Red Sprite Lightning over Kununurra
25.02.2019

What are those red filaments in the sky? It is a rarely seen form of lightning confirmed only about 30 years ago: red sprites. Recent research has shown that following a powerful positive cloud-to-ground...

Noctilucent Clouds, Reflections, and Silhouettes
26.06.2019

Sometimes it's night on the ground but day in the air. As the Earth rotates to eclipse the Sun, sunset rises up from the ground. Therefore, at sunset on the ground, sunlight still shines on clouds above.

Tianwen 1 Mission to Mars
25.07.2020

On July 23, this Long March 5 heavy-lift rocket rose into a blue morning sky from China's Hainan Island Wenchang Satellite Launch Center. The rocket carried an orbiter, lander, and rover to ask Heavenly Questions on the ambitious Tianwen-1 mission to Mars.

A Halo for Andromeda
3.09.2020

M31, the Andromeda Galaxy, is the closest large spiral galaxy to our Milky Way. Some 2.5 million light-years distant it shines in Earth's night sky as a small, faint, elongated cloud just visible to the unaided eye.

Perseid Outburst at Westmeath Lookout
24.09.2021

This year an outburst of Perseid meteors surprised skywatchers. The reliable meteor shower's peak was predicted for the night of August 12/13. But persistent visual observers in North America were deluged with...

Quadrantids of the North
8.01.2022

Named for a forgotten constellation, the Quadrantid Meteor Shower puts on an annual show for planet Earth's northern hemisphere skygazers. The shower's radiant on the sky lies within the old, astronomically obsolete constellation Quadrans Muralis.

Mercury from Passing BepiColombo
28.06.2022

Which part of the Moon is this? No part -- because this is the planet Mercury. Mercury's old surface is heavily cratered like that of Earth's Moon. Mercury, while only slightly larger than Luna, is much denser and more massive than any Solar System moon because it is made mostly of iron.

Solargraphic Analemmas
2.07.2022

For the northern hemisphere June 21 was the summer solstice, the Sun reaching its northernmost declination for the year. That would put it at the top of each of these three figure-8 curves, or analemmas, as it passed through the daytime sky over the village of Proboszczow, Poland.

In the Arms of NGC 1097
16.11.2022

Spiral galaxy NGC 1097 shines in southern skies, about 45 million light-years away in the heated constellation Fornax. Its blue spiral arms are mottled with pinkish star forming regions in this colorful galaxy portrait.

Full Moons of August
30.08.2023

Near perigee, the closest point in its almost moonthly orbit, a Full Moon rose as the Sun set on August 1. Its brighter than average lunar disk was captured in this dramatic moonrise sequence over dense cloud banks along the eastern horizon from Ragusa, Sicily.