Storm Alley on Saturn
1.11.2004

What causes storms on Saturn? To help find out, scientists commanded the robot Cassini spacecraft now orbiting Saturn to inspect a circulating band of clouds nicknamed "Storm Alley." This westwardly moving cloud ring...

Welcome to Perihelion
3.01.2025

Earth's orbit around the Sun is not a circle, it's an ellipse. The point along its elliptical orbit where our fair planet is closest to the Sun is called perihelion. This year perihelion is today, January 4, at 13:28 UTC, with the Earth about 147 million kilometers from the Sun.

Sunrise Analemma
19.03.2003

Astronomically speaking, at the Equinox on March 21, 01:00 UT (March 20, 8:00 PM ET) the season changes. For this Equinox the Sun rises due east as it crosses the celestial equator heading north. In celebration, consider this spectacular sunrise analemma!

Neptune: Still Springtime After All These Years
26.06.2004

In the 1960s spring came to the southern hemisphere of Neptune, the Solar System's outermost gas giant planet. Of course, since Neptune orbits the Sun once every 165 earth-years, it's still springtime for southern Neptune, where each season lasts over four decades.

Moons, Rings, and Unexpected Colors on Saturn
20.10.2008

Why would Saturn show such strange colors? The robotic Cassini spacecraft currently orbiting Saturn has beamed back images showing that the northern hemisphere our Solar System's most spectacularly ringed planet has changed noticeably since Cassini arrived in 2004, now sporting unusual and unexpected colors. No one is sure why.

Solstice Sun and Milky Way
20.12.2021

Welcome to December's solstice, first day of winter in the north and summer for the southern hemisphere. Astronomical markers of the seasons, solstice and equinox dates are based on the Sun's place in its annual journey along the ecliptic, through planet Earth's sky.

APOD: 2024 February 25 Б A Phoenix Aurora over Iceland
24.02.2024

All of the other aurora watchers had gone home. By 3:30 am in Iceland, on a quiet September night, much of that night's auroras had died down. Suddenly, unexpectedly, a new burst of particles streamed down from space, lighting up the Earth's atmosphere once again.

Summer to Winter Milky Way
18.10.2018

Taken near local midnight, this autumn night's panorama follows the arch of the Milky Way across the northern horizon from the High Fens, Eifel Nature Park at the border of Belgium and Germany.

Hale-Bopp on Schedule
25.07.1996

Late March and early April of 1996 marked a banner season for viewing the spectacular naked-eye comet Hyakutake. The spring of 1997 could well offer a similar cometary wonder, Comet Hale-Bopp. Discovered last year while approaching the inner solar sytem Hale-Bopp has been eagerly watched for signs that it will indeed brighten spectacularly.

Southern Annular Eclipse
26.04.2014

It's eclipse season, and on April 29 around 06:00 UT the shadow of the new Moon will reach out and touch planet Earth, though only just. Still, if you're standing...