Arches Across an Arctic Sky
13.01.2021

What are these two giant arches across the sky? Perhaps the more familiar one, on the left, is the central band of our Milky Way Galaxy. This grand disk of stars and nebulas here appears to encircle much of the southern sky.

1999 Leonid Fireball
2.12.1999

Most Leonid meteoroids, the bits of comet debris which produce the annual Leonid meteor shower, range from a mere millimeter to a centimeter in diameter. Yet these cosmic grains of sand and gravel can put on quite a spectacular show. How can something so small generate so much light?

Aurora Through a Moonlit Sky
2.11.1999

A night sky can glow in fascinating ways. Through a clearing in the woods, the pictured sky above Alaska shines by reflected light from a nearby city, by the brightness of the Moon, and by aurora.

Aurora Over Norway
20.09.2010

Auroras can make spectacular sights. Photographed above last weekend, flowing multi-colored auroras helped illuminate a busy sky above TromsЬ, Norway. Besides the spectacular aurora pictured above, the photographer caught three satellites streaks, one airplane streak, and a friend trying to capture the same sight.

APOD: 2024 December 29 Б Methane Bubbles Frozen in Lake Baikal
29.12.2024

What are these bubbles frozen into Lake Baikal? Methane. Lake Baikal, a UNESCO World Heritage Site in Russia, is the world's largest (by volume), oldest, and deepest lake, containing over 20% of the world's fresh water.

Aurora over Sweden
3.05.2016

It was bright and green and stretched across the sky. This striking aurora display was captured last month just outside of жstersund, Sweden. Six photographic fields were merged to create the featured panorama spanning almost 180 degrees. Particularly striking aspects of this aurora include its sweeping arc-like shape and its stark definition.

Lunar Eclipse over Rio
30.07.2018

Moonrise doesn't usually look this interesting. For one thing, the full moon is not usually this dark -- but last Friday the moon rose here as it simultaneously passed through the shadow of the Earth.

APOD: 2024 August 11 Б Animation: Perseid Meteor Shower
11.08.2024

Where do Perseid meteors come from? Mostly small bits of stony grit, Perseid meteoroids were once expelled from Comet Swift-Tuttle and continue to follow this comet's orbit as they slowly disperse. The featured animation depicts the entire meteoroid stream as it orbits our Sun.

Halo and Hexagons
9.11.2006

As a bright November Moon lit up the night sky last week, Gil Esquerdo spotted this lovely Moon halo overhead at the Whipple Observatory on Mt. Hopkins, Arizona. In the foreground, the structure...

Omega Sunrise
21.09.2020

Capturing this sunrise required both luck and timing. First and foremost, precise timing was needed to capture a sailboat crossing right in front of a rising Sun. Additionally, by a lucky coincidence, the background Sun itself appears unusual -- it looks like the Greek letter Omega (н).