Explorer I
12.02.1998

Inaugurating the era of space exploration for the US, the First Explorer was launched into Earth orbit forty years ago (February 1, 1958) by the Army Ballistic Missle Agency. The Explorer I satellite weighed...

Lightning on Earth
18.08.2004

Nobody knows what causes lightning. It is known that charges slowly separate in some clouds causing rapid electrical discharges (lightning), but how electrical charges get separated in clouds remains a topic of much research.

A Prominence on the Sun
18.09.2015

This eerie landscape of incandescent plasma suspended in looping and twisted magnetic fields stretched toward the Sun's eastern horizon on September 16. Captured through a backyard telescope and narrowband filter in light from ionized hydrogen, the scene reveals a gigantic prominence lofted above the solar limb.

Cirrus over Paris
21.06.2016

What's that over Paris? Cirrus. Typically, cirrus clouds appear white or gray when reflecting sunlight, can appear dark at sunset (or sunrise) against a better lit sky. Cirrus are among the highest types of clouds and are usually thin enough to see stars through.

A Halo Around the Moon
6.12.2008

Have you ever seen a halo around the Moon? This fairly common sight occurs when high thin clouds containing millions of tiny ice crystals cover much of the sky. Each ice crystal acts like a miniature lens.

Milky Way and Zodiacal Light over Australian Pinnacles
22.10.2022

What strange world is this? Earth. In the foreground of the featured image are the Pinnacles, unusual rock spires in Nambung National Park in Western Australia. Made of ancient sea shells (limestone), how these human-sized picturesque spires formed remains a topic of research. The picturesque panorama was taken in 2017 September.

All Sky Moon Shadow
26.04.2024

If the Sun is up but the sky is dark and the horizon is bright all around, you might be standing in the Moon's shadow during a total eclipse of the Sun. In fact, the all-sky Moon shadow shown in this composited panoramic view was captured from a farm near Shirley, Arkansas, planet Earth.

Light at the End of the Road
31.08.2016

The bright light at the end of this country road is actually a remarkably close conjunction of two planets. After sunset on August 27 brilliant Venus and Jupiter almost appear as a single celestial beacon in the night skyscape taken near Lake Wivenhoe, Queensland, Australia.

24 Million Kilometers to Saturn
31.05.2004

Next stop: Saturn. The Cassini-Huygens spacecraft is approaching Saturn and will fire its engines to break into orbit around the ringed giant on July 1. The robot spacecraft was launched in 1997 and rounded Jupiter in 2001.

Galileo Demonstrates the Telescope
14.10.2001

Galileo Galilei made a good discovery great. Upon hearing at age 40 that a Dutch optician had invented a glass that made distant objects appear larger, Galileo crafted his own telescope and turned it toward the sky.