Another gem from APOD, which provides this explanation about the satellite Io:

The strangest moon in the Solar System is bright yellow. This picture, an attempt to show how Io would appear in the “true colors” perceptible to the average human eye, was taken in 1999 July by the Galileo spacecraft that orbited Jupiter from 1995 to 2003. Io’s colors derive from sulfur and molten silicate rock. The unusual surface of Io is kept very young by its system of active volcanoes.

The intense tidal gravityJupiter stretches Io and damps wobbles caused by Jupiter’s other Galilean moons. The resulting frictionIo‘s interior, causing molten rock to explode through the surface. Io’s volcanoes are so active that they are effectively turning the whole moon inside out. Some of Io‘s volcanic lava is so hot it glows in the dark.

Io in truecolor via the Galileo telescope

In Greek mythology, Io was a nymph who attracted the eye of Zeus. Turned into a heiffer for her own safety, she was tormented by his jealous wife Hera with a gadfly that pursued her across the ancient world. On the way Io had a close encounter with Prometheus and eventually found happiness in marriage to an Egyptian King.

Tangling with Greek Gods never made for an easy life.

One great thing about the 21st century: humanity can appreciate the cosmos like never before.

Along with increasingly affordable high-powered telescopes, a new artistic field has come into being: astrophotography.

Connecticut-based Robert Gendler is one of the best atsrophotographers in the world; his work has been featured 63 times on NASA’s Astronomy Photo of the Day website.

Gendler’s latest APOD contribution is this succulent image of the Triffid Nebula. Cosmic eye-candy. Enjoy!

The Triffid Nebula; photo by Robert Gendler

Last November I blogged about a jaw-dropping image of the Milky Way by the American photographer Wally Pacholka – see Amazing. He’s developed a stunning way of photographing the night sky that gives a sense of three dimensionality.

According to his website, NASA has now published 34 of Mr Pacholka’s photographs in its Astronomy Picture of the Day series – more than any other photographer.

Today’s APOD – The Milky Way Over Devil’s Tower – is the latest. Devil’s Tower in Wyoming will be familiar to movie goers; it was the scenic backdrop for Stephen Speilberg’s Close Encounters of the Third Kind.

The Milky Way Over Devil's Tower by Wally Pacholka

A thousand parsecs hence, within our own galaxy and appearing in the constellation of Gemini, a spectacular event is in progress.

The Eskimo Nebula

If mainstream astonomical theory is correct, when we look at the Eskimo Nebula we’re witnessing a late stage in the evolution of a star similar to our own sun. As it turns into a superdense white dwarf, the star ejects large amounts of gaseous matter into the surrounding space. The afterglow fades slowly.

This nebula was first catalogued in the late 18th century by the brilliant musician and astronomer William Herschel. Now, with photos from the Hubble telescope, we can observe it’s ghostly magnificence better than ever before.

Greedy, bellicose idiots, scrapping to snatch unfair portions of the spoils of mortal existence, would do well to bookmark NASA’s Astronomy Picture of the Day website and visit often.

We need to turn swords into ploughshares, missile-launchers into telescopes.