Dark Sun Sizzling
10.07.2006

Is this our Sun? Yes. Even on a normal day, our Sun is sizzling ball of seething hot gas. Unpredictably, regions of strong and tangled magnetic fields arise, causing sunspots and bright active regions. The Sun's surface bubbles as hot hydrogen gas streams along looping magnetic fields.

Solstice to Solstice Solargraph Timelapse
21.12.2019

The 2019 December Solstice, on the first day of winter in planet Earth's northern hemisphere and summer in the south, is at 4:19 Universal Time December 22. That's December 21 for North America, though. Celebrate with a timelapse animation of the Sun's seasonal progression through the sky.

The Arms of M106
6.02.2013

The spiral arms of bright galaxy M106 sprawl through this remarkable multiframe portrait, composed of data from ground- and space-based telescopes. Also known as NGC 4258, M106 can be found toward the northern constellation Canes Venatici. The well-measured distance to M106 is 23.5 million light-years, making this cosmic scene about 80,000 light-years across.

Supernova Remnant E0102 72 from Radio to X-Ray
14.04.2000

Not all stars form a big Q after they explode. The shape of supernova remnant E0102-72, however, is giving astronomers a clue about how tremendous explosions disperse elements and interact with surrounded gas. The above image is a composite of three different photographs in three different types of light.

PG 1115: A Ghost of Lensing Past
2.11.1998

In this tangle of quasars and galaxies lies a clue to the expansion rate of the universe. A diffuse glow evident in the picture on the left reveals a normal elliptical galaxy. Directly behind this galaxy lies a normal quasar.

When Z is for Mars
15.04.2023

A composite of images captured about a week apart from mid August 2022 through late March 2023, this series traces the retrograde motion of ruddy-colored Mars. Progressing from lower right to upper left Mars...

The W in Cassiopeia
18.03.2016

A familiar, zigzag, W pattern in northern constellation Cassiopeia is traced by five bright stars in this colorful and broad mosaic. Stretching about 15 degrees across rich starfields, the celestial scene includes dark clouds, bright nebulae, and star clusters along the Milky Way. In yellow-orange hues Cassiopeia's alpha star Shedar is a standout though.

Polaris and the Trail of Comet ZTF
3.02.2023

Stars trace concentric arcs around the North Celestial Pole in this three hour long night sky composite, recorded with a digital camera fixed to a tripod on January 31, near цger, Lleida, Spain. On that date Comet C/2022 E3 (ZTF) was near its northernmost declination in planet Earth's sky.

APOD: 2025 June 21 Б Two Worlds, Two Analemmas
21.06.2025

Sure, that figure-8 shaped curve you get when you mark the position of the Sun in Earth's sky at the same time each day over one year is called an analemma.

Star Trails in Northern Skies
12.09.1998

As the Earth spins on its axis, the sky seems to rotate around us. This motion produces the beautiful concentric trails traced by the stars in this time exposure of the night sky.