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Another Earth-like planet discovered: How many more can astronomers find?

Another Earth-like planet has been discovered, prompting the question of whether the universe is littered with millions of planets similar to our own.

Astronomers with the University of Hawaii has reportedly discovered five planets just 12 light years away. According to astronomers, Tau Ceti — the star around which the planets orbit — now tops the list of best possible places to search for alien life.

The star’s distance places it just three times as far as our sun’s nearest stellar neighbor, Alpha Centauri. Its five planets are estimated to have masses between two and six times the mass of the Earth — making it the lowest-mass planetary system yet detected.

The international team of astronomers, from the UK, Chile, the USA, and Australia, combined more than six-thousand observations from three different instruments and intensively modeled the data. Using new techniques, the team has found a method to detect signals half the size previously thought possible.

The habitable zone is considered the preferred location in a star’s orbit for a world to support liquid water — a key ingredient for life.

The latest discovery comes as astronomers have spent much of 2012 analyzing data obtained by NASA’s Kepler Space Telescope. Researchers around the U.S. have unveiled findings that seem to expand the possibilities of planetary bodies.

Kepler is staring at more than 150,000 stars continuously. It detects exoplanets by noticing the tiny brightness dips caused when they transit — or cross the face of — these stars from the telescope’s perspective. The instrument generally needs to observe three such transits to spot a planet.

Still, it remains unclear how many of these planets are actually habitable. Kepler lacks the ability to discern between elements within the atmosphere of planets and elements that actually make up the planet. While astronomers have captured data that provides them with some insight, additional research is needed to determine the best candidates for life.

The latest study may build on previous techniques to determine whether an exoplanet maintains the necessary compounds to host life. According to Mikko Tuomi of the University of Hertfordshire, the team of astronomers discovered the latest star system by employing a new technique that could provide astronomers with new data.

“We pioneered new data modeling techniques by adding artificial signals to the data and testing our recovery of the signals with a variety of different approaches. This significantly improved our noise modeling techniques and increased our ability to find low mass planets,” said Tuomi.

“Tau Ceti is one of our nearest cosmic neighbors and so bright that we may be able to study the atmospheres of these planets in the not too distant future. Planetary systems found around nearby stars close to our sun indicate that these systems are common in our Milky Way galaxy,” added James Jenkins, Universidad de Chile and Visiting Fellow at the University of Hertfordshire.

For 2013 NASA plans to continue its search for exoplanets capable of hosting life. According to the U.S. space agency, the Ames Research Center will continue to oversee the key objectives of the mission. The program is expected to continue through  April 2016, after NASA announced the approval of the Kepler mission extension based on a recommendation from the Agency’s Senior Review of its operating missions.

“This has been a great year for NASA Ames,” said Center Director S. Pete Worden. “From the continuing discoveries by the Kepler mission, our key contributions to the Mars Science Laboratory Curiosity rover, and observations by SOFIA, our airborne infrared observatory, Ames remains at the forefront of exploration. In 2013, we will continue these exciting missions and contribute cutting-edge research and innovation to support NASA.”