A Green Flash from the Sun
3.01.2011

Many think it is just a myth. Others think it is true but its cause isn't known. Adventurers pride themselves on having seen it. It's a green flash from the Sun. The truth is the green flash does exist and its cause is well understood.

Solstice: Sunrises Around the Year
20.12.2020

Does the Sun always rise in the same direction? No. As the months change, the direction toward the rising Sun changes, too. The featured image shows the direction of sunrise every month during 2019 as seen from near the city of Amman, Jordan.

Milky Way Auroral Flower
17.10.2022

Could the stem of our Milky Way bloom into an auroral flower? No, not really, even though it may appear that way in todayБs featured all-sky image. On the left, the central plane of our home galaxy extends from the horizon past the middle of the sky.

Solar Eclipse from a Ship
28.04.2023

Along a narrow path that mostly avoided landfall, the shadow of the New Moon raced across planet Earth's southern hemisphere on April 20 to create a rare annular-total or hybrid solar eclipse. From...

Rigel and the Witch Head Nebula
14.01.2018

By starlight this eerie visage shines in the dark, a crooked profile evoking its popular name, the Witch Head Nebula. In fact, this entrancing telescopic portrait gives the impression that the witch has fixed her gaze on Orion's bright supergiant star Rigel.

Iron in the Butterfly Nebula
20.07.2020

Can stars, like caterpillars, transform themselves into butterflies? No, but in the case of the Butterfly Nebula -- it sure looks like it. Though its wingspan covers over 3 light-years and its estimated surface temperature...

Jupiter's Colorful Clouds
3.08.1996

What makes the colors in Jupiter's clouds? With a mean temperature of 120 degrees Kelvin (-153 degrees Celsius) and a composition dominated by Hydrogen (about 90%), and Helium (about 10%) with a smattering...

Saturnian Aurora
8.01.1998

Girdling the second largest planet in the Solar System, Saturn's Rings are one of the most spectacular sights for earthbound telescopes. This recently released image, from the orbiting Hubble Space Telescope's STIS instrument, offers a striking view of another kind of ring around Saturn - pole encircling rings of ultraviolet aurora.

Light Deposits Indicate Water Flowing on Mars
11.12.2006

What's creating light-toned deposits on Mars? Quite possibly -- water! Images of the same parts of mid-latitude Mars taken over the years but released only last week have shown unexpected new light-toned deposits where there were none before.

Earthgrazer: The Great Daylight Fireball of 1972
1.03.2009

What is that streaking across the sky? A bright earthgrazing meteor. In 1972, an unusually bright meteor from space was witnessed bouncing off Earth's atmosphere, much like a skipping stone can bounce off of a calm lake.