Noctilucent Clouds
19.06.2005

Sometimes it's night on the ground but day in the air. As the Earth rotates to eclipse the Sun, sunset rises up from the ground. Therefore, at sunset on the ground, sunlight still shines on clouds above.

Sunset at the Portara
20.03.2009

Today, the Sun crosses the celestial equator heading north at 11:44 UT. Known as an equinox, this astronomical event marks the first day of spring in the northern hemisphere and autumn in the south. It also marks the beginning of Norouz, the Persian (Iranian) new year. Equinox means equal night.

Sunrise Analemma
20.03.2003

Astronomically speaking, at the Equinox on March 21, 01:00 UT (March 20, 8:00 PM ET) the season changes. For this Equinox the Sun rises due east as it crosses the celestial equator heading north. In celebration, consider this spectacular sunrise analemma!

S is for Sun
21.03.2002

Taken yesterday from the SOHO spacecraft, this false-color image shows the active Sun near the March Equinox, the beginning of Fall in the south and Spring in the northern hemisphere. Recorded in a band...

A Sharper View of a Tilted Planet
18.11.2004

These sharp views of tilted gas giant Uranus show dramatic details of the planet's atmosphere and ring system. The remarkable ground-based images were made using a near-infrared camera and the Keck Adaptive Optics system to reduce the blurring effects of Earth's atmosphere.