Jupiter

For two months running we are fortunate to have the largest of our solar system’s gas giants put on stunning displays.

Where in August Saturn was at opposition, Jupiter will also be at its nearest and brightest to Earth on the night of September 26. Unlike the Saturnian opposition, however, when the moon lit up the sky on August 14 at 93% full, in the coming opposition backyard astronomers the world over will appreciate the darkness afforded by a new moon.

The ancient Romans gave Jupiter its name in honor of their chief god. This naming pattern parallels the Grecian title Zeus, the Babylonian designation Marduk, the Sanskrit honorific Brihaspati, and the Hebrew title Tsedek. Mùxīng, as it is known in Chinese, is so important in that culture’s mythology that the entire zodiac revolves around the approximately twelve-year cycle of Jupiter’s orbit around the Sun.

If one was able to take all the “stuff” in the solar system, excluding the Sun, and push it together into a giant ball, Jupiter would still be more than twice as large as everything else combined. Even the smallest of telescopes and binoculars can pick out the four Galilean moons orbiting the planet, though with larger scopes one can begin to resolve many more of its 79 known satellites. On clear nights you may also start to notice colored bands across the surface of the planet. These are clouds of gas, like jet streams on Earth, with currents moving in different directions in colors ranging from white to orange and brown.

The Juno spacecraft arrived in Jovian orbit in 2016 and has been studying the planet in detail ever since. While your backyard observations will be in the visible-light spectrum, Juno is able to study Jupiter’s gravitational and magnetic fields using the microwave, infrared and ultraviolet spectra. In addition, the new James Webb Space Telescope has already gazed at Jupiter in the infrared, allowing scientists to merge data across the spectrum to understand more about how this giant planet formed and continues to evolve as the defender of our inner solar system today.