Proxima Centauri Has Planet in Habitable Zone

The European Southern Observatory (ESO) has made the long-awaited announcement. At their website they have this headline: Planet Found in Habitable Zone Around Nearest Star. Here are some excerpts, with bold font added by us:

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.

There’s already a news item that appears in Nature: Earth-sized planet around nearby star is astronomy dream come true, and you can read without a subscription. We’ll stay with the ESO announcement. They say:

Just over four light-years from the Solar System lies a red dwarf star that has been named Proxima Centauri as it is the closest star to Earth apart from the Sun. This cool star in the constellation of Centaurus is too faint to be seen with the unaided eye and lies near to the much brighter pair of stars known as Alpha Centauri AB.

[…]

Guillem Anglada-Escudé explains the background to this unique search: “The first hints of a possible planet were spotted back in 2013, but the detection was not convincing. Since then we have worked hard to get further observations off the ground with help from ESO and others. The recent Pale Red Dot campaign has been about two years in the planning.”

The Pale Red Dot data, when combined with earlier observations made at ESO observatories and elsewhere, revealed the clear signal of a truly exciting result. 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.

Guillem Anglada-Escudé comments on the excitement of the last few months: “I kept checking the consistency of the signal every single day during the 60 nights of the Pale Red Dot campaign. The first 10 were promising, the first 20 were consistent with expectations, and at 30 days the result was pretty much definitive, so we started drafting the paper!”

Let’s read on:

Although Proxima b orbits much closer to its star than Mercury does to the Sun in the Solar System, the star itself is far fainter than the Sun. As a result Proxima b lies well within the habitable zone around the star and has an estimated surface temperature that would allow the presence of liquid water. Despite the temperate orbit of Proxima b, the conditions on the surface may be strongly affected by the ultraviolet and X-ray flares from the star — far more intense than the Earth experiences from the Sun.

What about habitability? ESO continues:

Two separate papers discuss the habitability of Proxima b and its climate. They find that the existence of liquid water on the planet today cannot be ruled out and, in such case, it may be present over the surface of the planet only in the sunniest regions, either in an area in the hemisphere of the planet facing the star (synchronous rotation) or in a tropical belt (3:2 resonance rotation). Proxima b’s rotation, the strong radiation from its star and the formation history of the planet makes its climate quite different from that of the Earth, and it is unlikely that Proxima b has seasons.

Here’s one more excerpt:

Guillem Anglada-Escudé concludes: “Many exoplanets have been found and many more will be found, but searching for the closest potential Earth-analogue and succeeding has been the experience of a lifetime for all of us. Many people’s stories and efforts have converged on this discovery. The result is also a tribute to all of them. The search for life on Proxima b comes next…”

So there it is. Close enough for exploration, although that will take quite a bit of time. Now we await the response from the creationists.

Copyright © 2016. The Sensuous Curmudgeon. All rights reserved.

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20 responses to “Proxima Centauri Has Planet in Habitable Zone

  1. The important question is what to name this planet.

  2. @TomS:

    Perhaps it already has a name. Who knows?

    Of course, the inhabitants might not use sound waves to communicate, but rather form their “words” with rapidly-changing color patterns on their external covering, similar to certain species of squid.

    Realistically, though, it’s very doubtful that there is life on this planet, let alone intelligent life. But again, who knows?

  3. Waiting for Ken Ham to pour some cold liquid water on this report.

  4. Astronomers using ESO telescopes and other facilities have found clear evidence of a planet orbiting the closest star to Earth, Proxima Centauri.
    Unfortunate that an astronomical group like the ESO cannot get it right. I think old Sol is a shade closer than Proxima Centauri.
    Oh, yes, and surely the most critical thing is to find a name for this planet.

  5. I think the possibility of microbial life is maybe 50/50 – life could have formed before the planet became tidally locked and then adapted as conditions slowly changed. It doesn’t seem like larger multicellular life would be there, but we really don’t know much about the planet at all yet.

  6. The planet already has been named: the unimaginative Proxima b. I have read a rumour that a probe will send within 20 years; the journey might take about 30 years.
    I hardly can’t await Ol’ Hambo’s reaction. Fortunately I always can rely on our dear SC for this.

  7. mnb0 says: “I hardly can’t await Ol’ Hambo’s reaction. Fortunately I always can rely on our dear SC for this.”

    Ol’ Hambo gives us a clue in his latest blog post: Did Venus Once Support Life? After dismissing speculations that Venus may once have had life — because it’s all speculation — he concludes by saying:

    When we start with God’s Word, we get an entirely different interpretation regarding Venus. Our Creator designed Venus on Day Four of Creation Week just a few thousand years ago. Since Earth, not Venus (or any other planet), was designed to be inhabited (Isaiah 45:18), our presupposition implies that we wouldn’t expect to find life on Venus in the past or the present. Now this is entirely different from the evolutionary expectation, but the difference isn’t in the evidence. The difference is in the worldview and presuppositions of the person interpreting the evidence.

  8. @Hambo

    The difference is in the worldview and presuppositions of the person interpreting the evidence.

    This is surely the exact antithesis of the scientific approach, and yet Hambo claims to love science. Oh, dearie me.

    @retiredsciguy

    Realistically, though, it’s very doubtful that there is life on this planet, let alone intelligent life. But again, who knows?

    You’d better watch it. That last sentence will have KevinC accusing you of both wild speculation and putting your faith in Proxima b being inhabited.

    Assuming that Proxima b is uninhabited, surely that presents just as much a problem for the creationists as would its being inhabited. After all, if it’s empty of life, what did the creator actually make it for?

  9. …not Venus (or any other planet), was designed to be inhabited…

    So if life is found on another planet, the bible is wrong? Ham seems to be backing himself into a corner here.

  10. Doctor Stochastic

    Earth like Planet.
    Planet like Earth.
    Make many Moons.

  11. Even if it turns out that Proxima b does have life, creationists won’t be fazed. They’ll just say the planet’s life forms were created by God 6,000 years ago like the rest of the universe. There’s no changing the minds of true fanatics.

  12. If the planet is shown to have life, it is one of those features that are best explainable by an intelligent cause. If it doesn’t, we’ll have to check our design filter to be sure. There might still be some complex specified information! Who knows?

  13. A name?

    How about, New Beginnings!??

    (I know its been done, but it was good there too.)

  14. Dave Luckett

    I understand that Proxima Centauri is the third star in the system, after Alpha and Beta, approximately 15000 AU distant from them, with an orbital period about some common point of not less than 500 000 years. The distance from Proxima to the other members of the system is a therefore bit more than that of Saturn from our sun. Alpha is a little larger than our sun, Beta a little smaller, but brighter.

    That seems to me to imply that Alpha and Beta would appear from Proxima b as appear as something we don’t see in our sky – two small, but very bright lights with disks that can be resolved by the naked eye, but whose movement could not be discerned by normal means in any human lifespan, hence, “fixed”.

    Humans would quite likely see them as two eyes glaring down. I wonder if there is an intelligent species on Proxima, how they see them?

  15. “yet Hambo claims to love science.”
    I have learned that this is an excuse to reject those parts that are inconvenient.

  16. @Dave Luckett

    Saturn’s only about 10 AU from the sun.

  17. @Dave – seeing Alpha Centauri A&B from Proxima is something we might be able to simulate in the planetarium. Good idea.

    The view back toward Sol is also interesting – https://upload.wikimedia.org/wikipedia/en/6/6d/Sky-from-alpha-centauri.jpg

  18. Dave Luckett

    @realthog: Doh! What is this thing arithmetic? Can you eat it?

  19. “The difference is in the worldview and presuppositions of the person interpreting the evidence.” Ken Ham as quoted by Realthog.
    Normally Ham detests evidence – though sometimes he cherry picks from evidence, i.e. ‘fossils exist ergo Noah’s worldwide Flood was a real historical event.” In this case, Ham is willfully ignoring the reams of evidence that the solar system is billions of years old, Thus he rails against simulations of what Venus may once have been like (even if they could be wrong and are not dogmatic in nature). Ham thinks he knows it was always just like it is today. Although he has no evidence for that assumption – just a ‘biblical worldview’.

  20. The astronomer Sean Raymond suggests (in a February 2015 article) that we’re perhaps being overly pessimistic about the possibility of life on a “hot eyeball” (tidally locked) planet such as Proxima b almost certainly is. He makes a good case.