An Etruscan Vase Moon Rising
23.02.2009

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
4.05.2019

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
29.02.2020

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
1.02.2022

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
28.11.2023

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.

Space Station Silhouette on the Moon
6.12.2021

What's that unusual spot on the Moon? It's the International Space Station. Using precise timing, the Earth-orbiting space platform was photographed in front of a partially lit gibbous Moon last month.

A Fleeting Eclipse
8.06.2002

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.

Julius Caesar and Leap Days
29.02.2024

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.