Jupiter will be closer to Earth on Monday than at any other time of the year, offering skywatchers a chance to see the planet at its biggest and brightest.
Jupiter can be seen with the naked eye. But with a pair of binoculars or a small telescope, NASA says it should be possible to see not only Jupiter itself but also its four largest moons — and perhaps even the bands of clouds that encircle the gas giant.
"Go outside a little while after the sun has set, look toward the east, and it will be the brightest thing," Irene Pease, an amateur astronomer in Brooklyn, New York, and president of the Amateur Astronomers Association of New York, said of Jupiter. "You might think it's a plane, but it won't move like a plane or blink like a plane."
Pease said Jupiter was her favorite planet to observe because its shifting moons made it so dynamic. "If you note the positions of the moons and look back an hour or two later, the positions of the moons will have changed," she said. "To actually see something like that is really neat."
Jupiter's close approach is known as opposition, meaning that Jupiter, Earth and the sun are briefly arrayed in a straight line — with Earth in the middle. Although opposition occurs only on a single day, NASA says the entire month or so before and after opposition makes for a good time to see Jupiter.
The fifth planet from the sun, Jupiter orbits our host star once every 4,333 days between the orbits of Mars and Saturn. It's the solar system's biggest planet, containing more than twice as much matter as all the other planets combined.
Jupiter is believed to have 79 moons. The four largest — Io, Europa, Ganymede and Callisto — are sometimes called the Galilean satellites because they were first observed by the Italian astronomer Galileo Galilei in 1610.
Want more stories about space?
- New Hubble Space Telescope photo is a 'living history book' of our universe
- Scientists finally solve the mystery of weird aurora-like lights in the sky
- The moon is shrinking, and a new study shows it's racked by moonquakes