Unusual Silica Rich Soil Discovered on Mars
17.12.2007

You're rolling across Mars when you unexpectedly uncover some unusually light soil. You stop. You turn. You return to inspect the soil and find out it is almost purely silica -- the main ingredient in quartz and glass. Such soil has never been found on Mars before. What created this soil?

Aurorae on Jupiter
10.07.2016

Jupiter has aurorae. Like Earth, the magnetic field of the gas giant funnels charged particles released from the Sun onto the poles. As these particles strike the atmosphere, electrons are temporarily knocked away from existing gas molecules. Electric force attracts these electrons back. As the electrons recombine to remake neutral molecules, auroral light is emitted.

Solar System Ball Drop
24.08.2021

Does a ball drop faster on Earth, Jupiter, or Uranus? The featured animation shows a ball dropping from one kilometer high toward the surfaces of famous solar system bodies, assuming no air resistance. The force of gravity depends on the mass of the attracting object, with higher masses pulling down with greater forces.

APOD: 2023 August 8 Б Moon Meets Jupiter
7.08.2023

What's that below the Moon? Jupiter -- and its largest moons. Many skygazers across planet Earth enjoyed the close conjunction of Earth's Moon passing nearly in front of Jupiter in mid-June. The featured image is a single exposure of the event taken from MorцЁn de la Frontera, Spain.

APOD: 2026 April 24 Б Young Moon and Sister Stars
23.04.2026

Sunlit arms of a crescent moon seem to embrace the faint lunar night side in this dramatic celestial scene from planet Earth. The single telephoto exposure tracking the sky was captured on the night of April 19, when a two day old Moon was near perigee in its elliptical orbit.

All of Mars
26.06.2001

From pole to pole, from east to west, this is all of Mars. The above picture was digitally reconstructed from over 200 million laser altimeter measurements taken by the Mars Global Surveyor spacecraft currently orbiting Mars.

Smooth Sections on Asteroid Itokawa
22.04.2007

Why are parts of this asteroid's surface so smooth? No one is yet sure, but it may have to do with the dynamics of an asteroid that is a loose pile of rubble rather than a solid rock.

The Clipper and the Comet
16.10.2024

NASA's Europa Clipper is now headed toward an ocean world beyond Earth. The large spacecraft is tucked into the payload fairing atop the Falcon Heavy rocket in this photo, taken at Kennedy Space Center the day before the mission's successful October 14 launch.

Highlights of the Winter Sky
11.12.2017

What's up in the sky this winter? The featured graphic gives a few highlights for Earth's northern hemisphere. Viewed as a clock face centered at the bottom, early winter sky events fan out toward the left, while late winter events are projected toward the right.

Unusual Aurora During Solar Wind Dropout
22.12.1999

On May 10, for some unknown reason, the Solar Wind virtually stopped. Normally our Sun emits a wind of between five and ten energetic particles per cubic centimeter moving outward at about 500 kilometers per second.