HET: The New Largest Optical Telescope
27.12.1996

Most of our universe is too dim to see. To peer into our cosmos' unknown depths, astronomers must deploy new tools - and the classic new tool is a larger telescope. Pictured above is the new Hobby-Eberly Telescope (HET) which recently declared "first light" in western Texas.

SuitSat1: A Spacesuit Floats Free
27.04.2014

A spacesuit floated away from the International Space Station eight years ago, but no investigation was conducted. Everyone knew that it pushed by the space station crew. Dubbed Suitsat-1, the unneeded Russian Orlan spacesuit filled mostly with old clothes was fitted with a faint radio transmitter and released to orbit the Earth.

Sundogs over the VLA
23.08.1999

What if you woke up one morning and saw more than one Sun in the sky? Most probably, you would be seeing sundogs, extra-images of the Sun created by falling ice-crystals in the Earth's atmosphere. As water freezes in the atmosphere, small, flat, six-sided, ice crystals might be formed.

SuitSat 1: A Spacesuit Floats Free
28.03.2021

A spacesuit floated away from the International Space Station 15 years ago, but no investigation was conducted. Everyone knew that it was pushed by the space station crew. Dubbed Suitsat-1, the unneeded Russian Orlan spacesuit filled mostly with old clothes was fitted with a faint radio transmitter and released to orbit the Earth.

Ultraviolet Earth from an Observatory on the Moon
28.10.2018

Which planet is this? Earth. The featured false color picture shows how the Earth shines in ultraviolet (UV) light. The image is historic because it was taken from the surface of the Moon by humanity's only lunar observatory.

APOD: 2024 August 14 Б Meteors and Aurora over Germany
14.08.2024

This was an unusual night. For one thing, the night sky of August 11 and 12, earlier this week, occurred near the peak of the annual Perseid Meteor Shower. Therefore, meteors streaked across the dark night as small bits cast off from Comet Swift-Tuttle came crashing into the Earth's atmosphere.

Pantheon Earth and Moon
20.04.2007

Could this be a picture of the Earth and Moon from space? It certainly looks like it at first glance, with a dark, cratered Moon standing off from planet Earth's lovely blue disk surrounded by a nurturing atmosphere. In fact, this view looks up into the dome of the ancient Pantheon in Rome.

Asteroids in the Distance
16.03.1998

Rocks from space hit Earth every day. The larger the rock, though, the less often Earth is struck. Many kilograms of space dust pitter to Earth daily. Larger bits appear initially as a bright meteor. Baseball-sized rocks and ice-balls streak through our atmosphere daily, most evaporating quickly to nothing.

Cosmic Rays
14.08.2006

Have you ever been hit by a beam of high energy particles from above? Surely you have -- it happens all of the time. Showers of high energy particles occur when energetic cosmic rays strike the top of the Earth's atmosphere. Cosmic rays were discovered unexpectedly in 1912.

Aurora Over Clouds
2.04.2001

Aurorae usually occur high above the clouds. The auroral glow is created when fast-moving particles ejected from the Sun impact air molecules high in the Earth's atmosphere. An oxygen molecule, for example, will glow in a green light when reacquiring an electron lost during a collision with a solar particle.