Astronomers have found a planet that's a lot like a baby version of Jupiter. The new world, known as 51 Eridani b, is 100 light-years away and only 20 million years old - which by astronomical standards is just a toddler.

Image via BBC. Image 1.Image via BBC

The planet, discovered with the Gemini Planet Imager (GPI), shows the strongest methane signature ever detected on an alien planet, showing similarities to to the heavy methane atmospheres of planets in our solar system. The astronomers also detected water on the planet.

Most alien solar systems that we've discovered are very different from our own. They typically have massive planets orbiting close to their stars. Finding an alien solar system similar to ours - with small rocky worlds orbiting close to their star and gas giants orbiting at very far distances - is much rarer.

Astronomers are hoping that 51 Eridani b is young enough to give them clues about how it was created. "This planet really could have formed the same way Jupiter did; the whole solar system could be a lot like ours," said Bruce Macintosh from Stanford University's Kavli Institute.

Facts about the gemini planet imager:

 51 Eridani b was discovered using the Gemini Planet Imager (GPI) which is installed on the 8m Gemini South Telescope in Chile.

 GPI looks for faint, young planets orbiting bright, relatively nearby stars.

 GPI searchers for light from the planet itself (referred to as direct imaging) rather detecting dips in starlight as planets pass their suns, which is how many other scientific instruments find planets.

 Cover image: BBC