1. The Orion Nebula is arguably the finest of all nebulae within the Milky Way visible from the Northern Hemisphere. With a gaseous repository of 10,000 suns, and illuminated by a cluster of hot young stars, the clouds of Messier 42 — as it is also known — glow with fantastic colors and shapes, giving us a bird’s eye view of one of the greatest star forming nurseries in our part of the Milky Way. Messier 42 is a complex of glowing gas, mostly hydrogen but also helium, carbon, nitrogen, and oxygen in decreasing amounts, located 1,500 light-years away. At its very heart, we find the Trapezium, a group of four very hot stars that illuminate the nebula. They are the brightest of an extended cluster of several thousand young stars many of which lie unseen within the opaque gas and dust. Amazingly, whilst the Orion Nebula is easy to identify with the unaided eye, there is apparently no written record of its existence before the 17th century. This image is based on data acquired with the 1.5 m Danish telescope at the ESO La Silla Observatory in Chile, through three filters (B: 60 s, V: 30 s, R: 21 s). East is at the upper right corner and North is at the lower right. Credit: ESO/IDA/Danish 1.5 m/R.Gendler, J.-E. Ovaldsen, and A. Hornstrup.

2. This photo was taken on the plain of Castelluccio by Maurizio Pignotti. Shooting data: 12 shots with Canon 5d old - sigma 12/24 - ISO 800 to 470 Second Heaven - 30 seconds static subject - Star Tracker DIY - tripod - remote control. Double exposure. Credit: Maurizio Pignotti.

3. A prominence is a large, bright feature extending outward from the Sun’s surface, often in a loop shape. Prominences are anchored to the Sun’s surface in the photosphere, and extend outwards into the Sun’s corona. While the corona consists of extremely hot ionized gases, known as plasma, which do not emit much visible light, prominences contain much cooler plasma, similar in composition to that of the chromosphere. A prominence forms over timescales of about a day, and stable prominences may persist in the corona for several months. Credit: Alan Friedman