Moon and Jupiter

Until about 30 years ago, Jupiter was the king of the planets – bigger and heavier than any other known planet. Today, it’s not even in the top 500. It’s still the giant of our own solar system – it’s more massive than all the other planets and moons combined. But hundreds of planets in other star systems outrank it.

The total number of confirmed exo-planets is up to about 6,000. They range from chunks of rock about as massive as the Moon to super-planets up to about 80 times Jupiter’s mass.

Such giants are much easier to find than smaller worlds. Astronomers find most exoplanets in a couple of ways. One is to watch as a star fades a bit as a planet passes in front of it. Larger planets block more starlight, producing a bigger dip.

The other way is to measure a tiny shift in a star’s light caused by the gravitational pull of an orbiting planet. Heavier planets exert a stronger pull, making them easier to find.

Many of the “super Jupiters” are especially close to their parent stars. So these are the easiest planets to find. Over the years, though, the list of such planets in more-distant orbits has grown as well – bumping Jupiter farther from his throne as “king” of the planets.

Jupiter is still a giant presence in our sky. It looks like a brilliant star. And it’s close to the Moon the next couple of nights – to the upper left of the Moon tonight, and a little closer below the Moon tomorrow night.

Script by Damond Benningfield