All posts by Justin Avery

Justin spends most of his time creating notebooks about space, and far too little time maintaining this site.

Comet Catalina Hemmerich_1821

Comet Catalina Emerges

The Catalina comet is getting closer and closer to us right now and will reach it’s closest point in January. It’s so close at the moment that you can see it in the sky in the morning (from about 5am...

/ December 8, 2015
casimir sphere

A Force from Empty Space: The Casimir Effect

This image denotes a ball that is moving even though there are no visible forces acting upon it in a vacuum (and if the image seems weird it’s because the ball is only around 1/10th of a millimetre). This small...

/ December 7, 2015
Cygnus: Bubble and Crescent

Cygnus: Bubble and Crescent

The clouds of gas and dust that you see are remnants of an exploded star.  The gas and dust spreads out into the Universe and awaits an opportunity to once again clump together and reform into a new star, planet...

/ December 5, 2015
Enceladus Rings

Enceladus: Ringside Water World

Saturn’s icy moon Enceladus poses above the gas giant’s icy rings in this Cassini spacecraft image. The dramatic scene was captured on July 29, while Cassini cruised just below the ring plane, its cameras looking back in a nearly sunward...

/ December 4, 2015
Nebulae in Auriga

Nebulae in Aurigae

Rich in star clusters and nebulae, the ancient constellation of the Charioteer (Auriga) rides high in northern winter night skies. Composed from narrow and broadband filter data and spanning nearly 8 Full Moons (4 degrees) on the sky, this deep...

/ December 2, 2015

In the Center of Spiral Galaxy NGC 3521

This huge swirling mass of stars, gas, and dust occurs near the center of a nearby spiral galaxy. Gorgeous spiral NGC 3521 is a mere 35 million light-years distant, toward the constellation Leo. Spanning some 50,000 light-years, its central region...

/ December 1, 2015

Dark Sand Cascades on Mars

They might look like trees on Mars, but they’re not. Groups of dark brown streaks have been photographed by the Mars Reconnaissance Orbiter on melting pinkish sand dunes covered with light frost. The above image was taken in 2008 April...

/ November 30, 2015

Rosetta and Comet Outbound

Not a bright comet, 67P/Churyumov-Gerasimenko now sweeps slowly through planet Earth’s predawn skies near the line-up of planets along the ecliptic. Still, this composite of telescopic images follows the comet’s progress as it moves away from the Sun beyond the...

/ November 29, 2015

Planets of the Morning

This is a wonderful image and is a highlight for anyone that is able to rise as the sun nears the horizon int he morning. While Jupiter is by far the largest planet in the Solar System it is surprising...

/ November 27, 2015

Aurora over Clouds

Auroras usually occur high above the clouds. The auroral glow is created when fast-moving particles ejected from the Sun impact the Earth’s magnetosphere, from which charged particles spiral along the Earth’s magnetic field to strike atoms and molecules high in...

/ November 25, 2015