Jupiter's Moons | Astronomy.com

A monochrome engraving depicts a person seated on a stool with their back turned, operating a large cone-shaped instrument pointing toward an open window in the background. The room is filled with scientific tools, including a tall wooden clock cabinet on the left wall, pendulums, and various instruments spread across the floor. Detailed cross-hatching creates high contrast, casting deep shadows across the dark interior while bright light streams in through the window pane.

Today in the History of Astronomy

Sept. 25, 1644: The birth of Ole Roemer

A small, blurry, strawberry-shaped blob glowing in warm orange and red tones sits centered within a dark square inset. Two faint, yellowish points of brightness stand out along its right edge, contrasting against the muted red body. The entire square frame is isolated against a solid black background, giving the object high contrast.

Today in the History of Astronomy

Sept. 9, 1892: Edward Emerson Barnard sees Amalthea

Today in the History of Astronomy

Jan. 7, 1610: Galileo sees four moons of Jupiter

Io’s magma ocean may not exist after all

Watch Jupiter’s moons in action this month

An illustration of NASA's Europa Clipper spacecraft above the surface of Europa and in front of Jupiter

Robotic Spaceflight, Solar System, Space Exploration

NASA’s Europa Clipper sets sail for Jupiter

Scientists view Ganymede’s aurorae dancing during eclipse

Map of Io's hot spots

Science, Solar System

First-of-its-kind map of Io’s volcanoes hints at subsurface magma ocean

Jupiter's moon Io

Jupiter’s moon Io has likely been active for our solar system’s entire history

Alien Life, Solar System

NASA’s Juno spacecraft probes Europa’s oxygen levels