller planet in the newest data. A secondary detection was also made, although it isn't certain whether it is actually a planet. If it is, it is even smaller than Proxima Centauri b. [...] If it is a planet, it would be more akin to Mars or Mercury in size and mass – estimated at a minimum Earth mass of 0.29 ± 0.08 – and orbits the star in only 5.15 days. It wouldn't be too surprising, though, in that low-mass stars like red dwarfs tend to have multiple planets in their systems. More observations will be required to either confirm or refute this possible second planet.

Journal Reference
Mascareño, A. Suárez, Faria, J. P., Figueira, P., et al. Revisiting Proxima with ESPRESSO, (https://arxiv.org/abs/2005.12114v1)

Proxima Centauri - Planetary system

Previously: ESO Confirms Reports of Proxima Centauri Exoplanet
Proxima b May Have Oceans
Dust Belts and Possible Additional Exoplanet Spotted Around Proxima Centauri
First Light for VLT's ESPRESSO Exoplanet Hunter
Very Large Telescope's ESPRESSO Combines Light From All Four Unit Telescopes for the First Time
Proxima Centauri's No Good, Very Bad Day
High Levels of Ultraviolet Radiation Should Not Preclude Life on Exoplanets
Icy second planet potentially spotted orbiting Proxima Centauri


Original Submission

Third Exoplanet Found Orbiting Proxima Centauri 11 comments

Earth-like planet spotted orbiting Sun's closest star

Astronomers have discovered a third planet orbiting Proxima Centauri, the star closest to the Sun. Dubbed Proxima Centauri d, the newly spotted world is probably a bit smaller than Earth, and well within the habitable zone of its host star — meaning that it could have oceans of liquid water that can potentially harbour life.

"It's showing that the nearest star probably has a very rich planetary system," says Guillem Anglada-Escudé, an astronomer at the Institute for Space Sciences in Barcelona, Spain, who led the team that in 2016 discovered the first planet to be seen orbiting Proxima Centauri.

Astronomer João Faria and his collaborators detected Proxima Centauri d by measuring tiny shifts in the spectrum of the star's light as the planet's gravity pulled it during orbit. The team used a state-of-the art spectrograph called ESPRESSO at the Very Large Telescope, a system of four 8.2-metre telescopes at the European Southern Observatory in Cerro Paranal, Chile. The results were published on 10 February in Astronomy & Astrophysics.

A candidate short-period sub-Earth orbiting Proxima Centauri

We detect a signal at 5.12 ± 0.04 days with a semi-amplitude of 39 ± 7 cm s−1. The analysis of subsets of the ESPRESSO data, the activity indicators, and chromatic RVs suggest that this signal is not caused by stellar variability but instead by a planetary companion with a minimum mass of 0.26 ± 0.05 M (about twice the mass of Mars) orbiting at 0.029 au from the star. The orbital eccentricity is well constrained and compatible with a circular orbit.

Previously: "Earth-Like" Exoplanet Found in Habitable Zone of Proxima Centauri
ESO Confirms Reports of Proxima Centauri Exoplanet
Dust Belts and Possible Additional Exoplanet Spotted Around Proxima Centauri
Icy second planet potentially spotted orbiting Proxima Centauri
Proxima Centauri b Confirmed Using VLT's ESPRESSO, Possible Third Exoplanet Found in System


Original Submission

This discussion has been archived. No new comments can be posted.
Display Options Threshold/Breakthrough Mark All as Read Mark All as Unread
The Fine Print: The following comments are owned by whoever posted them. We are not responsible for them in any way.
  • (Score: 2) by Celestial on Thursday August 25 2016, @05:25PM

    by Celestial (4891) on Thursday August 25 2016, @05:25PM (#393105) Journal

    Being so close to its sun, the planet must be blasted with a ton of radiation. Best to send the Hulk first.

    • (Score: 5, Informative) by martyb on Thursday August 25 2016, @05:57PM

      by martyb (76) Subscriber Badge on Thursday August 25 2016, @05:57PM (#393111) Journal

      Being so close to its sun, the planet must be blasted with a ton of radiation. Best to send the Hulk first.

      No, and Yes. Being a Red Dwarf [wikipedia.org], they generally emit much less radiation that our Sun:

      Red dwarfs are very-low-mass stars.[15] As a result, they have relatively low pressures, a low fusion rate, and hence, a low temperature. The energy generated is the product of nuclear fusion of hydrogen into helium by way of the proton–proton (PP) chain mechanism. Hence, these stars emit little light, sometimes as little as 1⁄10,000 that of the Sun. Even the largest red dwarfs (for example HD 179930, HIP 12961 and Lacaille 8760) have only about 10% of the Sun's luminosity.[16]

      On the other hand Proxima Centauri [wikipedia.org]:

      It has a mass about an eighth of the Sun's mass (M☉), and its average density is about 40 times that of the Sun.[nb 3] Although it has a very low average luminosity, Proxima is a flare star that undergoes random dramatic increases in brightness because of magnetic activity.[19] The star's magnetic field is created by convection throughout the stellar body, and the resulting flare activity generates a total X-ray emission similar to that produced by the Sun.

      So all is calm and mild, and then it is not.

      In case you were thinking how long it would take to get there... by some reports the fastest man-made object is the New Horizons [wikipedia.org] probe which made observations of Pluto:

      ... [it] was launched from Cape Canaveral Air Force Station directly into an Earth-and-solar escape trajectory with a speed of about 16.26 kilometers per second (58,536 km/h; 36,373 mph)

      Which is fast enough to take a lap around the Earth at the equator in under 45 minutes.

      Proxima Centauri is 4.25 light-years away, or about 40e+12 km. That implies New Horizons would take about 77,570 years to get there. Space is BIG!

      --
      Wit is intellect, dancing.
      • (Score: 2) by mcgrew on Thursday August 25 2016, @09:00PM

        by mcgrew (701) <publish@mcgrewbooks.com> on Thursday August 25 2016, @09:00PM (#393184) Homepage Journal

        According to the article I read, the exoplanet is getting the same amounts of radiation as the Earth does, in the same frequencies despite its small distance. But that's because a dwarf doesn't radiate much; you can't see it without a telescope from Earth, and it's the nearest star to the sun.

        Since it's a... I forgot what they call it, but it flashes, making the prospect of life there pretty bleak. Also consider that there are three planets in the solar system's habitable zone, but only one of them will support life.

        --
        mcgrewbooks.com mcgrew.info nooze.org
        • (Score: 2) by takyon on Thursday August 25 2016, @09:13PM

          by takyon (881) <reversethis-{gro ... s} {ta} {noykat}> on Thursday August 25 2016, @09:13PM (#393192) Journal

          They have assigned this object a minimum mass of 1.3 Earth masses, which could actually enhance its chances of habitability. Hopefully it turns out to be spinning and have a nice magnetosphere.

          Here's a comment I wrote on last week's Proxima Centauri article [soylentnews.org].

          --
          [SIG] 10/28/2017: Soylent Upgrade v14 [soylentnews.org]
          • (Score: 3, Informative) by deimtee on Friday August 26 2016, @01:21AM

            by deimtee (3272) on Friday August 26 2016, @01:21AM (#393274) Journal

            Just a deep enough atmosphere would ameliorate a lot of the radiation from flares. Even Earth's atmosphere is roughly equivalent to 10 metres of water as shielding.
            The main benefit of a strong magnetic field is to stop the solar wind stripping the atmosphere.

            --
            If you cough while drinking cheap red wine it really cleans out your sinuses.
        • (Score: 2) by martyb on Friday August 26 2016, @01:00AM

          by martyb (76) Subscriber Badge on Friday August 26 2016, @01:00AM (#393267) Journal

          mcgrew (701) wrote:

          According to the article I read, the exoplanet is getting the same amounts of radiation as the Earth does, in the same frequencies despite its small distance. But that's because a dwarf doesn't radiate much; you can't see it without a telescope from Earth, and it's the nearest star to the sun.

          I doubt it would radiate in the "same frequencies" — as noted in my GP comment, it's a Red Dwarf [wikipedia.org]. I'll quote part of the section on "Habitability":

          An additional difficulty is that red dwarfs radiate most of their electromagnetic energy as infrared light, whereas plants on Earth capture most of their energy from the visible spectrum. Red dwarfs emit almost no ultraviolet light, which would be a problem, should this kind of light be required for life to exist.

          So, nothing like the same frequencies as our sun, sorry.

          Since it's a... I forgot what they call it, but it flashes, making the prospect of life there pretty bleak. Also consider that there are three planets in the solar system's habitable zone, but only one of them will support life.

          Quoting again from the GP comment which already noted:

          Proxima is a flare star that undergoes random dramatic increases in brightness because of magnetic activity.

          (More info in Wikipedia's entry on Flare Star [wikipedia.org].)

          That said, I'll whole-heartedly agree that the prospect for life there is quite bleak indeed. Though, there is the possibility that instead of being tidally locked with the same face always turned to its star, it might be more like our planet Mercury which, IIRC, is in a 3:2 resonance with the Sun. There's so much we don't know, but one can hope for more information from the huge new optical telescopes which are slated to be completed within the next decade or so.

          --
          Wit is intellect, dancing.
  • (Score: 3, Redundant) by maxwell demon on Thursday August 25 2016, @06:02PM

    by maxwell demon (1608) on Thursday August 25 2016, @06:02PM (#393112) Journal

    OK, it's nice that ESO confirms it, but …

    Does Netcraft confirm it?

    --
    The Tao of math: The numbers you can count are not the real numbers.
  • (Score: 1, Troll) by donkeyhotay on Thursday August 25 2016, @07:06PM

    by donkeyhotay (2540) on Thursday August 25 2016, @07:06PM (#393145)

    Keep dreaming.

    It's like exoplanetology is sort of a new religion. But heck, no problem in sending a small probe, if it doesn't cost too much.

     

    • (Score: 4, Interesting) by takyon on Thursday August 25 2016, @08:29PM

      by takyon (881) <reversethis-{gro ... s} {ta} {noykat}> on Thursday August 25 2016, @08:29PM (#393169) Journal

      What's "pie in the sky"? Sending humans there?

      All that's really needed is life extension or a little deep freeze. We'll likely have that worked out before the century is over, or even before 2050.

      5% speed of light average (going from 0 to 0.1c and back to 0 maybe?) would be an 85 year trip. There are a few propulsion methods that might make it possible. Advanced ion drives, fusion rockets, and emdrive seem like the top contenders (to be clear, emdrive is the bottom top contender, and will probably never work). Energy source should be nuclear decay or fusion.

      Shielding for interstellar particle hazards is an engineering problem. We could embed a ship in a small asteroid and use that for shielding.

      There is no need to rush, because the star is getting closer to Earth ever so slightly:

      Proxima Centauri will move closer to the Earth over the next 26,700 years at a rate of 22.4 km/s, until its closest approach of 3.11 light years.

      Long before any manned mission gets planned, our understanding of the planet's atmosphere, temperature, and possible lifeforms will be a top focus for our next-generation space observatories and ground telescopes [nextbigfuture.com]. In particular, the James Webb Space Telescope [wikipedia.org], the unnamed successor to James Webb (such as ATLAST [wikipedia.org] or HDST [wikipedia.org]), Giant Magellan Telescope [wikipedia.org], and European Extremely Large Telescope [wikipedia.org]. This exoplanet is now probably on par with Planet Nine [wikipedia.org] in terms of imaging importance.

      Once we have confirmed where it actually is, its mass and radius, composition of the atmosphere, any possible satellites it might have, the presence of liquid water on the surface, the presence of life/vegetation on the surface, and other planets in the Proxima system, then we can talk or whine about manned missions.

      --
      [SIG] 10/28/2017: Soylent Upgrade v14 [soylentnews.org]
      • (Score: 4, Disagree) by TrumpetPower! on Thursday August 25 2016, @10:15PM

        by TrumpetPower! (590) <ben@trumpetpower.com> on Thursday August 25 2016, @10:15PM (#393211) Homepage

        Sorry to burst your bubble, but humans ain't never no way nohow ever going to any other stars, period, full stop, end of story.

        The energy budget to send a spacecraft the size of the shuttle (which has about as much living space as a schoolbus) so it arrives in a mere decade is roughly the same as our entire civilization's energy budget.

        You suggest going slower using cryonics. That's a nice idea at first blush...but now you're pushing the travel time out closer to the age of our civilization itself...and the thought that anything technological will survive the harshness of interstellar space over such timescales is laughable. All your plastics and rubber will have long since crumbled into dust. Your hydrogen will all have leaked out of your steel tanks. Your circuitry will be completely fried by cosmic rays.

        The other popular suggestion is a generation ship that takes as long as cryonics. But now you need just as much total energy as the fast version, plus you've got to keep a modern manufacturing civilization going in perfect isolation for longer than (did I mention?) civilization has existed in the first place.

        Interstellar travel doesn't even begin to make sense until you've got a sizable fraction of a star's energy output to play with...at which point the Fermi Paradox slaps you full in the face. If you're using up your star that fast, you're on an exponential growth curve. Your main interest in interstellar travel will be to get to another star you can use to sustain your growth before you use up your own star. But even if you assume that the process to colonize another star takes (repeat after me) as long as our civilization has existed, you're going to run out of stars in the galaxy in far less time than our species has existed. And even if it takes as long as our species has existed, you're again running out in much less time than since the asteroid wiped out the dinosaurs.

        (Take however long you think it takes to colonize a star and multiply by 26 and that's how long until all the stars in the galaxy are colonized.)

        Since it's pretty clear that all the stars in this or any other galaxy have not been converted into Dyson Spheres, we can be overwhelmingly certain that that's not something that happens.

        So...yeah. Interstellar travel makes for great space opera, but it has exactly as much to do with reality as faery dust that makes you fly and instructions to turn right at the third star and go straight until morning, where you'll meet hook-armed crocodile pirates....

        Cheers,

        b&

        --
        All but God can prove this sentence true.
        • (Score: 1) by cyberthanasis on Friday August 26 2016, @09:51AM

          by cyberthanasis (5212) on Friday August 26 2016, @09:51AM (#393417)

          humans ain't never no way nohow ever going to find out what any other stars are made of, a prominent scientist said at the beginning of last century.
          Then spectroscopy did exactly that.

    • (Score: 2) by takyon on Thursday August 25 2016, @08:31PM

      by takyon (881) <reversethis-{gro ... s} {ta} {noykat}> on Thursday August 25 2016, @08:31PM (#393170) Journal

      If exoplanetology is a religion, I am the high priest who is going to ra...

      Oops, that's politically incorrect. Err... pray with me, child.

      --
      [SIG] 10/28/2017: Soylent Upgrade v14 [soylentnews.org]
  • (Score: 2) by takyon on Thursday August 25 2016, @08:41PM

    by takyon (881) <reversethis-{gro ... s} {ta} {noykat}> on Thursday August 25 2016, @08:41PM (#393173) Journal

    "Earth-Like" Exoplanet Found in Habitable Zone of Proxima Centauri [soylentnews.org]

    Yes, it MIGHT be habitable. If nothing else, it's a chance for us to focus our scopes on a relatively close exoplanet.

    One in Five Stars Has Earth-sized Planet in Habitable Zone [keckobservatory.org]

    Most stars have planets in habitable zone [earthsky.org] (Researchers calculate that billions of stars in our Milky Way galaxy have 1-3 planets in the habitable zone, where there may be liquid water and life.)

    If we discover an oxygen-rich atmosphere and liquid water on Proxima b, then we'll have another hint that there's potentially a LOT of life in the galaxy. As for the Fermi Paradox... well, if planets are hosting no more than microbes and plants for some reason, it's ripe for the taking.

    I guess one concern is that the predominant red dwarf stars or tidal locking of planets cause conditions that are hostile to the evolution of life, but might not be so bad for human settlers with a solar weatherman telling them to go inside their shielded homes. Or maybe there are plenty of radio signals bouncing around our galaxy but we are just plain shit at detecting them. Or advanced civilizations tend to destroy themselves. In that case, full speed ahead at getting off this rock...

    --
    [SIG] 10/28/2017: Soylent Upgrade v14 [soylentnews.org]
    • (Score: 2) by bob_super on Thursday August 25 2016, @09:36PM

      by bob_super (1357) on Thursday August 25 2016, @09:36PM (#393199)

      You can't say that! There can't be other viable planets in the whole universe!
      See: "This planet is a very special place custom-made for us by God Herself" - extract for the Proximabian Koran.

      • (Score: 2) by takyon on Thursday August 25 2016, @10:06PM

        by takyon (881) <reversethis-{gro ... s} {ta} {noykat}> on Thursday August 25 2016, @10:06PM (#393209) Journal

        One thing that might help explain the Fermi Paradox: Red dwarf stars are the predominant star type in the galaxy and the Universe. Life is less likely to form on planets orbiting red dwarf stars because of some combination of low energy (low T!), tidal locking, and deadly flare-ups, but if macroscopic life or humans traveled to these planets, they would find it a lot easier to deal with the flare-ups than burgeoning microbes would.

        --
        [SIG] 10/28/2017: Soylent Upgrade v14 [soylentnews.org]
    • (Score: 2) by AthanasiusKircher on Friday August 26 2016, @12:35AM

      by AthanasiusKircher (5291) on Friday August 26 2016, @12:35AM (#393257) Journal

      If we discover an oxygen-rich atmosphere and liquid water on Proxima b, then we'll have another hint that there's potentially a LOT of life in the galaxy.

      Well, I'd put a strong emphasis on that potentially. More accurately, if we discover oxygen and water, then we'll have another hint that there are more habitable planets for life somewhat like us in the galaxy.

      If you pay close attention to this stuff, it seems like almost every other week in the past few years there's some new observation about the history of earth and how there might be all sorts of conditions necessary for life that we haven't really considered before.

      Personally, I'd be thrilled to find that all it takes is a bit of water and oxygen in the right orbit and "poof!" life appears in a billion years or so. But there are likely thousands of little details necessary to the process of abiogenesis that we don't understand yet, and any one of them that's particularly sensitive to conditions could change the chance of life evolving on a planet like this from near certain to 1 in a billion (or 1 in a quadrillion).

      As for the Fermi Paradox... well, if planets are hosting no more than microbes and plants for some reason, it's ripe for the taking.

      The Fermi "Paradox" is only a paradox if you assume that P(life evolving on a planet with minimal earth-like conditions) is not much less than 1. But we have only one data point for that supposition, with little knowledge of what constitutes sufficiently "earth-like," and therefore no reason to assume that P here is 1 in 10 or 1 in 1000 or 1 in a quadrillion.

      • (Score: 2) by deimtee on Friday August 26 2016, @01:17PM

        by deimtee (3272) on Friday August 26 2016, @01:17PM (#393457) Journal

        Personally, I'd be thrilled to find that all it takes is a bit of water and oxygen in the right orbit and "poof!" life appears in a billion years or so.

        You shouldn't be. The answer to the Fermi question is known as "the great filter". It is the unknown factor that filters out potential space-faring aliens.
        It is either something in our past that is incredibly unlikely to be survivable (but we did - yay us!), or something in our future that is incredibly likely to kill us all before we start star travel (so sad).
        Something in our past is the more hopeful scenario.

        --
        If you cough while drinking cheap red wine it really cleans out your sinuses.
  • (Score: 2) by PartTimeZombie on Thursday August 25 2016, @08:44PM

    by PartTimeZombie (4827) on Thursday August 25 2016, @08:44PM (#393176)

    I was struck by how poor the reporting has been about this. Not the links above, but the TV news in particular. One idiot on TV last night informed us that a journey to "another galaxy" would take many years.
    As if Proxima is in another galaxy.

    • (Score: 0) by Anonymous Coward on Friday August 26 2016, @01:29AM

      by Anonymous Coward on Friday August 26 2016, @01:29AM (#393278)

      One idiot on TV last night informed us that a journey to "another galaxy" would take many years.

      Technically, he's right, if a bit understated.

      As if Proxima is in another galaxy.

      Of course being right doesn't mean he's not an idiot.

  • (Score: 0) by Anonymous Coward on Thursday August 25 2016, @09:16PM

    by Anonymous Coward on Thursday August 25 2016, @09:16PM (#393195)

    Look how quickly humans have developed technology since the steam engine was invented less than 320 years ago.

    Aren't we worried that aliens will come along and do a Hollywood sci-fi flick number on us?

    • (Score: 4, Interesting) by takyon on Thursday August 25 2016, @10:03PM

      by takyon (881) <reversethis-{gro ... s} {ta} {noykat}> on Thursday August 25 2016, @10:03PM (#393208) Journal

      Nah. We've already had retired Air Force officers speak out at places like the National Press Club and say that UFOs are probably alien spacecraft and have caused nuclear missile sites to malfunction.

      In the light of allegations like that, there are a few questions to consider:

      1. Are we being visited by aliens right now?
      2. Is faster-than-light travel possible?
      3. If no to #2, are aliens really close by? (instead of Proxima Centauri b proximity, say, within 100 light years)

      Imagine that faster-than-light travel is never invented, but we undergo another 1,000 years of technological development without destroying ourselves. The humanity of 3016 would be able to SPAM humans or bots or uploaded minds or whatever to every nearby star. We would be able to colonize "Earth-like" planets with our fleshy bodies, sure, but we'd also be able to put robots or enclosed human habitats on every rock. We'll send something to literally every rock within our solar system within the next 200 years. Ceres, Pallas, Enceladus, Europa, Pluto, Charon, Sedna, whatever, we will be able to put a probe or tiny base on it. The humans of the next millennium will be able to put a presence on every rock out to 10-25 light years, and will begin to reach objects that are 100 light years or more away.

      If we were to be scared of life that may be on Proxima Centauri b, it would likely have to be life that didn't originate there. Let's say we discover life on Proxima b by 2025. The first telescopes were created around 1608 (Galileo made his in 1609). That's 417 years from the invention of the telescope to the detection of life on an exoplanet 4.25 light years away.

      If Proxima b has a native-born population of alien life, they aren't likely to be at the same stage of development as us. They either discovered the telescope and built space observatories a long time ago, and discovered the watery Earth in their stellar backyard, or are too rudimentary (at the stage of microbes or lungfish) to do anything. If Proxima b is occupied by non-native life, then they can travel to Earth just as easily as we would be able to travel (spam) to other stars in the coming centuries. Another factor to consider is that Proxima Centauri is getting closer to the Sun, and was once further away. It will be around 3.11 light years from the Sun at closest approach in around 27,000 years.

      If we are already being visited, and it's not just crazies spouting off, then it's a wrap. Aliens can clearly get to Earth. If faster-than-light travel (such as a warp drive) is possible, then it's even more of a wrap, since they could arguably get here in a convenient manner, and on a whim. Since there is no widespread acceptance that we are being visited by aliens, we have to rely on detecting life on other planets using our next generation telescopes. We should have some answers within the next 2-3 decades.

      And to bring in the Fermi Paradox, one of the popular explanations for detecting no signals (since we are at a point where we now think that almost every star in the galaxy has a rocky planet in the habitable zone) is that civilizations tend to wipe themselves out. We have reached a point on Earth where we are still stuck on or near Earth (not even colonizing or traveling back to the nearby Moon), despite any efforts of NASA or Elon Musk or whomever. But we have plenty of nuclear weapons, and some exciting new biological weapons coming now that we are gaining a greater understanding of genomics. Even if we do manage to make a small and self-sustaining colony on Mars, it would take a long time for such a colony to gain a deep foothold on Mars and repopulate the Earth in the case of widespread disaster there. Humanity is still fragile.

      So no, I'm not really worried about aliens within the nearest 100 light years. They are either already visiting, don't exist, can't do shit, or won't do shit. And if they were close to us in terms of technological development but could reach us fairly quickly with slower-than-light travel, they'd already have the upper hand and there's nothing we can do but bulk up our own technologies. Luckily, the first ships capable of traveling here in such a #rare scenario would be the least capable in terms of energy and weapons.

      --
      [SIG] 10/28/2017: Soylent Upgrade v14 [soylentnews.org]
      • (Score: 2) by deimtee on Friday August 26 2016, @01:28PM

        by deimtee (3272) on Friday August 26 2016, @01:28PM (#393462) Journal

        The ability to travel to another star system pretty much automatically includes the ability to wipe out life on any planet you can reach. If you have a starship drive then it is no big deal to drop a rock that makes the Chicxulub impact look like a pebble in a pond.

        --
        If you cough while drinking cheap red wine it really cleans out your sinuses.
    • (Score: 0) by Anonymous Coward on Friday August 26 2016, @09:43AM

      by Anonymous Coward on Friday August 26 2016, @09:43AM (#393414)

      Aren't we worried that aliens will come along and do a Hollywood sci-fi flick number on us?

      https://en.wikipedia.org/wiki/Venus_and_the_Seven_Sexes [wikipedia.org]