With news of new extrasolar planets being released nearly weekly, there is a general feeling that we are in the midst of a singular moment in cosmic discovery. And the news a few weeks ago of a planet that is about the same size as Earth has provided the sense that the discovery of a planet truly similar to Earth – one that could actually sustain life – is on the horizon.
But can we actually predict when the first Earth-like planet will be discovered? In a forthcoming paper in PLoS ONE (to be published October 4th), Greg Laughlin and I attempted to do this. This paper, A Scientometric Prediction of the Discovery of the First Potentially Habitable Planet with a Mass Similar to Earth, uses the properties of previously discovered exoplanets, including the year of their discovery, to estimate when the likeliest time of this potentially habitable planet will be discovered. (Greg writes about our paper here).
Spoiler: early to mid-2011.
Of course, it’s a bit more complicated than that, but here’s an overview of what we did. Using the properties of previously discovered exoplanets, we developed a simple metric of habitability for each planet that uses its mass and temperature to rate it on a scale of 0 to 1, where 1 is Earth-like, and 0 is so very not Earth-like. Plotting these values over time and taking the upper envelope yields a nice march towards habitability.
Using a simple bootstrap sampling analysis, we calculated when a logistic curve fit to such an upper envelope would get to a habitability of approximately 1. And the likeliest time is early to mid-2011, or more precisely, early May 2011. Of course, there are precision considerations, but we are heartened by recognizing that our method shows a 75% chance of such an announcement by the end of 2013 (which is when many astronomers predict such a discovery), and that February 2011 is when we are due for a large release of data and announcement by NASA’s Kepler mission. Our method, using only previous discoveries, accords well with such informed estimates.
Now, we wait and see how close our prediction actually is to reality.
Update: The paper has been officially published at PLoS ONE and can be found here.
Samuel Arbesman, & Gregory Laughlin (2010). A Scientometric Prediction of the Discovery of the First Potentially Habitable Planet with a Mass Similar to Earth PLoS ONE (in press) arXiv: 1009.2212v1


Cool … it’s always neat to find about new family.
The Earth like planet will most likely be discovered in orbit around a red dwarf star because current radial velocity methods are not anywhere near precise enough to detect an Earth like planet around anything larger than a red dwarf. So, the planet will be dark and gloomy, populated by pale skinned geeks, probably all male. Something to get excited about? Maybe not.
I always like the way you write.i am shocked at this amazing discovery.i wish i would be the first man to go there.
check out this review about the Earth like planet http://frupis.com/earth-like-planet-discovered/
There are millions of planets out there similar in size to earth, but for any form of life to evolve they need many more parameters to coincide with earth for life to exist. not in the next 1000 years will we find life other then that found on earth. it is also 100% certain we will never travel to another planet outside our solar system, they are billions of miles away and there is no energy source to power a rocket/spaceship to another solar system let alone get back to earth. with our fastest rocket today it would take 15000 years to get there, and another 15000 years to get back!!!!!
The first Earth like planet was discovered at the end of September 2010 orbiting around the star Gliese 581.
The first Earth like planet that is not tidally locked will be discovered around a main sequence, mid to late and metal rich, K dwarf, possibly Epsilon Indi, in eight months time.
The first Earth like planet with an oxygen rich atmosphere, one of more than ten percent, will be discovered around an early K or late G type dwarf, in 14 months time.
These are my amazing predictions and if they come to pass, as they surely will, worship me babes for I am the Kwisatz Haerach!