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A Gliese Moment

Exoplanets are a niche topic for many people, rarely brought to mind except to note an occasional discovery before moving on to the rest of the day’s news. But Gliese 581 c is causing ripples. Yesterday, BBC radio host Eddie Mair referred to it as ‘the planet everyone is talking about.’ And last night on my regular walk I passed a neighbor I run into almost every evening. He was standing in his yard looking west under a sky dominated by an incredibly bright Venus. This is a man I have known for years, and not once in that time have we spoken about astronomy. But on this night, he said “So how do you pronounce G-l-i-e-s-e?”

I’ve always said ‘Glee-see,’ but as astronomer Wilhelm Gliese was German, the proper way to say it really should be ‘Glee-zuh’. Gliese (1915-1993) first came to my attention about twenty years ago when I was trying to work out the odds of picking up accidental radio emissions from civilizations near the Sun. The Gliese Catalog of Nearby Stars told me what was where, all known stars within 25 parsecs of the Sun.

That seemed pretty esoteric too, but this morning I passed another neighbor (I walk a lot, usually three or four miles a day). The sky was soft, tawny, criss-crossed with contrails and promising rain by evening. We exchanged pleasantries and talked about the new planet. What got her going was my use of the word ‘nearby.’ “You say it’s a nearby star. How long would it take to get there?” I told her 20 years if we could move at the speed of light and her eyes widened. “If that’s nearby,” she said, “I’d hate to know what you consider far away!” We both laughed and looked into the sky, shaking our heads at the sheer scale of things.

Maybe I’ve coined a new term — a ‘Gliese moment’ — that describes what happens when a formerly niche topic suddenly goes mainstream. In any case, what an opportunity to get people not normally involved with astronomy to acquaint themselves with what the exoplanet hunt is really about. This past decade of ‘hot Jupiters’ and outer system giants is giving way to a period when planets not much larger than ours will be swimming into view. Give us another decade and we may be looking at reflected light off a planet with an atmosphere, oceans and clear signs of life.

My unexpected conversations on this topic have completely delighted me. Because what I am picking up is the palpable sense of awe as people leave their daily concerns behind for a moment and start to think about just how big the universe is, where we might fit in it, and what else we might find as we push ever further out toward stars like Gliese 581. This new world was like finding an unexpected gift at the door, one that made these two people, both nearing retirement, feel enchanted with the cosmos again. As for me, Gliese 581 c, that distant world under a dim red sun, warm in places and maybe water-laden, has put a definite spring in my step. The hunt for terrestrial exoplanets has only begun.

Comments on this entry are closed.

  • larry April 26, 2007, 9:11

    As I was taking my teenage daughter to school she ask about potential “Glieseans” (spelling) aliens lifeforms. Hmm a potential 1st alien race name.

    Another interesting thought was if there were Moons around one of these super Earths.


  • Darnell Clayton April 26, 2007, 11:54

    So I am not the only one to see this!

    When I was at church last night, a few of the teenagers (who usually talk about the latest movie, music, hairstyle, etc.) were talking about…you guessed it, Gliese 581 c.

    We in fact had a hearty discussion about it, although I had to correct a rumor that grass was discovered upon its surface.

    I think they heard a report saying that there was a possibility for life on the world, with trees, flowers and grass, but I informed them that we do not have the technology to view atmospheres of these worlds–yet.

    Either way, this is a good distraction from the daily grind, although I wonder what will happen when scientists discover an Earth-like world around a yellow star, with an oxygen atmosphere?

  • Tenpin April 26, 2007, 11:57

    From the looks of it, people outside the space community are getting way ahead of themselves over this. This planet is probably as nightmarish as Venus, if not more so, but they’ve got visions of walking along alien beaches in their heads. It’s great that the usually dim public is having a gander, but they’ll probably be yawning from all the “new Earths” by the time we discover a real one.

  • Dunkleosteus April 26, 2007, 12:51

    Nice story, the mankind has some hope left.

    Tenpin: Yes, it is very possible that the planet is a terrible super-critical steam hothouse that immediately burns a hapless astronaut to death. It would be incredibly unlikely if the planet actually was livable.

    The main point about the discovery is that the planet conceivably could support life as it is most likely terrestrial and is located within the star’s habitable zone.

    Another very important point is that the star is a type of star which not a long ago by many was not believed to be hospitable for planets (metal-poor red dwarf). The pace of new Neptunes and super-Earths–despite the fact they’re much harder to detect–suggests that they are common. Perhaps much more common than Jovian planets.

  • stargazerdude April 26, 2007, 15:17

    If Man can survive our technological adolescence without blowing ourselves up… and the nihlists in the Middle East are prevented from grabbing headlines everyday with another horrific waste of humanity …and everyday be a Gliese moment, Lord that’s what I pray for.

  • Marc April 26, 2007, 15:21

    Yes, I’ve noticed how many people are talking about this to. On a website I work at called Simtropolis.com, they’re talking about how “awesome” this discovery is, and most of them think that we’ll get there in a few years. I guess they just don’t realize how massive the galaxy (not even the universe) truly is.

  • Marc Millis April 26, 2007, 15:46

    Even my wife, who was ticked-off at me the night before, brought up this discovery as an olive-branch moment to reopen civil communication.

    Peace on Earth from space!


  • Administrator April 26, 2007, 20:29

    Wow Marc, what a great story! But when I showed it to my wife, she said “If you think some alien planet is going to get you off the hook, you can forget it.” So it doesn’t always work…

  • Christopher L. Bennett April 26, 2007, 22:56

    Glad to hear some people are reacting to this with awe. On one of my main online boards, the reactions fall into two categories: either they want to dwell on what pop-culture concept it reminds them of (specifially the planet Krypton) rather than appreciate the world for what it is, or they’re expressing surprising mistrust and hostility toward the scientists along with gross misunderstandings, saying things like “Why are they only interested in planets like ours?” or “They shouldn’t jump to conclusions about whether a planet can or can’t support life!”

  • ljk April 27, 2007, 8:58

    Forget finding intelligent life in space – let’s figure out a way to
    keep our wives from being constantly ticked off at us first!

  • Administrator April 27, 2007, 12:11

    Christopher, it will be intriguing to follow public perception on this story. I hope you’ll keep us posted on what you’re seeing on your online forums as well.

  • andy April 27, 2007, 18:15

    Christopher – not entirely sure if I fit into the second of those categories: I’m a habitability-doubter and actually quite disappointed that important discoveries such as this one have been completely overshadowed by the habitability issue, when quite a simple calculation shows this planet receives greater stellar flux than Venus does.

    I now suspect that once the first truly habitable planet is found (I’m optimistic that it might well be the third planet of Gliese 581, but time will tell), it will be “old news” – after all, it’s now been discovered, according to the news stories that the general public will come across. And if further analysis of the conditions on the planet reach the media (which I suspect is doubtful, given the general standard of science reporting), and it turns out that there’s no way it can be habitable, it will probably lead to general public distrust about the results of the field of extrasolar planet research, especially since this planet has now seemingly entered the public conciousness.

  • Christopher L. Bennett April 28, 2007, 7:00

    ^^My point was that these people were mishearing the statements that the planet could conceivably be habitable as absolute assertions that it was. They were criticizing the scientists for saying something they weren’t actually saying at all.

    You do have a point about the dangers of jumping to conclusions about this planet, but I think it’s the reporters and the general public who are jumping to those conclusions, not the scientists themselves. As I read it, the scientific community’s excitement is not so much about 581 c itself as about what it represents — a sign that we now have the technology to detect Earthlike planets in habitable zones and may be close to finding one that could support life.

  • george scaglione April 28, 2007, 13:24

    yes christopher what you say can very easily be the case.it would be great for us all and as i have guessed in the past …maybe even a boost for the space program if we could find a truly earth like planet! as always,keeping an eye out for everyones comments. thank you very much your friend george

  • ljk May 3, 2007, 13:06

    Sunrise from the Surface of Gliese 581c

    Illustration Credit & Copyright: Karen Wehrstein

    Explanation: How might a sunrise appear on Gliese 581c? One artistic guess is shown above. Gliese 581c is the most Earth-like planet yet discovered and lies a mere 20 light-years distant. The central red dwarf is small and redder than our Sun but one of the orbiting planets has recently been discovered to be in the habitable zone where liquid water could exist on its surface.

    Although this planet is much different from Earth, orbiting much closer than Mercury and containing five times the mass of Earth, it is now a candidate to hold not only oceans but life enabled by the oceans. Were future observations to confirm liquid water, Gliese 581c might become a worthy destination or way station for future interstellar travelers from Earth. Drawn above in the hypothetical, the red dwarf star Gliese 581 rises through clouds above a calm ocean of its planet Gliese 581c.


  • promoton May 24, 2007, 12:56

    >Sunrise from the Surface of Gliese 581c

    I don’t think that picture is likely to be very accurate but who knows?
    The color of the star is off IMO as is the sky color. If there are oceans of liquid water (which is thought to be very likely) there would be a big reddish coloured atmosphere. But thanks. It’s amazing to think that whether any life exists there or not, the planet more than likely has astonishing views (possibility of a rich thick atmosphere, a sun disc that is very large in the sky, and a near by Neptune sized rocky (possibly with a ring, and undoubtedly beautiful even without)) and that really is something!! It’s inspiring. Let the Earth mass exoplanet revolution continue.

    Actually, because the innermost Neptune sized planet is not far away, and the star is not so bright, a visual eclipse with the naked eye would have to be possible. and maybe very often because of the radio orbital period of that planet (5 Earth days) and 581 C (13 days)

    Everyone’s been speculating about life in perpetual light because the planet may be tidally locked. Imagine a dramatic change in light up to 3 times a day!! There could in all reasonable probability be a very rapid change from twilight to daylight!!

  • GIVENCHY September 6, 2008, 9:11

    There seems to be alot of negative comments here about the general public taking an interest, why is this such a bad thing? Even if gliese is a “nightmare” planet there is still an outside chance that it is in the goldielocks zone, as such shouldnt we be be making every effort to increase public awareness about it?
    Furthermore at the risk of sounding completely mad should we not be looking to try and reach it?
    Doing some rough calculations, bearing in mind that I am no physics expert it would only take 6 months to reach a velocity of 0.9C under an acceleration of just 2g using t=(V-Vo)a and at this velocity it would take just 24 years to cover the 20 light years distance then another six months of deceleration, and bingo, And with special relativity the time for the people making the journey would seem like much less. I know that as you get close to 0.9c the energy put into maintaining the 2g would become very large due to e=mc2, however the amount of fuel required is probably less than the americans used while murd.. sorry I meant pacifying the middle east, And I know that there are alot of unknowns at travelling that fast but should we not at least try on the off chance, instead of just speculating?

  • Administrator September 6, 2008, 14:48

    I only wish a manned payload could be accelerated to an appreciable percentage of lightspeed for the cost of current US involvement in the Middle East. Unfortunately, the amount of fuel involved using current technologies is staggering. Here’s a bit on this from my Centauri Dreams book:

    “[An] efficient ion engine would need more than 500 propellant tanks the size of supertankers to complete an Alpha Centauri flyby within a century, according to NASA physicist Marc Millis… And the problems are only beginning. Slowing down takes as much propellant as speeding up; we must, therefore, push that much more fuel. If we wanted our spacecraft to stop once it reached Alpha Centauri, those five hundred supertankers would need to be supplemented by another three hundred million supertankers to make the 100-year journey and stop! As you keep adding more propellant to push still more propellant, the ratio of fuel to payload simply goes off the chart, an unfortunate fact that grows out of the equations that relate mass to velocity change…”

    Those equations are, I’m afraid, inexorable, which is why using rockets for interstellar purposes is widely considered the wrong approach, and why various sail concepts are making headway.

    Anyway, re cost, here’s one good reference that talks about the matter, examining the drain on Earth’s economy from an interstellar mission. Now this is for a laser-pushed lightsail, far more efficient than any rocket. Even so, Curt Mileikowsky worked out that 65,000 billion watts of installed electric power capacity would have to be supplied to the laser for 900 hours to build up the needed acceleration (and this is for a flyby, not a rendezvous mission). Total capital cost for electricity alone: $130 trillion.

    The paper is Mileikowsky, “How and When Could We Be Ready to Send a 1,000 KG Research Probe with a Coasting Speed of 0.3c to a Star?” Journal of the British Interplanetary Society 49 (1996): 335–44. Don’t get me wrong, there are differing viewpoints, but I cite Mileikowsky to show how daunting the challenge really is.

  • Bill October 4, 2010, 11:31

    Quote from several news sources:

    And the planet’s discoverers are optimistic about the prospects for finding life there.

    “Personally, given the ubiquity and propensity of life to flourish wherever it can, I would say, my own personal feeling is that the chances of life on this planet are 100 percent,” said Steven Vogt, a professor of astronomy and astrophysics at the University of California, Santa Cruz, during a press briefing today. “I have almost no doubt about it.”

    This is a bold statement, even if it is just personal feelings /opinion of the scientist. So I can see why some people on Christopher’s and other message boards may be getting the wrong idea. But really, when a discovery such as this is made, the scientific community should take greater care their statements made to the public. Many people have a difficult time distinguishing between hard facts and opinions in these matters, and the press core is just looking for a sound byte / headline.

  • Sebastian Mackedenski October 4, 2010, 18:08

    Gliese 581 is billions of years older than our own sun and presumably its rockstar plant “c” is among billions of years older than Earth; has had much longer for life to begin and evolve. This planet is bigger and more massive than Earth suggesting more raw primordial soup bowls pitting the face or interior caverns of this world increasing chances of life initiation. With temperatures on par with home, those reactions of life are not restricted to abstract liquid nitrogen solubilized mediums, suggesting equally rapid chemical reaction rates… but Gliese produces plenty of mutagenic x-ray and UV AND planet “c” (they really need a name already) is much closer to its star than Earth our own, suggesting overall more rapid evolutionary rates assuming hereditary genetic material resembles at some level, our own, including its radiation vulnerabilities (consider that a kingdom of life using a more resistant and durable form of genetic material, would evolve less quickly and likely be out competed by the more rapidly evolving creatures using a less stable “DNA equivalent” that is bound to spontaneously emerge throughout the planets very long history. In short every factor that pushed life into existence on this planet, is amplified there and this planet is gold! Probably teaming with beautiful forms of complicated, exotic life, if you want your children’s children’s “…” children to be rich outa there skulls, find the first printed article about this planet and vacuum seal it for them!

    If more advanced scans reveal no indicative traces of life, its because an advanced indigenous (or not) race likely entered a global holocaust rendering C an inhospitable wasteland. Sadly if in the not too distant future if all necessary materials for life are found on this planet, yet life is indisputably lacking, we are to inevitably drop considerably, the probability of finding life elsewhere as the odds would be proven very very low and we really did win the ultimate lottery.