Perihelion to Aphelion
9.01.2020

Perihelion for 2020, the point in Earth's elliptical orbit when it is closest to the Sun, occurred on January 5th. The distance from the Sun doesn't determine the seasons, though. Those...

APOD: 2020 August 2 Б Two Worlds One Sun
2.08.2020

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.

APOD: 2025 June 15 Б Two Worlds One Sun
15.06.2025

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 the same angular width and are featured here side-by-side.

APOD: 2025 September 13 Б Star Trails over One Mile Radio Telescope
13.09.2025

The steerable 60 foot diameter dish antenna of the One-Mile Telescope at Mullard Radio Astronomy Observatory, Cambridge, UK, is pointing skyward in this evocative night-skyscape. To capture the dramatic scene, consecutive 30 second exposures were recorded over a period of 90 minutes.

A Ring of Fire Sunrise Solar Eclipse
15.06.2020

What's rising above the horizon behind those clouds? It's the Sun. Most sunrises don't look like this, though, because most sunrises don't include the Moon. In the early morning of 2013 May 10, however, from Western Australia, the Moon was between the Earth and the rising Sun.

December s Comet Wirtanen
7.12.2018

Coming close in mid-December, Comet 46P Wirtanen hangs in this starry sky over the bell tower of a Romanesque church. In the constructed vertical panorama, a series of digital exposures capture its greenish coma on December 3 from Sant Llorenc de la Muga, Girona, Catalonia, Spain, planet Earth.

A Meteor Wind over Tunisia
16.08.2022

Does the Earth ever pass through a wind of meteors? Yes, and they are frequently visible as meteor showers. Almost all meteors are sand-sized debris that escaped from a Sun-orbiting comet or asteroid, debris that continues in an elongated orbit around the Sun.

APOD: 2025 November 4 Б Comet Lemmon Beyond Lomnickц Peak
4.11.2025

Comet Lemmon has been putting on a show for cameras around the globe. Passing nearest to Earth in late October, the photogenic comet C/2025 A6 (Lemmon) sprouted two long and picturesque tails: a blue ion tail and a white dust tail.

A Small Double Ozone Hole in 2002
22.10.2002

As expected, the ozone hole near Earth's South Pole is back again this year. This time, however, it's smaller than the past two years, and has an unusual double lobe structure. Ozone is important because it shields us from damaging ultraviolet sunlight.

Grand Canyon Star Trails
3.03.2013

One of the natural wonders of planet Earth, the Grand Canyon in the American southwest stretches across this early evening skyscape. The digitally stacked sequence reveals the canyon's layers of sedimentary rock in bright moonlight.