The planet Jupiter is basically a big ball of gas. It consists mainly of hydrogen and helium, the lightest of all elements.
Yet there’s so much of these elements that Jupiter is the 800-pound gorilla of the solar system. It’s about two and a half times as massive as all the other planets and moons combined.
That gives Jupiter a powerful gravitational pull. And the planet puts that gravity to use — and always has. In the early solar system, Jupiter kicked billions of “leftover” balls of rock and ice into deep space. Some of them orbit the Sun from great distances, but others were ejected from the solar system entirely.
Jupiter still has that kind of influence today. It pushes comets and asteroids into new orbits. And it sometimes rips them apart, or pulls them to their doom by dragging them into the planet itself.
Because of that influence, astronomers must consider Jupiter’s pull when they calculate the orbits of the other planets, moons, and smaller bodies. And engineers have to keep it in mind when they launch spacecraft to other parts of the solar system — the giant influence of a giant planet.
And Jupiter is putting in a giant appearance right now. The planet is at opposition — it’s lining up opposite the Sun. It rises around sunset and is in view all night long. It also shines brightest for the year. It’s low in the southeast at nightfall and looks like a brilliant star.
More about Jupiter tomorrow.