APOD: 2025 December 30 Б An Artificial Comet
30.12.2025

Yes, but can your comet tail do this? No, and what you are seeing is not the tail of a comet. The picture features a cleverly overlayed time-lapse sequence of a group of satellites orbiting Earth together in June.

APOD: 2025 October 15 Б Rocket Launch Plume over Tucson
15.10.2025

Yes, but can your sunset do this? Looking west from Tucson, Arizona, USA one day last month, the sunset sky looked strange when it briefly lit up with the plume of a rocket launched from California a few minutes earlier.

Martian Sunset
2.03.2014

What would it be like to see a sunset on Mars? To help find out, the robotic rover Spirit was deployed in 2005 to park and watch the Sun dip serenely below the distant lip of Gusev crater.

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.

Layer Cake Sunset
20.01.2017

On January 18 a tantalizing sunset was captured in this snapshot. Seemingly sliced into many horizontal layers the Sun shimmered moments before it touched the horizon, setting over the Pacific Ocean as seen from the mountaintop Las Campanas Observatory in Chile.

APOD: 2025 December 22 Б Sunset Solstice over Stonehenge
22.12.2025

Yesterday the Sun reached its southernmost point in planet Earth's sky. Called a solstice, many cultures mark yesterday's date as a change of seasons -- from autumn to winter in Earth's Northern Hemisphere and from spring to summer in Earth's Southern Hemisphere.

When the Moon Was Young
13.05.2005

Remember when the Moon was young? It was just last Monday. On May 9th, this slender crescent Moon was recorded at a tender age of 34 hours and 18 minutes. Well, OK ... when calculating...

An Iridium Flash Sunset
2.05.2000

Did you see that flash? Lasting only about 15 seconds, it's possible that nobody you ask can confirm it, but what you might have seen is sunlight reflecting off an orbiting Iridium satellite. Satellites of all types have been providing streaks and glints visible only since the launch of Sputnik I in 1957.

A Green Flash from the Sun
7.05.2000

Many think it is just a myth. Others think it is true but its cause isn't known. Adventurers pride themselves on having seen it. It's a green flash from the Sun. The truth is the green flash does exist and its cause is well understood.