ISS Transits Mars
23.09.2020

Yes, but have you ever seen the space station do this? If you know when and where to look, watching the bright International Space Station (ISS) drift across your night sky is a fascinating sight -- but not very unusual.

APOD: 2023 February 28 Б Crescent Moon Beyond Greek Temple
28.02.2023

Why is a thin crescent moon never seen far from a horizon? Because the only geometry that gives a thin crescent lunar phase occurs when the Moon appears close to the Sun in the sky.

A Cosmic Triangle
15.04.2020

It was an astronomical triple play. Setting on the left, just after sunset near the end of last month, was our Moon -- showing a bright crescent phase. Setting on the right was Venus, the brightest planet in the evening sky last month -- and this month, too.

The Traffic in Taurus
3.04.2020

There's a traffic jam in Taurus lately. On April 1, this celestial frame from slightly hazy skies over Tapiobicske, Hungary recorded an impressive pile up toward the zodiacal constellation of the Bull and the Solar System's ecliptic plane.

Moon over ISS
6.11.2020

Completing one orbit of our fair planet in 90 minutes the International Space Station can easily be spotted by eye as a very bright star moving through the night sky. Have you seen it? The next time you do, you will have recognized the location of over 20 years of continuous human presence in space.

A Moon Dressed Like Saturn
16.03.2020

Why does Saturn appear so big? It doesn't -- what is pictured are foreground clouds on Earth crossing in front of the Moon. The Moon shows a slight crescent phase with most of its surface visible by reflected Earthlight known as ashen glow.

Analemma of the Moon
7.05.2020

An analemma is that figure-8 curve you get when you mark the position of the Sun at the same time each day for one year. But the trick to imaging an analemma of the Moon is to wait bit longer.

Moon Pairs and the Synodic Month
26.09.2020

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.

Moon Phases in 2021
11.01.2021

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.

Moon in Inverted Colors
8.03.2022

Which moon is this? It's Earth's moon -- but in inverted colors. Here, the pixel values corresponding to light and dark areas have been translated in reverse, or inverted, producing a false-color representation reminiscent of a black and white photographic negative.