A planet 100 light-years away resembles an infant version of Jupiter, astronomers say.
The new world, known as 51 Eridani b, is only 20 million years old – a toddler by astronomical standards.
The alien world could yield clues to the formation of our Solar System, which has an unusual lay-out.
The find was made by the Gemini Planet Imager (GPI), which looks for faint, young planets orbiting bright, relatively nearby stars.
The new world shows the strongest methane signature ever detected on an alien planet. Previous Jupiter-like exoplanets have shown only faint traces of methane, making them very different from the heavy methane atmospheres of gas giants in our Solar System.
The astronomers also detected water, using GPI’s spectrometer instrument.
These findings indicate that it might be similar to planets in our Solar System, yielding additional clues to the formation of giant, astronomical bodies.
The vast majority of alien solar systems that have been discovered are very different from our own, with massive planets – so-called “hot Jupiters” – orbiting close to their stars. This is partly because such systems are easier to detect with the techniques currently used to search for planets orbiting distant stars.
“Previous search methods couldn’t find systems like our own, with small, rocky worlds close to their star and large, gas giants at large distances like Jupiter and Saturn,” said co-author James Larkin, from the University of California, Los Angeles (UCLA).
“The search for large planets at large separations from their star is exactly the goal of GPI. These solar systems are likely much more similar to our own.”
Studying such worlds should reveal how common our Solar System architecture truly is.