Astronomy4all
Bristlcone Under an Ancient Sky by DanB. on Flickr.
Horsehead Nebula by kappacygni on Flickr.
Comet C/2011 L4 Panstarrs by kappacygni on Flickr.
looking into the center of the Milky Way by write_adam on Flickr.Via Flickr:
To look toward the constellation Sagittarius is to look in the direction of the center of our galaxy.  This region is among the sexiest in the night sky, especially in long exposure photography, with bright nebulae, dark dust and star clusters packed into a thick starfield.
This is a stack of ten 2-minute exposures @ ISO2000, using a Canon 6D and 24-105mm f/4L at f/4 and 24mm. The images were tracked using a Vixen Polarie star tracker on a lightweight carbon fiber tripod.  Taken April 4 2013 from the dark skies of Spanish Wells, Bahamas.

looking into the center of the Milky Way by write_adam on Flickr.

Via Flickr:
To look toward the constellation Sagittarius is to look in the direction of the center of our galaxy. This region is among the sexiest in the night sky, especially in long exposure photography, with bright nebulae, dark dust and star clusters packed into a thick starfield.

This is a stack of ten 2-minute exposures @ ISO2000, using a Canon 6D and 24-105mm f/4L at f/4 and 24mm. The images were tracked using a Vixen Polarie star tracker on a lightweight carbon fiber tripod. Taken April 4 2013 from the dark skies of Spanish Wells, Bahamas.

Falling by Giacomo Gaudenzi on Flickr.
Lost Lake by Ben Canales on Flickr.

Lost Lake by Ben Canales on Flickr.

Aurora Pi π by savillent on Flickr.

Aurora Pi π by savillent on Flickr.

All Things Must Come to an End by Ben Canales on Flickr.