Rays from an Unexpected Aurora
5.08.2002

This aurora was a bit of a surprise. For starters, last Friday morning, no intense auroral activity was expected at all. Possibly more surprising, however, the aurora appeared to show an usual structure of green rays from some locations.

A Taurid Meteor Fireball
15.11.2005

Have you ever seen a very bright meteor? Unexpected, this year's Taurid meteor shower resulted in numerous reports of very bright fireballs during the nights surrounding Halloween. Pictured above, a fireball that momentarily rivaled the brightness of the full Moon was caught over Cerro Pachon, Chile by a continuous sky monitor on November 1.

Planets in the West
24.06.2005

This weekend three planets will grace the western sky, forming a lovely trio easily visible shortly after sunset. Saturday evening in particular will find Saturn, Venus, and Mercury all within a 2 degree circle (about the size of your thumb held at arm's length) above the western horizon.

APOD: 2023 February 28 Б Crescent Moon Beyond Greek Temple
28.02.2023

Why is a thin crescent moon never seen far from a horizon? Because the only geometry that gives a thin crescent lunar phase occurs when the Moon appears close to the Sun in the sky.

Strawberry to Honey Moonrise
25.06.2016

Near the horizon the Full Moon often seems to loom large, swollen in appearance by the famous Moon illusion. But timelapse images demonstrate that the Moon's apparent size doesn't really change as it climbs toward the zenith. Its color does, though.

Noctilucent NEOWISE
9.07.2020

These silvery blue waves washing over a tree-lined horizon in the eastern French Alps are noctilucent clouds. From high in planet Earth's mesosphere, they reflect sunlight in this predawn skyscape taken on July 8. This summer, the night-shining clouds are not new to the northern high-latitudes. Comet NEOWISE is though.

Dawn s Grande Finale
4.06.2011

After more than a month, the lovely lineup of four naked-eye planets in dawn skies is coming to a close. Still, on May 31st a slender Moon joined the grouping along the eastern horizon for a final celestial performance, presented in this early morning scene from a beach near Buenos Aires, Argentina.

APOD: 2024 October 14 Б Comet Tsuchinshan ATLAS Over the Lincoln Memorial
14.10.2024

Go outside at sunset tonight and see a comet! C/2023 A3 (TsuchinshanБATLAS) has become visible in the early evening sky in northern locations to the unaided eye. To see the comet, look west through a sky with a low horizon.

Comet Lovejoy and the ISS
31.12.2011

On December 24, Comet Lovejoy rose in dawn's twilight, arcing above the eastern horizon, its tails swept back by the solar wind and sunlight. Seen on the left is the comet's early morning appearance alongside the southern Milky Way from the town of Intendente Alvear, La Pampa province, Argentina.

A Fisheye View of Comet Hale-Bopp
25.08.1997

Thousands of stars, several constellations, a planet and a comet all graced the western horizon over Ujue, Spain just after sunset on April 4th, 1997. Because the picture was taken with a fisheye lens, much of the whole night sky is visible. Comet Hale-Bopp, with both tails blazing, appears right of center.