The 60 inch Reflector
13.12.2008

On the night of December 13, 1908, 100 years ago today, the 60-inch diameter reflecting telescope of Mount Wilson Observatory was first tested on the stars. It became the first successful large reflecting telescope.

Lunar Occultation of Venus
2.06.2022

On May 27 Venus rose as the morning star, near the waning crescent Moon in a predawn sky already full of planets. It was close on the sky to the Moon's crescent and a conjunction of the second an third brightest celestial beacons were enjoyed by skygazers around the world.

Late Night Vallentuna
15.08.2024

Bright Mars and even brighter Jupiter are in close conjunction just above the pine trees in this post-midnight skyscape from Vallentuna, Sweden. Taken on August 12 during a geomagnetic storm, the snapshot records the glow of aurora borealis or northern lights, beaming from the left side of the frame.

Chilean Skyscape
29.11.2008

Night skies over Chilean mountain top observatories can be dark and clear, with glorious cosmic vistas. In this recent example, the plane of our Milky Way galaxy stretches parallel to the horizon, the galactic center's star clusters, dark dust clouds, and glowing nebulae hovering in the west.

APOD: 2026 April 24 Б Young Moon and Sister Stars
24.04.2026

Sunlit arms of a crescent moon seem to embrace the faint lunar night side in this dramatic celestial scene from planet Earth. The single telephoto exposure tracking the sky was captured on the night of April 19, when a two day old Moon was near perigee in its elliptical orbit.

Massive Black Hole Shreds Passing Star
28.10.2015

What happens when a star gets too close to a black hole? Recent observations from Earth-orbiting observatories of an event dubbed ASASSN-14li, in a distant galactic center, appears to be giving one star's harrowing story.

Mars in Taurus
4.03.2021

You can spot Mars in the evening sky tonight. Now home to the Perseverance rover, the Red Planet is presently wandering through the constellation Taurus, close on the sky to the Seven Sisters or Pleiades star cluster.

First Launch of the Delta IV Heavy
26.01.2005

The new Delta IV Heavy Launch Vehicle is the largest rocket ever to be launched by the US Air Force. The Delta IV Heavy is capable of launching over 23,000 kilograms into low Earth orbit.

Solstice: Sunrises Around the Year
21.12.2020

Does the Sun always rise in the same direction? No. As the months change, the direction toward the rising Sun changes, too. The featured image shows the direction of sunrise every month during 2019 as seen from near the city of Amman, Jordan.

Zodiacal Light and Mars
11.03.2021

Just after sunset on March 7, a faint band of light still reaches above the western horizon in this serene, rural Illinois, night skyscape. Taken from an old farmstead, the luminous glow is zodiacal light, prominent in the west after sunset during planet Earth's northern hemisphere spring.