ISS and Mercury Too
13.05.2016

Transits of Mercury are relatively rare. Monday's leisurely 7.5 hour long event was only the 2nd of 14 Mercury transits in the 21st century. If you're willing to travel, transits of the International Space Station can be more frequent though, and much quicker.

Halley Dust and Milky Way
10.05.2019

Grains of cosmic dust streaked through the mostly moonless night skies of May 7. Swept up as planet Earth plowed through the debris streams left behind by periodic Comet Halley, the annual meteor shower is known as the Eta Aquarids.

Biking to the Moon
2.10.2020

As you watched October's first Full Moon rise last night, the Full Moon closest to the northern autumnal equinox, you were probably asking yourself, "How long would it take to bike...

The Last Days of Venus as the Evening Star
6.01.2022

That's not a young crescent Moon posing behind cathedral towers after sunset. It's Venus in a crescent phase. About 40 million kilometers away and about 2 percent illuminated by sunlight...

NGC 6302: The Butterfly Nebula
6.06.2025

The bright clusters and nebulae of planet Earth's night sky are often given the names of flowers or insects, and its whopping 3 light-year wingspan, NGC 6302 is no exception. With an estimated...

Eros Horizon View
25.05.2000

Since April 30, the robotic NEAR-Shoemaker spacecraft has been orbiting only 31 miles from asteroid Eros. Cruising over the asteroid's north and south poles at a leisurely 7 miles per hour, the spacecraft completes an orbit once every 1.2 earth days. This dramatic horizon view

Moon Over Andromeda
28.12.2006

The Great Spiral Galaxy in Andromeda (aka M31), a mere 2.5 million light-years distant, is the closest large spiral to our own Milky Way. Andromeda is visible to the unaided eye as a small...

3D Barringer Meteorite Crater
23.06.2007

Baringer Meteorite Crater, near Winslow, Arizona, is one of the best known impact craters on planet Earth. View this color stereo anaglyph with red/blue glasses to get a dramatic sense of the crater's dimensions -- one mile wide, and up to 570 feet deep.

A Busy Space Walk at the Space Station
18.07.2011

What's that astronaut doing? Unloading a space shuttle -- for the last time. After the space shuttle Atlantis docked with the Mike Fossum underwent a long spacewalk that included carrying a Robotics Refueling Mission (RRM) payload from Atlantis' cargo bay to a platform used by the space station's famous robot DEXTRE.

Bright Spiral Galaxy M81
18.11.2014

One of the brightest galaxies in planet Earth's sky is similar in size to our Milky Way Galaxy: big, beautiful M81. This grand spiral galaxy can be found toward the northern constellation of the Great Bear (Ursa Major).