Comet, Meteor, Nebula, Star
22.12.2004

Several wonders of the late-year northern sky appeared together for a few fleeting moments on December 13. On the bottom left, just above the hill, is blue Sirius, the brightest star in the sky.

Candidates for a Hypernova
20.04.1999

What created these huge explosion remnants? Speculation has been building recently that outbursts even more powerful than well-known supernovae might occur. Dubbed hypernovae, these explosions might result from high-mass stars and liberate perhaps ten times more energy than conventional supernovae.

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.

A Falcon 9 Moon
5.09.2020

Illuminating planet Earth's night, full moons can have many names. This year the last full moon of northern hemisphere summer was on September 2, known to some as the Full Corn Moon.

APOD: 2024 February 28 Б Shades of Night
28.02.2024

How does the sky turn dark at night? In stages, and with different characteristic colors rising from the horizon. The featured image shows, left to right, increasingly late twilight times after sunset in 20 different vertical bands. The picture was taken last month in Syracuse, Sicily, Italy, in the direction opposite the Sun.

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.

Europa Rotating
16.01.2001

Evidence has been mounting that beneath the vast planes of ice that cover Europa lies water -- liquid oceans that might be home to alien life. The smallest of Jupiter's Galilean Moons (which include Io, Ganymede, and Callisto), Europa's deep interior is composed of mostly of silicate rock.

Trailing Planets
10.05.2002

Positioning his camera and tripod on planet Earth, near Maricopa, Arizona, USA, astrophotographer Joe Orman created this trailing display of the ongoing sky-full-of-planets on May 3rd. He initially captured the grouping in a 20 second long time exposure recording the positions of the bright planets and stars.