What a photo! If you looked to the skies last night (January 21st), you may have noticed a bright point of light nearly on top of the Moon. That was Jupiter! Last night was the closest they will come (an event called “conjunction”) until 2026.
Their nearly intersecting “paths” through the sky are only due to our Earthly perspective, of course. Many things in the night sky will appear next to each other if we just wait long enough. What’s especially cool about this photograph is that it captures three levels of astronomical complexity in one image.
First we have our terrestrial satellite, Luna, with the “terminator" line of day/night stretched across a large, dark volcanic plain known as the “Ocean of Storms”, which is an awesome name for a volcanic plain. The next brightest image is Jupiter, our solar system’s largest planet/failed star. And those dots around Jupiter? Those are three of its Galilean moons! The photographer’s Facebook page says there’s four moons of Jupiter in this shot, but I only see three. If we are seeing them in their increasing distance from Jupiter (and that’s a big if, since perspective can play tricks on us), they are probably Io, Europa, and Ganymede.