Tropic of Cancer
2.08.2013

This intriguing monument can be found in Taiwan between the cities of Hualian and Taitong. Split into two sides, it straddles a special circle of latitude on planet Earth, near 23.5 degrees north, known as the Tropic of Cancer.

Halo of the Cats Eye
1.06.2014

The Cat's Eye Nebula (NGC 6543) is one of the best known planetary nebulae in the sky. Its haunting symmetries are seen in the very central region of this stunning false-color picture, processed...

NGC 3293: A Bright Young Star Cluster
5.04.2015

Hot blue stars shine brightly in this beautiful, recently formed galactic or "open" star cluster. Open cluster NGC 3293 is located in the constellation Carina, lies at a distance of about 8000 light years, and has a particularly high abundance of these young bright stars.

The Orion Nebula in Infrared from WISE
1.01.2019

The Great Nebula in Orion is an intriguing place. Visible to the unaided eye, it appears as a small fuzzy patch in the constellation of Orion. But this image, an illusory-color four-panel mosaic taken...

Halo of the Cats Eye
6.06.2020

The Cat's Eye Nebula (NGC 6543) is one of the best known planetary nebulae in the sky. Its haunting symmetries are seen in the very central region of this stunning false-color picture, processed...

The Edge of Space
23.07.2021

Where does space begin? For purposes of spaceflight some would say at the Karman line, currently defined as an altitude of 100 kilometers (60 miles). Others might place a line 80 kilometers (50 miles) above Earth's mean sea level.

APOD: 2025 September 9 Б Up from the Earth: Gigantic Jet Lightning
8.09.2025

What's that rising up from the Earth? When circling the Earth on the International Space Station early in July, astronaut Nicole Ayers saw an unusual type of lightning rising up from the Earth: a gigantic jet. The powerful jet appears near the center of the featured image in red, white, and blue.

Planetary Nebula Mz3: The Ant Nebula
4.02.2001

Why isn't this ant a big sphere? Planetary nebula Mz3 is being cast off by a star similar to our Sun that is, surely, round. Why then would the gas that is streaming away create an ant-shaped nebula that is distinctly not round?

Jagged Hills on Jupiters Callisto
28.08.2001

Why does Jupiter's moon Callisto have unusual jagged hills? This mystery came to light after the robot spacecraft Galileo, in orbit around Jupiter since 1995, swooped past the dark moon in May. The resulting pictures were the highest resolution yet obtained for a Jovian moon: objects as small as 3 meters across are discernable.

The Clouds of Jupiter
20.09.1997

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...