Baby planets give glimpse into adulthood


Scientists have found a younger, hotter version of Jupiter.

It's one of two newly formed planets recently found -- one is bigger than Neptune, while the other is Jupiter-like.

The finds were published in Nature this week.

They're among the youngest ever detected, and have given scientists a peek into the lifecycles of planets.

The California Institute of Technology study shows a year on the Neptune-like planet is a short 5.4 days, with the planet orbiting a five- to 10 million-year-old star.

The planet is 50 percent larger than Neptune, and its mass less than 3.6 times that of Jupiter, though its true mass is likely to be similar to Neptune.

It shows large planets can exist close to their host star shortly after the star-forming nebular gas is dispersed.

The planet could still have some growing up to do, with its proximity to a mature, low-mass star being quite rare.

Meanwhile, a separate paper from the Université de Toulouse describes a 'hot Jupiter' in close orbit around a two million-year-old Sun-like star.

It lends weight to a theory that giant planets form as rotating disks of dense gas and dust which surround a new star, and move inward toward their host star, which happens early on in their formation.

The 'hot Jupiter' orbits its host star 100 times more closely than Jupiter orbits our Sun.

Scientists estimate Jupiter, the fifth planet from the Sun, is about 4.53 billion years old.