Phi Persei: Double Star
2.10.1999

It's clear who is the biggest star in this binary system. Based on recent results, this artist's vision of the double star Phi Persei, 720 light years away, shows a bright, rapidly rotating massive star surrounded by a disk of gas. A small companion star orbits 100 million miles away.

Saturns Northern Hexagon
5.07.2020

Why would clouds form a hexagon on Saturn? Nobody is sure. Originally discovered during the Voyager flybys of Saturn in the 1980s, nobody has ever seen anything like it anywhere else in the Solar System.

APOD: 2023 June 18 Б Saturns Northern Hexagon
18.06.2023

Why would clouds form a hexagon on Saturn? Nobody is sure. Originally discovered during the Voyager flybys of Saturn in the 1980s, nobody has ever seen anything like it anywhere else in the Solar System.

Sun Spot Hill
21.09.2021

Is this giant orange ball about to roll down that tree-lined hill? No, because the giant orange ball is actually the Sun. Our Solar System's central star was captured rising beyond a hill on Earth twelve days ago complete with a delightfully detailed foreground.

Four X-class Flares
16.05.2013

Swinging around the Sun's eastern limb on Monday, a group of sunspots labeled active region AR1748 has produced the first four X-class solar flares of 2013 in less than 48 hours. In time sequence clockwise from the top left, flashes from the four were captured in extreme ultraviolet images from the Solar Dynamics Observatory.

Earth Flyby of BepiColombo
4.05.2020

What it would look like to approach planet Earth? Such an event was recorded visually in great detail by ESA's and JAXA's robotic BepiColombo spacecraft last month as it swung back past Earth on its journey in to the planet Mercury.

Circumpolar Star Trails
18.01.2019

As Earth spins on its axis, the stars appear to rotate around an observatory in this well-composed image from the Canary Island of Tenerife. Of course, the colorful concentric arcs traced out by the stars are really centered on the planet's North Celestial Pole.

Earth, Clouds, Sky, Comet
3.04.1997

Does a comet's dust tail always orbit behind it? Since comets rotate, they shed gas and dust in all directions equally. Small ice and dust particles expelled by the comet, however, are literally pushed around by sunlight. The smaller the particle, the greater the effect.

Night on Venus in Infrared from Orbiting Akatsuki
7.06.2016

Why is Venus so different from Earth? To help find out, Japan launched the robotic Akatsuki spacecraft which entered orbit around Venus late last year after an unplanned five-year adventure around the inner Solar System.

The Shadow of Phobos
29.03.2003

Hurtling through space above the Red Planet, potato-shaped Phobos completes an orbit of Mars in less than eight hours. In fact, since its orbital period is shorter than the planet's rotation period, Mars-based...