Lightning over Colorado
4.12.2016

Have you ever watched a lightning storm in awe? Join the crowd. Oddly, nobody knows exactly how lightning is produced. What is known is that charges slowly separate in some clouds causing rapid electrical discharges (lightning), but how electrical charges get separated in clouds remains a topic of much research.

The Einstein Cross Gravitational Lens
16.12.2017

Most galaxies have a single nucleus -- does this galaxy have four? The strange answer leads astronomers to conclude that the nucleus of the surrounding galaxy is not even visible in this image. The central cloverleaf is rather light emitted from a background quasar.

Comet ZTF over Mount Etna
27.01.2023

Comet-like plumes are blowing over the volcanic peaks of Mount Etna in this wintry mountain-and-skyscape from planet Earth. The stacked and blended combination of individual exposures recorded during the cold night of January 23, also capture naked-eye Comet ZTF just above Etna's snowy slopes.

The Creature from the Red Lagoon
24.11.2014

What creature lurks near the red Lagoon nebula? Mars. This gorgeous color deep-sky photograph has captured the red planet passing below two notable nebulae -- cataloged by the 18th century cosmic registrar Charles Messier as M8 and M20.

The Seahorse of the Large Magellanic Cloud
29.11.2014

It may look like a grazing seahorse, but the dark object toward the image right is actually a pillar of smoky dust about 20 light years long. The curiously-shaped dust structure occurs in our neighboring Large Magellanic Cloud, in a star forming region very near the expansive Tarantula Nebula.

Tyrrhenian Sea and Solstice Sky
20.12.2014

Today the solstice occurs at 23:03 Universal Time, the Sun reaching its southernmost declination in planet Earth's sky. Of course, the December solstice marks the beginning of winter in the northern hemisphere and summer in the south.

Comet PanSTARRS, Moon, and Venus
22.07.2015

It is the object to the left of the big tree that's generating much recent excitement. If you look closely, there you can see Comet PanSTARRS, complete with two tails. During July, this comet has increased markedly in brightness and has just passed its closest approach to Earth.

M31: The Andromeda Galaxy
16.12.2018

What is the nearest major galaxy to our own Milky Way Galaxy? Andromeda. In fact, our Galaxy is thought to look much like Andromeda. Together these two galaxies dominate the Local Group of galaxies. The diffuse light from Andromeda is caused by the hundreds of billions of stars that compose it.

Road to the Galactic Center
24.10.2021

Does the road to our galaxy's center go through Monument Valley? It doesn't have to, but if your road does -- take a picture. In this case, the road is US Route 163 and iconic buttes on the Navajo National Reservation populate the horizon.

Planetary Alignment over Italy
18.12.2021

It is not a coincidence that planets line up. That's because all of the planets orbit the Sun in (nearly) a single sheet called the plane of the ecliptic. When viewed from inside that plane -- as Earth dwellers are likely to do -- the planets all appear confined to a single band.