Lunar Eclipses
25.04.2013

The dark, inner shadow of planet Earth is called the umbra. Shaped like a cone extending into space, it has a circular cross section and is most easily seen during a lunar eclipse. But the complete cross section is larger than the Moon's angular size in the stages of an eclipse.

NGC 1316: After Galaxies Collide
2.02.2017

An example of violence on a cosmic scale, enormous elliptical galaxy NGC 1316 lies about 75 million light-years away toward Fornax, the southern constellation of the Furnace. Investigating the startling sight, astronomers suspect the giant galaxy of colliding with smaller neighbor NGC 1317 seen just above, causing far flung loops and shells of stars.

The Tulip and Cygnus X 1
29.07.2021

This tall telescopic field of view looks out along the plane of our Milky Way Galaxy toward the nebula rich constellation Cygnus the Swan. Popularly called the Tulip Nebula, the brightest glowing cloud of interstellar gas and dust above center is also found in the 1959 catalog by astronomer Stewart Sharpless as Sh2-101.

A Beautiful Trifid
5.08.2022

The beautiful Trifid Nebula is a cosmic study in contrasts. Also known as M20, it lies about 5,000 light-years away toward the nebula rich constellation Sagittarius. A star forming region in the plane...

Gullies on Mars
24.10.2002

The Gullies of Mars would probably not have been sensational enough for the title of a vintage Edgar Rice Burroughs story about the Red Planet. But it would get the attention of planetary scientists today.

SN 1006: Pieces of the Cosmic Ray Puzzle
16.10.1996

Research balloon flights conducted in 1912 by Austrian physicist Victor Hess revealed that the Earth was constantly bombarded by high energy radiation from space - which came to be called "Cosmic Rays". What are Cosmic Rays and where do they come from?

Elliptical Galaxy NGC 1132
13.02.2008

NGC 1132 is one smooth galaxy -- but how did it form? As an elliptical galaxy, NGC 1132 has little dust and gas, and few stars have formed in it recently. Although many elliptical galaxies are in clusters of galaxies, NGC 1132 appears as a large, isolated galaxy toward the constellation of the River (Eridanus).

Solargraphy Analemmas
20.03.2014

Today is the equinox. The Sun crosses the celestial equator heading north at 16:57 UT, marking the northern hemisphere's first day of spring. To celebrate, consider this remarkable image following the Sun's yearly trek through planet Earth's sky, the first analemmas exposed every day through the technique of solargraphy.

Rainbow Airglow over the Azores
22.03.2016

Why would the sky glow like a giant repeating rainbow? Airglow. Now air glows all of the time, but it is usually hard to see. A disturbance however -- like an approaching storm -- may cause noticeable rippling in the Earth's atmosphere.

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.