A Day in the Life of a Human Sundial
11.08.2017

Have you ever wanted to be a gnomon? Of course, a gnomon is the tall part of a sundial that casts a shadow. The gnomon's shadow moves as the Sun moves across the sky, indicating time by the shadow's position on the dial face.

Pastel Planet, Triple Eclipse
10.11.2004

This false-color image of banded gas giant Jupiter shows a triple eclipse in progress on March 28 - a relatively rare event, even for a large planet with many moons. Captured by the Hubble Space...

Wisps Surrounding the Horsehead Nebula
20.02.2006

The famous Horsehead Nebula in Orion is not alone. A deep exposure shows that the dark familiar shaped indentation, visible just below center, is part of a vast complex of absorbing dust and glowing gas.

Wisps Surrounding the Horsehead Nebula
6.04.2008

The famous Horsehead Nebula in Orion is not alone. A deep exposure shows that the dark familiar shaped indentation, visible just below center, is part of a vast complex of absorbing dust and glowing gas.

Solar Eclipse in View
7.04.2005

Friday's solar eclipse will be a rare hybrid - briefly appearing as either an annular eclipse or a total eclipse when viewed from along the narrow track of the Moon's shadow. Unfortunately that...

All the Eclipses of 2017
6.12.2017

As seen from planet Earth, all the lunar and solar eclipses of 2017 are represented at the same scale in these four panels. The year's celestial shadow play was followed through four different countries by one adventurous eclipse chaser.

South Pacific Shadowset
23.08.2024

The full Moon and Earth's shadow set together in this island skyscape. The alluring scene was captured Tuesday morning, August 20, from Fiji, South Pacific Ocean, planet Earth. For early morning risers shadowset in the western sky is a daily apparition.

Eclipse under the ISS
26.06.2020

The dark shadow of the New Moon reached out and touched planet Earth on June 21. A high definition camera outside the International Space Station captured its passing in this snapshot from low Earth orbit near the border of Kazakhstan and China.

Vintage Gamma Rays
6.04.2002

Gamma-rays are the most energetic form of electromagnetic radiation. But these high energy photons penetrate and interact in normal materials and cannot be focused by lenses and mirrors like those in optical telescopes. So how do you make an image in gamma-ray light?

Tololo Totality
14.03.2025

On March 14 the Moon was Full. In an appropriate celebration of Pi day, that put the Moon 3.14 radians (180 degrees) in ecliptic longitude from the Sun in planet Earth's sky.