Scientists Predict Earth-Like Habitable Exoplanet Will Be Found in 2011


Two astronomers have written a paper and say that the first Earth-like, habitable exoplanet will be announced in May of 2011. Do they have inside information, a crystal ball, or amazing powers of prediction? No, they base their projection on math and trends from the past 15 years of exoplanet discoveries. And if the discoveries continue at their present rate, the researchers say next year is the year of the long awaited holy grail of finding another Earth-like planet out in the cosmos.

Samuel Arbesman from Harvard Medical School in Boston and Gregory Laughlin at the University of California, Santa Cruz take a scientometric approach to their prediction. Scientometrics is the science of measuring and analyzing science, and is often done using bibliometrics which is a measurement of the impact of scientific publications. Arbesman and Laughlin said this type of work highlights the usefulness of predictive scientometric techniques to understand the pace of scientific discovery in many fields.

They use the properties of previously discovered exoplanets along with external estimates for the discovery of the first potentially habitable extrasolar planet.

In their paper they indicate that since astronomers have been discovering extrasolar planets at an increasing rate since 1995 and the discoveries follow a well understood pattern, it should be easy to predict when planet searchers will hit the jackpot.

The first exoplanets found were the massive Jupiter or larger-sized planets which were the easiest to find, and then as techniques improved over the past 15 years, astronomers have found smaller planets, some just a few times more massive than Earth.

A single realization of the habitability of extrasolar planets over time. H values for the extrasolar planets are plotted, with those of the upper envelope (maximum H for a given year of discovery) indicated in black. The black curve is the logistic best- t curve of the upper envelope, using a nonlinear model, where R = 28:78 and y = 2011:10. The horizontal grey line indicates the maximum value of H = 1, the presence of an Earth-like habitable planet. Credit: Arbesman and Laughlin

Arbesman and Laughlin took that rate of discovery, and they also needed to factor in all the variables for what we think will make a planet habitable: the surface temperature must allow liquid water to exist, so that life as we know it can appear, and that depends on the size of the star, how far the planet orbits from its star, and what type of surface the exoplanet has.

They conclude there is a 66 per cent probability of finding another Earth by 2013, a 75 per cent probability by 2020, and a 95 per cent probability by 2264, but the median date of discovery is in May 2011. And not just sometime in May, but “early May.”

In June 2010, the Kepler Telescope team revealed they had found 750 exoplanet candidates, and a fair number of those confirmed might be Earth-sized. They expect they can confirm and announce some of these candidates in February 2011. But Arbesman and Laughlin predict it might take longer. “Because of the limited time base line of the mission to date, the Kepler planet candidates to published in February 2011 may be too hot to support significant values for H (which is their habitability metric),” they wrote in their paper.

So, if their prediction comes true, that might mean another team, such as the HARPS, or Keck, or CoRoT, or other exoplanet-finding wizards might make the discovery.

“It must be noted that by publicizing our prediction, there is a concern that it will become accurate,” Arbesman and Laughlin write in their paper, “simply due to the well-studied Hawthorne Effect. However, due to the large number of observations and long periods of time required to confirm an extrasolar planet discovery, it is unlikely that our prediction at this time will appreciably affect the announcement of the discovery of an Earth-like planet. Therefore, it is reasonable to use the habitability metric curve as a rough prediction for when the first potentially habitable planet will be discovered, in this case, as early as May 2011, and likely by the end of 2013.”

It will be interesting to see how accurate their prediction turns out to be!

Read the paper: “A Scientometric Prediction of the Discovery of the First Potentially Habitable Planet with a Mass Similar to Earth.”

Additional Source: Technology Review Blog

12 Replies to “Scientists Predict Earth-Like Habitable Exoplanet Will Be Found in 2011”

  1. Exciting news! I like the paper, including the habitbility metric which reminds of Mendez’, but suited to the question in hand of course. Duly bookmarked.

  2. sooo, first habitable planet – CHECK
    what will be next? first planet, that is in the habitable zone for at least a billion years?

  3. “sooo, first habitable planet – CHECK
    what will be next?”

    ummm, first inhabited planet! 🙂

  4. Perhaps I’m missing something, but if there is a 66 percent probability of discovering an earth sized exoplanet by 2013 and a 75 percent probability by 2020, how are they arriving at a discovery by 2011? Also, a small nitpick. I believe we’re closer to discovering an earth- sized, rather than an earth-like body. AFAIU, we’re much more adept at calculating mass than atmosphere at this point. Nonetheless, exciting news. With the current rate of discovery and advancing technology, it shouldn’t be long before we’re able to make a really earthshattering(no pun intended) discovery.

  5. Very nice. Oddly this is about the time I have wagered a bet with someone on the timing of such news (spring 2011 – late 2012) (he believes none exist lol).

    Easy money coming my way soon…

  6. “Perhaps I’m missing something, but if there is a 66 percent probability of discovering an earth sized exoplanet by 2013 and a 75 percent probability by 2020, how are they arriving at a discovery by 2011?”

    Say you repeated this experiment many times – looking for an exoplanet with the same characteristics of Earth, with the same probability of finding it in a given time frame as calculated in the article for each experiment. Then May 2011 would be when they would find the planet on average. There would be a 50% chance of finding it before that date in any of the experiments (it is the median date for discovery) and a 50% chance for finding it sometime after that date. Therefore, you could expect that it would be found at that date on average in any given experiment – i.e. our observations.

  7. Renoor makes a valid point. A planet may be similar to Earth, but if is gravitationally pulled over millions of years to different orbits due to gas giants might not have life.


  8. rRenoor makes a valid point, but it is already answered by Jon. The next step is to look for atmospheres in major chemical imbalance due to life metabolism.

  9. so what are we going to do? find this planet, go there, and pollute & destroy it in the same way we are this one?!

  10. I don’t know what you are going to do (but how will you get there?), but I assume the rest of us will be inspired by knowing that we aren’t alone, along outstanding question, and by more input on habitability and abiogenesis areas.

  11. I wrote a book on the physics of sending probes to nearby stars. It should be possible to send a probe within 25 light years with a gamma < 1.2, and out to maybe 50 light years with a gamma ~ 2. In the last case it would take about 100 years to get a signal back.



    Something tells me that the harsh and economical realities of life in space during the voyage, and then on the planet itself once the colony was founded, would preclude the “pollute, destroy, and discard” philosophy practiced by most Earthlings. Recycling would practically be something to be worshiped aboard a starship and on an exoplanet colony.

    Think of it like Japan before globalization happened – isolation combined with limited resources leads to smaller things uses more efficiently – or not, at your own peril.

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