The Protoplanetary Disk of HL Tauri from ALMA
9.11.2014

Why does this giant disk have gaps? The exciting and probable answer is: planets. A mystery is how planets massive enough to create these gaps formed so quickly, since the HL Tauri star system is only about one million years old.

Two Worlds One Sun
12.05.2015

How different does sunset appear from Mars than from Earth? For comparison, two images of our common star were taken at sunset, one from Earth and one from Mars. These images were scaled to have same angular width and featured here side-by-side.

NGC 1499: The California Nebula
23.08.2019

Drifting through the Orion Arm of the spiral Milky Way Galaxy, this cosmic cloud by chance echoes the outline of California on the west coast of the United States. Our own Sun also lies within the Milky Way's Orion Arm, only about 1,500 light-years from the California Nebula.

Rosetta's Comet in View
10.09.2021

Faint comet Churyumov-Gerasimenko (67P) sweeps past background stars in the constellation Taurus and even fainter distant galaxies in this telescopic frame from September 7. About 5 years ago, this comet's 4 kilometer spanning...

Rigel and the Witch Head Nebula
31.10.2024

By starlight, this eerie visage shines in the dark with a crooked profile evoking its popular name, the Witch Head Nebula. In fact, this entrancing telescopic portrait gives the impression that a witch has fixed her gaze on Orion's bright supergiant star Rigel.

APOD: 2025 March 16 Б Venus and the Triply Ultraviolet Sun
16.03.2025

This was a very unusual type of solar eclipse. Typically, it is the Earth's Moon that eclipses the Sun. In 2012, though, the planet Venus took a turn. Like a solar eclipse by the Moon, the phase of Venus became a continually thinner crescent as Venus became increasingly better aligned with the Sun.

APOD: 2025 September 26 Б A SWAN an ATLAS and Mars
26.09.2025

A new visitor to the inner Solar System, comet C/2025 R2 (SWAN) sports a long ion tail extending diagonally across this almost 7 degree wide telescopic field of view recorded on September 21.

Comet Hale-Bopp Over Val Parola Pass
17.03.1997

Comet Hale-Bopp is now much brighter than any surrounding stars. It can be seen even over bright city lights. Out away from city lights, however, it is putting on quite a spectacular show. Here Comet Hale-Bopp was photographed last week above Val Parola Pass in the Dolomite mountains surrounding Cortina d'Ampezzo, Italy.

A Late Leonid from a Sparse Shower
25.11.2003

The 2003 Leonids Meteor Shower contained relatively few meteors. As expected and unlike the last few years, the Earth just did not pass through any dense particle streams left over by the Sun-orbiting Comet Tempel-Tuttle.

Tempel Tuttle: The Leonid Comet
13.11.1999

Star trails streak this composite time exposure of Comet Tempel-Tuttle recorded by T. Puckett on January 26, 1998. Then passing through the inner solar system on its 33 year orbit around the Sun, Tempel-Tuttle brightened unexpectedly, but binoculars or small telescopes were still required to visually observe it.