The Backyard Universe
14.04.1999

How far can you see from your own backyard? Across the Solar System, even across our Galaxy, these sights are not difficult. Recently, however, amateur Paul Boltwood gazed across the universe. His record setting image is shown above in false color.

Weak Lensing Distorts the Universe
15.03.2000

Is the distant universe really what it appears to be? Astronomers hope not. Intervening dark matter, which is normally invisible, might show its presence by distorting images originating in the distant universe, much the way an old window distorts images originating on the other side.

APOD: 2007 February 20- White Ridges on Mars
20.02.2007

What created these white ridges on Mars? The images showing the white ridges, including some of the highest resolution images ever taken from Martian orbit, were recorded last year by the Mars Reconnaissance Orbiter (MRO).

J1502 1115: A Triple Black Hole Galaxy
7.07.2014

Most galaxies contain one supermassive black hole -- why does this galaxy have three? The likely reason is that galaxy J1502+1115 is the product of the recent coalescence of three smaller galaxies.

M27: The Dumbbell Nebula
14.09.2014

The first hint of what will become of our Sun was discovered inadvertently in 1764. At that time, Charles Messier was compiling a list of diffuse objects not to be confused with comets.

Charon and the Small Moons of Pluto
26.10.2015

What do the moons of Pluto look like? Before a decade ago, only the largest moon Charon was known, but never imaged. As the robotic New Horizons spacecraft was prepared and launched, other moons were identified on Hubble images but remained only specks of light.

APOD: 2024 December 31 Б The Twisted Disk of NGC 4753
31.12.2024

What do you think this is? HereБs a clue: it's bigger than a bread box. Much bigger. The answer is that pictured NGC 4753 is a twisted disk galaxy, where unusual dark dust filaments provide clues about its history.

APOD: 2025 January 20 Б Comet ATLAS Rounds the Sun
20.01.2025

Why does Comet ATLAS have such colorful tails? Last week Comet C/2024 G3 (ATLAS) passed its closest to the Sun -- well inside the orbit of Mercury -- and brightened dramatically. Unfortunately, the comet was then so angularly near the Sun that it was very hard for humans to see. But NASA's SOHO spacecraft saw it.

Watch the Sky Rotate
10.01.2001

If you could watch the sky for an entire night, what would you see? The above time-lapse sequence from the CONtinuous CAMera (CONCAM) project shows the answer for the skies above Kitt Peak National Observatory on 2000 December 23.

The Orion Nebula from VLT
30.01.2001

The Great Nebula in Orion is a colorful place. Visible to the unaided eye, it appears as a small fuzzy patch in the constellation of Orion. But this image, a representative-color composite...