Coronal Hole
7.02.2002

This ominous, dark shape sprawling across the face of the active Sun is a coronal hole -- a low density region extending above the surface where the solar magnetic field opens freely into interplanetary space.

Large Sunspot Groups 10484 and 10486
27.10.2003

Two unusually large sunspot groups are now crossing the face of the Sun. Each group, roughly the size of Jupiter, is unusual not only for its size but because it is appearing over three years after solar maximum, the peak of solar surface activity.

Sedna of the Outer Solar System
16.03.2004

What is the most distant known object in our Solar System? A new answer to this centuries-old question was announced yesterday by NASA with the discovery of a dark red object dubbed Sedna. Although over twice the distance to Pluto, Sedna is near its closest approach to the Sun.

Solstice: Sunrises Around the Year
21.12.2020

Does the Sun always rise in the same direction? No. As the months change, the direction toward the rising Sun changes, too. The featured image shows the direction of sunrise every month during 2019 as seen from near the city of Amman, Jordan.

WR32 and Interstellar Clouds in Carina
8.02.2021

Stars can be like artists. With interstellar gas as a canvas, a massive and tumultuous Wolf-Rayet star has created the picturesque ruffled half-circular filaments called WR32, on the image left. Additionally, the winds...

Galaxies in the River
27.11.2008

Large galaxies grow by eating small ones. Even our own galaxy practices galactic cannibalism, absorbing small galaxies that get too close and are captured by the Milky Way's gravity. In fact, the practice...

Orange Sun Simmering
9.06.2010

Even a quiet Sun can be a busy place. And over the deep Solar Minimum of the past few years, our Sun has been unusually quiet. The above image, taken last week...

M33: The Triangulum Galaxy
31.12.2019

The small, northern constellation Triangulum harbors this magnificent face-on spiral galaxy, M33. Its popular names include the Pinwheel Galaxy or just the Triangulum Galaxy. M33 is over 50,000 light-years in diameter, third largest in the Local Group of galaxies after the Andromeda Galaxy (M31), and our own Milky Way.

M33: The Triangulum Galaxy
12.11.2021

The small, northern constellation Triangulum harbors this magnificent face-on spiral galaxy, M33. Its popular names include the Pinwheel Galaxy or just the Triangulum Galaxy. M33 is over 50,000 light-years in diameter, third largest in the Local Group of galaxies after the Andromeda Galaxy (M31), and our own Milky Way.

The Bay of Rainbows
12.02.2026

Dark, smooth regions that cover the Moon's familiar face are called by Latin names for oceans and seas. That naming convention is historical, though it may seem a little ironic to denizens...