In Brief
- The pace of extrasolar planet discovery is about to explode, thanks to a new space-based observatory.
- Models now predict that rocky planets larger than Earth may have a lively geology and stable atmospheres and climates.
- Some of these “super-Earths” could be hospitable to life.
Imagine yourself gazing at the sky on a summer night. You look in the direction of a particular star that, you have heard, has a special planet orbiting around it. Although you cannot actually see the planet—you can barely see the star itself—you know it is several times larger than Earth and, like Earth, is made mostly of rock. Quakes sometimes shake its surface, much of which is covered by oceans. Its atmosphere is not too different from the one we breathe, and its sky is swept by frequent storms and often darkened by the ash of volcanoes. But most of all, you know that scientists think it could harbor life—and that they plan to seek evidence for it.
This scenario could become reality within the next decade. Although most of the 450-odd extrasolar planets found so far are giants more similar to Jupiter, astronomers are beginning to discover some that may not be too different from Earth. And NASA’s Kepler probe, a planet hunter sent aloft last year, will discover many more.
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21 Comments
Add CommentI'd like to see an ultra-long baseline interferometer, using telescopes at the L5 and L6 trojan points either for the earth-moon or sun-earth systems. The lunar version would have a baseline of about 400000 miles and the earth-sun version would have a baseline of about 250,000,000 miles. Even with the loss of a few magnitudes of resolution due to various factors, it appears to this non-physicist that this baseline would allow useful remote observation of the surface features of planets in other systems. I believe that our laser technology is approaching the point where we could might be able to approach the necessary phase matching within a few years.
Reply | Report Abuse | Link to thisOOps. I totally mixed km and miles. The lunar distance would be on the order of 665 million km, the earth-sun distance would be about 250 million km using back-of-the-envelope calculations.
Reply | Report Abuse | Link to thisDang! earth-moon would be 665 THOUSAND km.
Reply | Report Abuse | Link to thisI doubt we will call these planets our home...
Reply | Report Abuse | Link to this... although maybe our descendants might. I'm just setting my sites on reaching 100 years old- I can't imagine we'll be on any other planets in that time, nor even setting off to colonize one.
I wish the editors of SciAm would prevent authors from using
Reply | Report Abuse | Link to thisthe articles as advertisements for their own careers. The old
SciAm discussed science, not the history of the author's
decisions to become brilliant (in their own humble words
of course).
Could the 'dimming technique' be used for other purposes, such as gathering info on the Kuiper Belt and Oort cloud objects?--i.e., could you track dark objects across a bright background, instead of the usual other way around?
Reply | Report Abuse | Link to thisInteresting for sure, though in truth I'd rather see our space activity for the near future focus on the commercial development of space. Once we have a genuinely permanent system of space stations in Geosynchronous orbit; one(s) to which we regularly travel and upon which researchers live and work for long stretches, and from which we conduct both scientific and industrial research on a scale that is comensurate with the scale of space, it will be a great time to begin the engineering, construction and operation of really big instruments for exploration.
Reply | Report Abuse | Link to thisIf we accept that space research, as it historically always has been, will always seem way too expensive but in actuality be consistently underfunded, then creating a system whereby launching a pound of propellant into space no longer costs $10,0000 but instead costs about $100, and thereby reflects the actual amount of fuel it takes to achieve orbit, and not the incredible overhead costs of our present system, should be our immediate goal.
At that point we will finally have something equivalent to a railroad to space, and a system that will get us where the view will give a good prospect on our future as a space faring civilization.
Rob44 - Well said!
Reply | Report Abuse | Link to thisI also find it interesting that the statement 'Scientists think...' has been superseded by 'Models now predict' for inferring automatic credibility to any statement. It makes no difference what the theoretical or pragmatic methodology of these unmentioned models, they are unquestionably accurate...
This article argues that "Super Earths" might be more congenial to life than our smaller size earth. But wouldn't the increased gravity of these super earths also hold more hydrogen gas than our smaller earth. How is more hydrogen and maybe even methan gas more condusive to life?
Reply | Report Abuse | Link to thisthere may likely be an abundance of ufo's, that know anything we build and do in space. evidence is the huge apollo ufo seen by buzz armstrong. i do not support a broad space exploration conquest mission, because our surviveability is very unlikely with so much competition. instead i suggest urge that we initially build defenses that protect us from them. perhaps we could build torpedos to attack their space ships that are in our solar system and not communicating with us. ultimately making it impossible for them to stay near earth and observe us building a computer satellite system that would send people to the nearest earth like habitable planets discovered by this telescope. civilizations may become extinct not just from themselves developing atomic weapons, but because they did not take the time to learn how to protect themselves from otherwise benign appearing ufo's, that are observing gathering information about earth today.
Reply | Report Abuse | Link to thisI have to disagree David N'Gog, I believe that at the rate of destruction on this planet, we will be forced to to seek another means of survival. And, that other means will most likely be in the form of colonization of other planets. A not so recent program on either the science channel, history channel or Nat. Geo. channel stated that we have the technology to terraform Mars within a 5 year span. Thus, making Mars inhabitable by human beings. How accurate that was or was not, I am not certain. But, that was 2 or 3 years ago. Technology has only gotten more advanced since then. Certainly, you also are aware of the death of our oceans due to pollution and other destructive means created by humans. I could go on, but I believe you get the point. We just don't have any other choice but to seek other living arrangements. This planet is almost shot, kaput, gone, etc.
Reply | Report Abuse | Link to thisRod.
I have to disagree David N'Gog, I believe that at the rate of destruction on this planet, we will be forced to to seek another means of survival. And, that other means will most likely be in the form of colonization of other planets. A not so recent program on either the science channel, history channel or Nat. Geo. channel stated that we have the technology to terraform Mars within a 5 year span. Thus, making Mars inhabitable by human beings. How accurate that was or was not, I am not certain. But, that was 2 or 3 years ago. Technology has only gotten more advanced since then. Certainly, you also are aware of the death of our oceans due to pollution and other destructive means created by humans. I could go on, but I believe you get the point. We just don't have any other choice but to seek other living arrangements. This planet is almost shot, kaput, gone, etc.
Reply | Report Abuse | Link to thisRod.
Sorry, it submitted twice that was an error.
Reply | Report Abuse | Link to thisRod
I have loved and been in awe of space since before Star Trek,but admit that this program fueled the smouldering embers of my interest.
Reply | Report Abuse | Link to thisSadly I think travelling to some far off habital planet is beyond us.Solely because,our offspring,who would arrive there would have only a video/audio history of their past. In reality they in fact would be alien to earth,never having lived there.I dare say there are many who think travelling by spaceship alone,without the aid of worm holes,or time machines is impractical and unachieveable.
Suppose though in 200 years offspring from a spaceship,do in fact land on another earth like planet,who's sun will obiviously have to have a life span greater than our own,otherwise what's the point.Which begs the question,if life as we know it has arrived at this stage,halfway through the life of our sun,is it the same for all earth like planets? Placng myself as one of the offspring,I think in time I would yearn to return to the place of my parents birth,to see and feel for myself how it differs to the one I call home.
Unless we can journey around our Galaxy in a matter of months,or rather weeks in the future,I feel, like all adventures, the exploration journey will be more enjoyable than arriving.
Has anyone calculated what we'd weigh on these planets?
Reply | Report Abuse | Link to thisThe article is very clear but it arise in my mind one question: the authors explain the wooble method and the transit method, but unfortunately they do not say anything about the way to detect if the variations in both methods are the product of one or some planets acting over the star. In my opinion, if there is one planet orbiting around a star, it is highly probable that another planets with different mass and density will be doing the same, altering the interaction between the star and its planets.
Reply | Report Abuse | Link to thisThis planet will be destroyed long before the Sun has a chance to go redgiant... Populating the galaxy is a must.
Reply | Report Abuse | Link to thisas much as I would LOVE to see it in my lifetime, I doubt it will happen
Reply | Report Abuse | Link to thisThis article talks about what the effect of being a larger rocky planet has on the core of the planet.The current theory of the creation of the moon is that a Mars sized proto-planet collided with the proto-Earth in such a way as to strip off a large amount of surface light material which condensed into the moon. In this case, Earths core, a combination of both proto-planet's cores, would be relatively larger than in other rocky planets forms without this kind of major collision. I'd like to know how that effects the Author's assumption of what the size of the core of heavier Earth-like planets would be, and how it would effect plate tectonics and the magnetic field.
Reply | Report Abuse | Link to thisThe models of super-earths predict planets with thick atmospheres and massive oceans. So these atmospheres contain probably water molecules and OH fragments.
Reply | Report Abuse | Link to thisThis presence of water and OH in atmosphere, particularly in upper part, could facilitate the detection of these super-earths by a phenomenon discovered thirty years ago.
The astronomer Michael Mumma and his team have discovered in 1981 (*) a natural laser emission produced by the Martian upper atmosphere. This very fine emission ray centered on 10,33 �m is due to carbon dioxide, majority component of the Martian atmosphere. This natural laser emission has been not only confirmed by other teams but another natural laser has been discovered in the Venusian upper atmosphere.
These discoveries suggest that this phenomenon of stimulated emission generated by a planetary atmosphere could be frequent.
The watery atmosphere of a super-earth could emit this sort of stimulated emission, but in radio domain. The water molecule and the radical OH generate maser rays at 22 GHz and 1.66 GHz. As the stars emit little in this part of electromagnetic spectrum, one can hope a ratio of brightness more favorable for the planet detection.
The masers emitted by water and radical hydroxyl could be a new way for the detection of super-earths.
(*): "Discovery of Natural Gain Amplification in the 10-Micrometer Carbon Dioxide Laser Bands on Mars: A Natural Laser"; MICHAEL J MUMMA, DAVID BUHL, GORDON CHIN, DRAKE DEMING, FRED ESPENAK, THEODOR KOSTIUK, and DAVID ZIPOY; Science, 3 April 1981, Vol. 212, No 4490, pp. 45 49.
The same thought occurred to me. Maybe the conclusion regarding the rapid orbits of some of these planets can be explained by the fact that the scientists are observing not one planet transit in front of the star, but more than one. Are the instruments accurate enough to measure a regular difference in the dimming observed between one observation and another?
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