Venus Just After Sunset
1.02.2006

Is that Venus or an airplane? A common ponderable for sky enthusiasts is deciding if that bright spot near the horizon is the planet Venus. Usually, an airplane will show itself by moving significantly in a few moments. Venus will set only slowly as the Earth turns.

In the Center of Spiral Galaxy M61
20.05.2014

M61 is a barred spiral galaxy located in the nearby Virgo Cluster of Galaxies. Visible in M61 are a host of features common to spiral galaxies: bright spiral arms, a central bar, dust lanes, and bright knots of stars. M61, also known as NGC 4303, in similar to our own Milky Way Galaxy.

Pluto s Snakeskin Terrain
25.09.2015

A mountainous region informally known as Tartarus Dorsa sprawls some 530 kilometers (330 miles) across this Plutonian landscape. Recently downloaded from New Horizons, it combines blue, red, and infrared image data in an extended color view captured near the spacecraft's close approach to Pluto on July 14.

Jupiter and Venus from Earth
25.10.2015

It was visible around the world. The sunset conjunction of Jupiter and Venus in 2012 was visible almost no matter where you lived on Earth. Anyone on the planet with a clear western horizon at sunset could see them.

Milky Way over Yellowstone
29.01.2020

The Milky Way was not created by an evaporating lake. The pool of vivid blue water, about 10 meters across, is known as Silex Spring and is located in Yellowstone National Park in Wyoming, USA. Steam rises off the spring, heated by a magma chamber deep underneath known as the Yellowstone hotspot.

Direct Projection: The Moon in My Hands
28.02.2022

You don't have to look through a telescope to know where it's pointing. Allowing the telescope to project its image onto a large surface can be useful because it dilutes the intense brightness of very bright sources. Such dilution is useful for looking at the Sun, for example during a solar eclipse.

APOD: 2023 April 3 Б The Galactic Center Radio Arc
3.04.2023

What causes this unusual curving structure near the center of our Galaxy? The long parallel rays slanting across the top of the featured radio image are known collectively as the Galactic Center Radio Arc and point out from the Galactic plane.

Orbiting a Black Hole
1.07.2013

What would it look like to orbit a black hole? Since the strong gravity of the black hole can significantly alter light paths, conditions would indeed look strange. For one thing, the entire sky would be visible, since even stars behind the black hole would have their light bent to the observer's eye.

Cassini Approaches Saturn
19.04.2020

What would it look like to approach Saturn in a spaceship? One doesn't have to just imagine -- the Cassini spacecraft did just this in 2004, recording thousands of images along the way, and hundreds of thousands more since entering orbit.

The Southern Cliff in the Lagoon
15.05.2021

Undulating bright ridges and dusty clouds cross this close-up of the nearby star forming region M8, also known as the Lagoon Nebula. A sharp, false-color composite of narrow band visible and broad band near-infrared...