The X-Ray Sky
2.01.1996

What if you could see X-rays? If you could, the night sky would be a strange and unfamiliar place. X-rays are about 1,000 times more energetic than visible light photons and are produced in violent and high temperature astrophysical environments.

Pioneer 10: The First 7 Billion Miles
25.08.2001

Q: What was made by humans and is 7.3 billion miles away? A: Pioneer 10 -- and 1997 was the 25th anniversary of its launch. Almost 11 light-hours distant, Pioneer 10 is presently about twice as far from the Sun as Pluto, and bound for interstellar space at 28,000 miles per hour.

Pioneer 10: The First 6 Billion Miles
20.06.1998

Q: What was made by humans and is 6.5 billion miles away? A: Pioneer 10 - and last year was the 25th anniversary of its launch. More than 9.5 light-hours distant, Pioneer 10 is presently about twice as far from the Sun as Pluto, bound for interstellar space at 28,000 miles per hour.

The Gum Nebula Expanse
24.05.2018

Named for a cosmic cloud hunter, Australian astronomer Colin Stanley Gum (1924-1960), The Gum Nebula is so large and close it is actually hard to see. In fact, we are only about 450 light-years from the front edge and 1,500 light-years from the back edge of this interstellar expanse of glowing hydrogen gas.

Rings Around the Ring Nebula
15.07.2018

There is much more to the familiar Ring Nebula (M57), however, than can be seen through a small telescope. The easily visible central ring is about one light-year across, but this remarkably deep exposure...

3D Homunculus Nebula
17.07.2014

If you're looking for something to print with that new 3D printer, try out a copy of the Homunculus Nebula. The dusty, bipolar cosmic cloud is around 1 light-year across but is slightly scaled down for printing to about 1/4 light-nanosecond or 80 millimeters.

Solar Sail
21.08.2004

Could solar sailing become a future Olympic sport? Nearly 400 years ago astronomer Johannes Kepler observed comet tails blown by a solar breeze and suggested that vessels might likewise navigate through space using appropriately fashioned sails.

Explore Rosettas Comet
3.10.2016

What would it be like to fly around a comet nucleus? To find out, just wait for your WebGL-compatible browser to load a detailed digital model of Comet 67P and then -- go exploring! With...

Sharpest Ultima Thule
28.02.2019

On January 1, New Horizons swooped to within 3,500 kilometers of the Kuiper Belt world known as Ultima Thule. That's about 3 times closer than its July 2015 closest approach to Pluto.

APOD: 2024 July 1 Б Time Spiral
1.07.2024

What's happened since the universe started? The time spiral shown here features a few notable highlights. At the spiral's center is the Big Bang, the place where time, as we know it, began about 13.8 billion years ago.