Follow a sunset on a clear day against a distant horizon and you might glimpse green just as the Sun disappears from view. The green flash is caused by refraction […]

That’s not a bright star and crescent Moon caught between branches of a eucalyptus tree. It’s Venus in a crescent phase and Mercury. Near the western horizon after sunset, the […]

Still bathed in sunlight, the International Space Station arced through the evening sky over lake Wulfsahl-Gusborn in northern Germany, just after sunset on March 25. The familiar constellation of Orion […]

What are those dots between Saturn’s rings? Our Earth and Moon. Just over three years ago, because the Sun was temporarily blocked by the body of Saturn, the robotic Cassini […]

What’s higher than the Himalayas? Although the Himalayan Mountains are the tallest on planet Earth, they don’t measure up to the Milky Way. Visible above the snow-capped mountains in the […]

Inside the head of this interstellar monster is a star that is slowly destroying it. The huge monster, actually an inanimate series of pillars of gas and dust, measures light […]

The largest canyon in the Solar System cuts a wide swath across the face of Mars. Named Valles Marineris, the grand valley extends over 3,000 kilometers long, spans as much […]

Stars shine and satellites glint in this clear, dark, night sky over Wannon Falls Reserve, South West Victoria, Australia. In fact the fuzzy, faint apparition above the tree tops is […]

With natal dust clouds in silhouette against glowing atomic gas, this colorful and chaotic vista lies within one of the largest star forming regions in the Milky Way galaxy, the […]

Just as the Moon goes through phases, Venus’ visible sunlit hemisphere waxes and wanes. This composite of backyard telescopic images illustrates the steady changes for Venus during its current stint […]