In the darkness of space we see the part of the Moon that the Sun illuminates. But sometimes there is a bright crescent Moon with a dark shadow filling in the rest of the Moon's face. What lets us see the Moon's night side, and how might the phenomenon detect life on distant worlds?

Earthshine

Saturn is already one of the most beautiful objects in the Solar System. But here is what I think is one of most incredible pictures ever of Saturn. The Cassini spacecraft is behind Saturn as the ringed planet blocks the sunlight from Cassini's view. But you can see the ringshine on the lower half of the dark side of Saturn.

But there's something else almost unique in this image. Look hard at the far left of the picture just above the bright rings to try to find a tiny white dot. (You might need to click on the picture to go to the higher res Wikimedia version.) That is Earth.

I love this photo by Babek Tafreshi. It not only shows a crescent Moon with earthshine but also the beautiful skies of the high Chilean desert. The Paranal Observatory is operated by the European Southern Observatory and includes the Very Large Telescope. (Great telescope, slightly pathetic name.)

This observatory also featured in the film Hidden Universe 3D which I reviewed - it contains some stunning footage.

Leonardo da Vinci was the first person to explain the phenomenon of earthshine. Here is the drawing Leonardo made as part of his explanation.

There is a song called "Earthshine" - it's sung by Rush on the album Vapor Trails.

It begins:
On certain nights
When the angles are right
And the moon is a slender crescent
It's circle shows
In a ghostly glow
Of earthly luminescence

The rest of the lyrics are here.

Here is a stunning photograph of the Moon with earthshine, sometimes known as the "Old Moon in the New Moon's arms". It was taken from Las Campanas Observatory in Chile's Atacama Desert a few nights ago.

Image Credit & Copyright: Yuri Beletsky (Carnegie Las Campanas Observatory, TWAN)

Beautiful.

New moon and Saturn taken early Sunday morning (February 11) by Paul Dawson in Boise, Idaho, USA.