The Millennium that Defined Earth
30.12.1999

When the second millennium began, people generally knew that the Earth was round, but few saw much of it beyond their local village. As the millennium progressed, humans mapped the continents, circumnavigated the globe, and determined the composition of the Earth.

An Iridescent Pileus Cloud over China
5.09.2022

Yes, but how many dark clouds have a multicolored lining? Pictured, behind this darker cloud, is a pileus iridescent cloud, a group of water droplets that have a uniformly similar size and so together diffract different colors of sunlight by different amounts. The featured image was taken last month in Pu'er, Yunnan Province, China.

Barred Spiral Galaxy NGC 1365
19.05.1997

Many spiral galaxies have bars across their centers. Even our own Milky Way Galaxy is thought to have a bar, but perhaps not so prominent as the one in NGC 1365, shown above. The persistence and motion of the bar imply relatively massive spiral arms.

White Dwarf Stars Cool
1.11.1997

Diminutive by stellar standards, white dwarf stars are also intensely hot ... but they are cooling. No longer do their interior nuclear fires burn, so they will continue to cool until they fade away. This Hubble Space Telescope image covers a small region near the center of a globular cluster known as M4.

M6: The Butterfly Cluster
5.01.1999

To some, the outline of the open cluster of stars M6 resembles a butterfly. M6, also known as NGC 6405, spans about 20 light-years and lies about 2,000 light years distant.

NGC 1977: Blue Reflection Nebula in Orion
19.03.1996

The Orion Nebula is visible to the unaided eye as a fuzzy patch near the famous belt of three stars in the constellation Orion. The above picture captures a part of the Orion Nebula that primarily reflects light from bright Orion stars.

Apollo 17 Lunarscape: A Magnificent Desolation
20.04.1996

Buzz Aldrin, Apollo 11 Lunar Module pilot and the second human to walk on the Moon described the lunar landscape as "a magnificent desolation". Dramatic pictures from the Apollo missions to the moon's surface testify to this apt turn of phrase.

Median Mashup: Hubble s Top 100
13.09.2014

Now, as you sip your cosmic latte you can view 100 Hubble Space Telescope images at the same time. The popular scenes of the cosmos as captured from low Earth orbit are all combined into this single digital presentation. To make it, Hubble's top 100 images were downloaded and resized to identical pixel dimensions.

Human as Spaceship
14.08.2016

You are a spaceship soaring through the universe. So is your dog. We all carry with us trillions of microorganisms as we go through life. These multitudes of bacteria, fungi, and archaea have different DNA than you. Collectively called your microbiome, your shipmates outnumber your own cells.

Night Hides the World
7.02.2014

Stars come out as evening twilight fades in this serene skyscape following the Persian proverb "Night hides the world, but reveals a universe." In the scene from last November, the Sun is setting over northern Kenya and the night will soon hide the shores of Lake Turkana, home to many Nile crocodiles.