Retrograde Mars
13.06.2010

Why would Mars appear to move backwards? Most of the time, the apparent motion of Mars in Earth's sky is in one direction, slow but steady in front of the far distant stars. About every two years, however, the Earth passes Mars as they orbit around the Sun.

A Live View from the International Space Station
14.05.2014

If were floating above the Earth right now, this is what you might see. Two weeks ago, the robotic SpaceX Dragon capsule that delivered supplies to the Earth-orbiting International Space Station (ISS) also delivered High Definition Earth Viewing (HDEV) cameras that take and transmit live views of Earth.

NanoSail D2
2.01.2026

In 2011, on January 20, NASA's NanoSail-D2 unfurled a very thin and very reflective 10 square meter sail becoming the first solar sail spacecraft in low Earth orbit. Often considered the stuff...

A Year of Assessing Astronomical Hazards
31.12.2002

Could an asteroid destroy civilization on Earth? Mountain-sized space rocks could potentially impact the Earth causing global effects, and perhaps even be mistaken for a nuclear blast of terrestrial origin. Such large impacts are rare but have happened before. Modern telescopes have therefore begun to scan the skies for signs of approaching celestial hazards.

APOD: 2024 August 13 Б Giant Jet from the International Space Station
13.08.2024

What's that on the horizon? When circling the Earth on the International Space Station early last month, astronaut Matthew Dominick saw an unusual type of lightning just beyond the Earth's edge: a gigantic jet. The powerful jet appears on the left of the featured image in red and blue.

If You Could Stand on Mars
7.02.1996

If you could stand on Mars - what would you see? Viking 1 robot landers answered this question in 1976 with pictures like the one shown above. The dark rocks, red soil, and green-tinged sky grace this rendition of a normal Martian afternoon. At the bottom corners of the picture are portions of Viking spacecraft.

The Largest Impact Crater
6.09.1996

What is the largest known impact crater in the Solar System? Over 1300 miles across, the South Pole-Aitken Basin on the farside of Earth's Moon holds that distinction. Circled above in a false color mosaic of Clementine images it was caused when an asteroid or comet sized object crashed

Lunar Transit from STEREO
3.03.2007

A million miles from planet Earth, last weekend the STEREO B spacecraft found itself in the shadow of the Moon. So, looking toward the Sun, extreme ultraviolet cameras onboard STEREO B were able to record a stunning movie of a lunar transit (aka solar eclipse), as the Moon tracked across the solar disk.

Crescents of Venus
26.08.2023

Just as the Moon goes through phases, Venus' visible sunlit hemisphere waxes and wanes. This sequence of telescopic images illustrates the steady changes for Venus during its recent 2023 apparition as our evening star. Gliding along its interior orbit between Earth and Sun, Venus grows larger during that period because it is approaching planet Earth.

Galaxies in Space
8.03.2025

The plane of our Milky Way galaxy extends beyond the limb of planet Earth in this space age exposure captured by astronaut Don Pettit. His camera, with low light and long duration settings, was pointed out the window of a Dragon crew spacecraft docked with the International Space Station on January 29.