APOD: 2023 January 17 Б Unexpected Clouds Toward the Andromeda Galaxy
17.01.2023

Why are there oxygen-emitting arcs near the direction of the Andromeda galaxy? No one is sure. The gas arcs, shown in blue, were discovered and first confirmed by amateur astronomers just last year.

Quarter Moons
21.10.2023

Half way between New Moon and Full Moon is the Moon's first quarter phase. That's a quarter of the way around its moonthly orbit. At the first quarter phase, half the Moon's visible side is illuminated by sunlight.

APOD: 2024 June 12 Б Aurora over Karkonosze Mountains
12.06.2024

It was the first time ever. At least, the first time this photographer had ever seen aurora from his home mountains. And what a spectacular aurora it was. The Karkonosze Mountains in Poland are usually too far south to see any auroras.

APOD: 2024 June 18 Б Gigantic Jets over Himalayan Mountains
18.06.2024

Yes, but can your thunderstorm do this? Pictured here are gigantic jets shooting up from a thunderstorm last week toward the Himalayan Mountains in China and Bhutan. The composite image captured four long jets that occurred only minutes apart.

APOD: 2025 July 8 Б The Pleiades in Red and Blue
8.07.2025

If you have looked at the sky and seen a group of stars about the size of the full Moon, that's the Pleiades (M45). Perhaps the most famous star cluster in the sky, its brightest stars can be seen even from the light-polluted cities.

APOD: 2025 December 15 Б Gemini Meteors over Snow Capped Mountains
15.12.2025

Where are all of these meteors coming from? In terms of direction on the sky, the pointed answer is the constellation of Gemini. That is why the major meteor shower in December is known as the Geminids -- because shower meteors all appear to come from a radiant toward Gemini.

APOD: 2026 April 21 Б Three Sky Arches over Snowy Alps
21.04.2026

Why are there three arches across the sky instead of two? Last month, after being dropped off by a helicopter at a high mountain peak in the Alps near the Swiss Italian border, an adventurous astrophotographer expected two arches of our Milky Way galaxy to be visible during the night.

Centaurus A: The Galaxy Deep Inside
2.02.2002

Deep inside Centaurus A, the closest active galaxy to Earth, lies ... another galaxy! Cen A is a giant elliptical galaxy a mere 10 million light-years distant with a central jumble of stars, dust, and gas that probably hides a massive black hole.

Hyakutake, Venus, Orion, and Pond
18.04.1996

Can you find Comet Hyakutake in the above picture? In this gorgeous photo, the starry night sky of April 9th is pictured with its new comet visitor. In the foreground is a pond with the lights of Kansas City, Missouri on the western horizon. On the upper left, the constellation of Orion is visible.

The Satellites that Surround Earth
14.07.2003

Thousands of satellites orbit the Earth. Costing billions of dollars, this swarm of high altitude robots is now vital to communication, orientation, and imaging both Earth and space. One common type of orbit is geostationary where a satellite will appear to hover above one point on Earth's equator.