Rings and Seasons of Saturn
21.06.2015

On Saturn, the rings tell you the season. On Earth, today marks a solstice, the time when the Earth's spin axis tilts directly toward the Sun. On Earth's northern hemisphere, today is the Summer Solstice, the day of maximum daylight.

Orion over the Central Bohemian Highlands
18.02.2020

Do you recognize this constellation? Setting past the Central Bohemian Highlands in the Czech Republic is Orion, one of the most identifiable star groupings on the sky and an icon familiar to humanity for over 30,000 years.

The Horsehead and Flame Nebulas
3.11.2021

The Horsehead Nebula is one of the most famous nebulae on the sky. It is visible as the dark indentation to the orange emission nebula at the far right of the featured picture. The horse-head feature is dark because it is really an opaque dust cloud that lies in front of the bright emission nebula.

Mu Cephei
12.10.2023

Mu Cephei is a very large star. An M-class supergiant some 1500 times the size of the Sun, it is one of the largest stars visible to the unaided eye, and even one of the largest in the entire Galaxy.

Ringside with Titan and Dione
5.01.2012

Orbiting in the plane of Saturn's rings, Saturnian moons have a perpetual ringside view of the gorgeous gas giant planet. Of course, while passing near the ring plane the Cassini spacecraft also shares their stunning perspective.

Jets from Comet Churyumov Gerasimenko
2.02.2015

Where do comet tails come from? Although it is common knowledge that comet tails and comas originate from comet nuclei, exactly how that happens is an active topic of research. One of the best...

The Whirlpool Galaxy and Beyond
6.09.2016

Follow the handle of the Big Dipper away from the dipper's bowl, until you get to the handle's last bright star. Then, just slide your telescope a little south and west and you might find this stunning pair of interacting galaxies, the 51st entry in Charles Messier's famous catalog.

The Red Spider Planetary Nebula
19.04.2017

Oh what a tangled web a planetary nebula can weave. The Red Spider Planetary Nebula shows the complex structure that can result when a normal star ejects its outer gases and becomes a white dwarf star.

Atmospheric Ring of Venus
8.06.2020

Why is Venus surrounded by a bright ring? Sometimes called a ring of fire, this rare ring is caused by the Sun's light being visible all around an object. Usually seen around...

A Green Flash from the Sun
4.01.2011

Many think it is just a myth. Others think it is true but its cause isn't known. Adventurers pride themselves on having seen it. It's a green flash from the Sun. The truth is the green flash does exist and its cause is well understood.