Alphonsus and Arzachel
17.07.2021

Point your telescope at tonight's first quarter Moon. Along the terminator, the shadow line between night and day, you might find these two large craters staring back at you with an owlish gaze. Alphonsus (left) and Arzachel are ancient impact craters on the north eastern shores of Mare Nubium, the lunar Sea of Clouds.

APOD: 2023 May 9 Б Shadows of Earth
9.05.2023

Can you find two Earth shadows in today's image? It's a bit tricky. To find the first shadow, observe that the top part of the atmosphere appears pink and the lower part appears blue. This is because the top half is exposed to direct sunlight, while the lower part is not.

APOD: 2025 June 28 Б Lunar Farside
28.06.2025

Tidally locked in synchronous rotation, the Moon always presents its familiar nearside to denizens of planet Earth. From lunar orbit, the Moon's farside can become familiar, though. In fact this sharp picture, a mosaic from the Lunar Reconnaissance Orbiter's wide angle camera, is centered on the lunar farside.

Lunar Farside
9.04.2011

Tidally locked in synchronous rotation, the Moon always presents its familiar nearside to denizens of planet Earth. From lunar orbit, the Moon's farside can become familiar, though. In fact this sharp picture, a mosaic from the Lunar Reconnaissance Orbiter's wide angle camera, is centered on the lunar farside.

Umbra World
14.12.2012

On the morning of November 14, sky gazers from around the world gathered on this little planet to stand in the dark umbral shadow of the Moon. Of course, the Moon cast the shadow...

Milky Way and Planets Near Opposition
21.05.2016

In this early May night skyscape, a mountain road near Bursa, Turkey seems to lead toward bright planets Mars and Saturn and the center of our Milky Way Galaxy, a direction nearly opposite the Sun in planet Earth's sky.

Atlas, Daphnis, and Pan
18.05.2019

Atlas, Daphnis, and Pan are small, inner, ring moons of Saturn. They are shown at the same scale in this montage of images by the Cassini spacecraft that made its grand final orbit of the ringed planet in September 2017. In fact, Daphnis was discovered in Cassini images from 2005.

Seeing Titan
20.08.2020

Shrouded in a thick atmosphere, Saturn's largest moon Titan really is hard to see. Small particles suspended in the upper atmosphere cause an almost impenetrable haze, strongly scattering light at visible wavelengths and hiding Titan's surface features from prying eyes.

NGC 6559: East of the Lagoon
7.10.2021

Slide your telescope just east of the Lagoon Nebula to find this alluring field of view in the rich starfields of the constellation Sagittarius toward the central Milky Way. Of course the Lagoon nebula is also known as M8, the eighth object listed in Charles Messier's famous catalog of bright nebulae and star clusters.

Mercurys Transit: An Unusual Spot on the Sun
14.11.2006

What's that dot on the Sun? If you look closely, it is almost perfectly round. The dot is the result of an unusual type of solar eclipse that occurred last week. Usually it is the Earth's Moon that eclipses the Sun.