Globular Cluster M5
19.10.1995

The globular cluster M5, pictured above, contains roughly 100,000 stars. These stars formed together and are gravitationally bound. Stars orbit the center of the cluster, and the cluster orbits the center of our Galaxy. So far, about 160 globular clusters are known to exist in a roughly spherical halo around the Galactic center.

Globular Cluster M22 from CFHT
27.06.2005

The globular cluster M22, pictured above, contains over 100,000 stars. These stars formed together and are gravitationally bound. Stars orbit the center of the cluster, and the cluster orbits the center of our Galaxy. So far, about 140 globular clusters are known to exist in a roughly spherical halo around the Galactic center.

Almost Three Tails for Comet Encke
20.02.2017

How can a comet have three tails? Normally, a comet has two tails: an ion tail of charged particles emitted by the comet and pushed out by the wind from...

Juno Approaching Jupiter
1.07.2016

Approaching over the north pole after nearly a five-year journey, Juno enjoys a perspective on Jupiter not often seen, even by spacecraft from Earth that usually swing by closer to Jupiter's equator. Looking...

Oceans Under Jupiter's Ganymede
18.12.2000

The search for extraterrestrial life came back into our own Solar System last week with the announcement that there may be liquid oceans under the surface of Jupiter's moon Ganymede. Ganymede now joins Callisto and Europa as moons of Jupiter that may harbor seas of liquid water under layers of surface ice.

Solar Flare from a Sharper Sun
21.11.2014

Solar active region AR2192 was the largest recorded sunspot group of the last 24 years. Before rotating off the Earth-facing side of the Sun at the end of October, it produced a whopping six energetic X-class flares.

A Dangerous Summer on HD 80606b
4.02.2009

On the distant planet HD 80606b, summers might be dangerous. Hypothetic life forms floating in HD 080606b's atmosphere or lurking on one of its (presently hypothetical) moons might fear the 1,500 Kelvin summer heat, which is hot enough not only to melt lead but also nickel.

Fomalhaut's Dusty Debris Disk
11.05.2023

Fomalhaut is a bright star, a 25 light-year voyage from planet Earth in the direction of the constellation Piscis Austrinus. Astronomers first noticed Fomalhaut's excess infrared emission in the 1980s. Space and ground-based...

Clouds Near Jupiters South Pole from Juno
25.10.2016

What's happening near the south pole of Jupiter? Recent images sent back by NASA's robotic Juno spacecraft are showing an interesting conglomeration of swirling clouds and what appear to be white ovals.

Lightning on Jupiter
12.05.1997

Does lightning occur only on Earth? Spacecraft in our Solar System have detected radio signals consistent with lightning on other planets, including Venus, Jupiter, Saturn, Uranus, and Neptune. In the above photograph, optical flashes from Jupiter were photographed recently by the Galileo orbiter. Each of the circled dots indicates lightning.