Sister Solar System and Earth's cousins

Solar system with seven Earth-sized exoplanets

The National Aeronautics and Space Administration (NASA) announced on February 23 the discovery of a solar system with seven Earth-sized exoplanets about 39 light years away from our sun. The discovery is being seen as very significant as the planets found orbiting dwarf star TRAPPIST-1 could potentially harbour life.

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Earth 2.0: NASA finds planet's 'cousin'

NASA announced the discovery of a planet in the Milky Way galaxy, 1400 light years away. The discovery is believed to be the closest to Earth so far.

In a press conference to announce the discovery of the exoplanet, John Grunsfeld, associate administrator for NASA's Science Mission Directorate in Washington, said the planet so closely resembled its cousin Earth that it was basically “Earth 2.0”.

The six billion-year-old planet, named Kepler 452B, was found to be 1.5 times the size of Earth and is likely to have a rocky surface. Jon Jenkins, a Kepler lead analyst at NASA revealed that the planet was at the right distance from the sun to support life and that it had an orbit that was similar to Earth with a 385-day year range. Jenkins added that the newly-discovered exoplanet received 10 per cent more energy from its star and had spent billions of years in the “goldilock’s zone” or habitable zone in its solar system, which means it could very well be habituated by life.

The discovery was made by the Kepler space observatory and was confirmed by the Hubble telescope and other Earth-based observatories. The spacecraft Kepler monitors stars’ light and notices the dip in light to discover planets when they cross in front of the star.

Responding to a question, Jenkins said that it would likely be possible for humans to adapt to the gravity on Kepler 452B which is twice the gravity on Earth. Although Jeff Coughlin, Kepler research scientist at SETI Institute in Mountain View, California , later added that it might well be a few generations before we’re able to land on the planet.

For now, it looks like even getting a closer look from the surface of Kepler 452B will take a while. “Just the speed that a spacecraft could get there, even if was travelling near to the speed of light, would take many decades," said Coughlin in response to a question about getting a camera or probe on to the surface.

So far, there has been no evidence of life on the planet although Kepler could have possibly have life and could also support photosynthesis and plant life, claimed Jenkins.

We are now aware of 12 planets that could potentially support life out of the thousands of planets that have been discovered since the first one was discovered outside our solar system 20 years ago.

(The article was published on Down To Earth on July 23, 2015)

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Most Earth-like planet yet spotted

There is exciting news for those looking for and wondering about potentially habitable planets outside our solar system. Scientists have discovered what they claim is the most Earth-like planet detected till date.

The planet, Kepler 186f, detected by NASA's orbiting Kepler telescope, is circling a red dwarf star, Kepler 186, some 500 light years away (one light year equals about 9.5 trillion km) and exists in the “Goldilocks zone” where it's neither too hot nor too cold. The planet, which is about 10 per cent larger than Earth, may very well have liquid water that makes life possible on Earth, scientists said. This is because it resides at the outer edge of the habitable temperature zone around its star — the sweet spot where lakes, rivers or oceans may exist without freezing solid or boiling away.

“Kepler 186f is the first validated, Earth-size planet in the habitable zone of another star,” said Elisa V Quintana of the SETI Institute and NASA’s Ames Research Center in Mountain View, California at a news conference on Thursday. “It has the right size and is at the right distance to have properties similar to our home planet.” Quintana said she considers the planet to be more of an "Earth cousin" than a twin because it circles a star that is smaller and dimmer than our sun. While Earth revolves around the sun in 365 days, this planet completes an orbit of its star every 130 days.



Kepler-186f is part of a system of five planets, all of which are roughly Earth's size. However, the other planets are too close to their star to support life.

Kepler 186f, named after NASA's Kepler planet finding mission, is too far away for astronomers to ascertain its mass, or if it has an atmosphere and supports life.

Kepler telescope examines Space for subtle changes in brightness that indicate an orbiting planet is crossing in front of a star. From those changes, scientists calculate a planet's size and make certain inferences about its makeup. 

Since its launch in 2009, Kepler has confirmed 961 planets, but only a few dozen are in the habitable zone. Most are giant gas balls like Jupiter and Saturn, and not ideal places for life.

(The article was published on Down To Earth on April 18, 2014)