Total Solar Lunar Eclipse
8.02.2018

This digitally processed and composited picture creatively compares two famous eclipses in one; the total lunar eclipse (left) of January 31, and the total solar eclipse of August 21, 2017. The Moon appears near mid-totality in both the back-to-back total eclipses.

The Far Side of the Moon
24.02.2007

Does this moon look familiar? Possibly not, even though it is Earth's Moon. Locked in synchronous rotation, the Moon always presents its well-known near side to Earth. But from lunar orbit, Apollo astronauts also grew to know the Moon's far side.

Lunar Eclipse over Cologne Cathedral
21.01.2019

Why would a bright full Moon suddenly become dark? Because it entered the shadow of the Earth. That's what happened Sunday night as the Moon underwent a total lunar eclipse. Dubbed by some...

An Etruscan Vase Moon Rising
22.02.2009

What's happened to the Moon? Nothing, although from some locations, February's full moon, which occurred about two weeks ago, appeared strangely distorted as it rose. Visible in particular was a curiously inverted...

Saturn and the Da Vinci Glow
3.05.2019

On February 2nd early morning risers saw Saturn near an old Moon low on the eastern horizon. On that date bright planet, sunlit crescent, and faint lunar night side were captured in this predawn skyscape from Bursa, Turkey. Of course the Moon's ashen glow is earthshine, earthlight reflected from the Moon's night side.

Julius Caesar and Leap Days
28.02.2020

In 46 BC Julius Caesar reformed the calendar system. Based on advice by astronomer Sosigenes of Alexandria, the Julian calendar included one leap day every four years to account for the fact that an Earth year is slightly more than 365 days long.

Moon Phases 2022
31.01.2022

What will the Moon phase be on your birthday this year? It is hard to predict because the Moon's appearance changes nightly. As the Moon orbits the Earth, the half illuminated by the Sun first becomes increasingly visible, then decreasingly visible.

Io and Callisto Mutual Event
25.11.2014

A 24 minute sequence from top to bottom, this intriguing series of telescopic frames tracks the occultation of Io by Callisto, two of Jupiter's Galilean moons, from San Pietro Polesine, Italy, planet Earth. A challenging observational project using a small telescope, the two contrasting Jovian worlds are both slightly larger than Earth's Moon.

APOD: 2023 November 28 Б Ganymede from Juno
27.11.2023

What does the largest moon in the Solar System look like? Jupiter's moon Ganymede, larger than even Mercury and Pluto, has an icy surface speckled with bright young craters overlying a mixture of older, darker, more cratered terrain laced with grooves and ridges.

A Fleeting Eclipse
27.08.1997

A lunar eclipse can be viewed in a leisurely fashion. Visible to anyone on the night side of planet Earth (weather permitting), totality often lasts an hour or so as the moon glides through the Earth's shadow. But a solar eclipse is more fleeting.