Lunation Matrix
30.09.2022

Observe the Moon every night and you'll see its visible sunlit portion gradually change. In phases progressing from New Moon to Full Moon to New Moon again, a lunar cycle or lunation is completed in about 29.5 days.

Moon Pairs and the Synodic Month
25.09.2020

Observe the Moon each night and its visible sunlit portion will gradually change. In phases progressing from New Moon to Full Moon to New Moon again, a lunar cycle or synodic month is completed in about 29.5 days.

Eclipse on the Water
11.06.2021

Eclipses tend to come in pairs. Twice a year, during an eclipse season that lasts about 34 days, Sun, Moon, and Earth can nearly align. Then the full and new phases of the Moon separated by just over 14 days create a lunar and a solar eclipse.

Moons of Saturn
16.10.2019

On July 29, 2011 the Cassini spacecraft's narrow-angle camera took this snapshot and captured 5 of Saturn's moons, from just above the ringplane. Left to right are small moons Janus and Pandora respectively 179 and 81 kilometers across, shiny 504 kilometer diameter Enceladus, and Mimas, 396 kilometers across, seen just next to Rhea.

Moonless Meteors and the Milky Way
12.08.2015

Have you watched the Perseid meteor shower? Though the annual shower's predicted peak was last night, meteor activity should continue tonight (August 13/14), best enjoyed by just looking up in clear, dark skies after midnight. Of course, this year's Perseid shower has the advantage of being active near the August 14 New Moon.

Hubble Resolves Expiration Date For Green Cheese Moon
1.04.2002

Using the new camera on the recently refitted Hubble Space Telescope, astronomers have been able to confirm that the Moon is made of green cheese. The telling clue was the resolution of a numeric date after which the Moon may go bad.

APOD: 2025 March 3 Б Blue Ghost on the Moon
2.03.2025

There's a new lander on the Moon. Yesterday Firefly Aerospace's Blue Ghost executed the first-ever successful commercial lunar landing. During its planned 60-day mission, Blue Ghost will deploy several NASA-commissioned scientific instruments, including PlanetVac which captures lunar dust after creating a small whirlwind of gas.

Mercury as Revealed by MESSENGER
22.07.2017

Mercury had never been seen like this before. In 2008, the robotic MESSENGER spacecraft buzzed past Mercury for the second time and imaged terrain mapped previously only by comparatively crude radar. The featured image was recorded as MESSENGER looked back 90 minutes after passing, from an altitude of about 27,000 kilometers.

Full Observatory Moon
26.01.2024

A popular name for January's full moon in the northern hemisphere is the Full Wolf Moon. As the new year's first full moon, it rises over Las Campanas Observatory in this dramatic Earth-and-moonscape. Peering from the foreground like astronomical eyes are the observatory's twin 6.5 meter diameter Magellan telescopes.

Hubble Resolves Expiration Date For Green Cheese Moon
1.04.2006

Using the new camera on the Hubble Space Telescope, astronomers have been able to confirm that the Moon is made of green cheese. The telling clue was the resolution of a marked date after which the Moon may go bad.