2019 October 5
Explanation:
After sunset on October 3, some of the Solar System's largest moons
stood low along the western horizon with
the largest planet.
Just after nightfall, a pairing of the Moon approaching first quarter
phase and Jupiter was captured in this telephoto field of view.
A blend of short and long exposures, it reveals
the familiar face
of our fair planet's own large natural satellite in stark sunlight and
faint earthshine.
At lower right are the ruling gas giant and its four Galilean moons.
Left to right, the tiny pinpricks of light are
Ganymede, [Jupiter], Io, Europa, and Callisto.
Our own natural satellite appears to loom large because it's close,
but Ganymede, Io, and Callisto are actually larger than Earth's Moon.
Water world Europa
is only slightly smaller.
Of the Solar System's six
largest planetary satellites,
only Saturn's moon Titan, is missing from this scene.
But be sure
to check for large moons
in your sky tonight.