A Nasa space telescope has delivered the first weather forecast from a planet outside our Solar System.
Scientists are keen to understand weather systems on exoplanets
The world, known as Upsilon Andromedae b, orbits close into a star that is 380 trillion km from Earth.
The Spitzer Space Telescope has been able to detect distinct day and night temperatures on the planet.
The results, reported in the journal Science, suggest weather systems transport very little heat from one side of the planet to the other.
This means one face of the planet is blisteringly hot, while the other is frigid in comparison.
"Such a large difference between the day and night sides reveals very interesting things about how heat and air masses flow on the planet. It makes for a very unusual climate and weather on this planet," said co-researcher Dr James Cho from Queen Mary University of London, UK.
The models produced thus far by scientists to describe the weather systems on such planets predict there should be very strong winds redistributing heat around the globe.
But Spitzer's measurements suggested atmospheric gases were instead absorbing and re-radiating sunlight rapidly, said study leader Dr Joe Harrington, from the University of Central Florida in Orlando, US.
The finding represents the first time that any kind of variation has been seen across the surface of an extrasolar planet (also sometimes called exoplanet).
Previous measurements have described only global traits, such as diameter and mass.
Upsilon Andromedae b was first discovered in 1996 around the star Upsilon Andromedae. It is what is known as a "hot-Jupiter" planet, because it is made of gas like our Jovian giant, and is hot, due to its tight, 4.6-day-long journey around its star.
The planet orbits its star at one-sixth the distance of Mercury from our own Sun.
Since the first planet orbiting another sun-like star was discovered in 1995, more than 200 such objects have been found.