Washington, Oct 4 : NASA’s Spitzer Space Telescope has revealed and Earth like planet forming 424 light-years away in a star system called HD 113766.

Agency astronomers have discovered a huge belt of warm dust – enough to build a Mars-size planet or larger – swirling around a distant star that is just slightly more massive than our Sun.

The dust belt, which they suspect is clumping together into planets, is located in the middle of the system's terrestrial habitable zone. This is the region around a star where liquid water could exist on any rocky planets that might form. Earth is located in the middle of our Sun's terrestrial habitable zone.

Scientists say, at 10 million years, the star is perfectly aged to form a rocky planet.

“The timing for this system to be building an Earth is very good. If the system was too young, its planet-forming disk would be full of gas, and it would be making gas-giant planets like Jupiter instead. If the system was too old, then dust aggregation or clumping would have already occurred and all the system's rocky planets would have already formed,” said Dr. Carey Lisse, of the Johns Hopkins University Applied Physics Laboratory, Laurel, Md.

Dr. Lisse said the conditions for forming an Earth-like planet are more than just being in the right place at the right time and around the right star – it's also about the right mix of dusty materials.

Using Spitzer's infrared spectrometer instrument, he determined that the material in HD 113866 is more processed than the snowball-like stuff that makes up infant solar systems and comets, which are considered cosmic “refrigerators” because they contain pristine ingredients from the early solar system.

However, it is not as processed as the stuff found in mature planets and the largest asteroids, which means that the dust belt must be in a transitional phase, when rocky planets are just beginning to form.

Dr Lisse said HD 113766 does not contain any water ice, carbonates or fragile organic materials.

He further said that unlike planets and asteroids, the metals in HD 113766 have not totally separated from the rocky material, suggesting that rocky planets have not yet formed.

“The material mix in this belt is most reminiscent of the stuff found in lava flows on Earth. I thought of Mauna Kea material when I first saw the dust composition in this system – it contains raw rock and is abundant in iron sulphides, which are similar to fool's gold,” said Dr. Lisse, referring to the well-known Hawaiian volcano.

“It is fantastic to think we are able to detect the process of terrestrial planet formation. Stay tuned — I expect lots more fireworks as the planet in

HD 113766 grows,” he said.

Dr. Lisse’s study is scheduled for publication in the upcoming issue of Astrophysical Journal. (With inputs from ANI)