Look to the east: Jupiter to be observably brightest Monday

If you gaze to the east at midnight today with a pair of binoculars, you’ll get a once-a-year peek of Jupiter — and four of its 79 moons — at its brightest point, according to Michael Cobb, Southeast Missouri State University professor of physics.

Jupiter’s viewable moons today will be Io, Europa, Ganymede and Callisto.

The four moons are called the Galilean Satellites, Cobb said, since astronomer Galileo Galilei was the one who first documented them.

Galileo — born Feb. 15, 1565 — was an Italian scientist and scholar, credited for modern physics and astronomy’s groundwork.

And with a telescope, Cobb said, several more moons also will be evident. The planet has no solid surface — nothing but clouds and weather.

“Earth and Jupiter are on the same side, opposite the sun, so that means Jupiter is closest to earth and therefore looks bigger and brighter,” he said, “and we call that ‘opposition.’”

But some years are a little bit better for viewing than others, Cobb said.

For viewing, Cobb said the darker the place the better. When the sun sets tonight, Jupiter will rise, with highest elevation being at midnight, “the best time” to observe, he said.

According to the National Weather Service, tonight the sky will be clear.

“But it’ll be worthwhile to look for a couple of weeks,” Cobb said, adding Jupiter is viewable 11 months out of the year.

“It’s good to look at no matter when,” he said.

Cobb said Jupiter’s Great Red Spot won’t necessarily be viewable, since it’s “never as prominent as you see photographs of.” The human eye is not sensitive to colors at low light levels, he said.

And, Cobb added, for the last several years or so, the size of the spot has been shrinking.

“It’s an anticyclone, and it’s been raging for 300 years,” Cobb said. “And so I guess all good things come to an end.”

He added scientists do not currently know what is causing the spot’s retreat.

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