Global Warming Predictions
21.04.2009

How much will the Earth's surface warm up over the lives of our children? No one is sure. Compared to the past 100 million years, the Earth is currently enduring a relative cold spell, possibly about four degrees Celsius below average.

Centaurus Galaxy Cluster in X Rays
28.03.2002

The Centaurus Cluster is a swarm of hundreds of galaxies a mere 170 million light-years away. Like other immense galaxy clusters, the Centaurus Cluster is filled with gas at temperatures of 10 million degrees or more, making the cluster a luminous source of cosmic x-rays.

The Blue Snowball Planetary Nebula
21.11.1996

Will the Sun one day look like - a blue snowball? Maybe! The Blue Snowball is a planetary nebula - and in 5 billion years the Sun will throw off its outer layers and go through a planetary nebula phase.

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...

THEMIS of Mars
2.11.2001

Not an ancient Greek goddess, THEMIS is modern acronese for THermal EMission Imaging System. Above is this remarkable instrument's premier infrared image of Mars, from the newly orbiting Mars Odyssey spacecraft. Taken...

M55 Color Magnitude Diagram
23.02.2001

This color "picture" of globular star cluster M55 may not look like any star cluster you've ever seen. Still, it shows a most fundamental view for students of stellar astronomy. In the picture...

APOD: 2023 December 20 Б Ice Halos over Bavaria
20.12.2023

What's causing those unusual sky arcs? Ice crystals. While crossing a field of fresh snow near Fцssen, Bavaria, Germany, earlier this month, the photographer noticed that he had entered an ice fog.

Planck Maps the Microwave Background
25.03.2013

What is our universe made of? To help find out, ESA launched the Planck satellite to map, in unprecedented detail, slight temperature differences on the oldest surface known -- the background sky left billions of years ago when our universe first became transparent to light.

Launch of the Parker Solar Probe
15.08.2018

When is the best time to launch a probe to the Sun? The now historic answer -- which is not a joke because this really happened this past weekend -- was at night. Night, not only...

X-Rays from the Galactic Plane
14.08.2001

In February 2000, the orbiting Chandra X-ray Observatory spent 27 hours staring into the plane of our Milky Way galaxy. Its target was a spot in the small constellation Scutum, within the Milky Way's zone of avoidance where galactic gas and dust clouds block visible light, making a poor window for optical telescopes.