The Spiral North Pole of Mars
19.12.2017

Why is there a spiral around the North Pole of Mars? Each winter this pole develops a new outer layer about one meter thick composed of carbon dioxide frozen out of the thin Martian atmosphere. This fresh layer is deposited on a water-ice layer that exists year round.

Comet CG Evaporates
27.01.2020

Where do comet tails come from? There are no obvious places on the nuclei of comets from which the jets that create comet tails emanate. One of the best images of emerging jets...

The Seasons of Saturn
21.07.2013

Since Saturn's axis is tilted as it orbits the Sun, Saturn has seasons, like those of planet Earth ... but Saturn's seasons last for over seven years. So what season is it on Saturn now? Orbiting the equator, the tilt of the rings of Saturn provides quite a graphic seasonal display.

M51: X Rays from the Whirlpool
10.06.2014

What if we X-rayed an entire spiral galaxy? This was done (again) recently by NASA's Chandra X-ray Observatory for the nearby interacting galaxies known as the Whirlpool (M51). Hundreds of glittering x-ray stars are present in the above Chandra image of the spiral and its neighbor.

NGC 346: Star Forming Cluster in the SMC
1.12.2020

Are stars still forming in the Milky Way's satellite galaxies? Found among the Small Magellanic Cloud's (SMC's) clusters and nebulas, NGC 346 is a star forming region about 200 light-years across, pictured here in the center of a Hubble Space Telescope image.

Hubble Remix: Active Galaxy NGC 1275
6.10.2013

Active galaxy NGC 1275 is the central, dominant member of the large and relatively nearby Perseus Cluster of Galaxies. Wild-looking at visible wavelengths, the active galaxy is also a prodigious source of x-rays and radio emission.

Sunspot Group AR 2339 Crosses the Sun
29.06.2015

How do sunspots evolve? Large dark sunspots -- and the active regions that contain them -- may last for weeks, but all during that time they are constantly changing. Such variations were particularly apparent...

AE Aurigae and the Flaming Star Nebula
10.11.2015

Is star AE Aurigae on fire? No. Even though AE Aurigae is named the flaming star, the surrounding nebula IC 405 is named the Flaming Star Nebula, and the region appears to have the color of fire, there is no fire.

Sound and Light Captured by Mars InSight
10.12.2018

Your arm on Mars has unusual powers. For one thing it is nearly 2 meters long, has a scoop and grapple built into its hand, and has a camera built into its forearm. For another, it will soon deploy your ear -- a sensitive seismometer that will listen for distant rumblings -- onto the surface of Mars.

Galaxy NGC 474: Shells and Star Streams
5.01.2014

What's happening to galaxy NGC 474? The multiple layers of emission appear strangely complex and unexpected given the relatively featureless appearance of the elliptical galaxy in less deep images. The cause...