A imagem do dia 27-01-2014

 
From the Northern to the Southern Cross
Image Credit & Copyright: Nicholas Buer

Explanation: There is a road that connects the Northern to the Southern Cross but you have to be at the right place and time to see it. The road, as pictured above, is actually the central band of our Milky Way Galaxy; the right place, in this case, is dark Laguna Cejar in Salar de Atacama of Northern Chile; and the right time was in early October, just after sunset. Many sky wonders were captured then, including the bright Moon, inside the Milky Way arch; Venus, just above the Moon; Saturn and Mercury, just below the Moon; the Large and Small Magellanic Clouds satellite galaxies, on the far left; red airglow near the horizon on the image left; and the lights of small towns at several locations across the horizon. One might guess that composing this 30-image panorama would have been a serene experience, but for that one would have required earplugs to ignore the continued brays of wild donkeys.

A imagem do dia 27-01-2014

Sunspot Loops in Ultraviolet
Image Credit: TRACE Project, NASA

Explanation: It was a quiet day on the Sun. The above image shows, however, that even during off days the Sun's surface is a busy place. Shown in ultraviolet light, the relatively cool dark regions have temperatures of thousands of degrees Celsius. Large sunspot group AR 9169 from the last solar cycle is visible as the bright area near the horizon. The bright glowing gas flowing around the sunspots has a temperature of over one million degrees Celsius. The reason for the high temperatures is unknown but thought to be related to the rapidly changing magnetic field loops that channel solar plasma. Large sunspot group AR 9169 moved across the Sun during 2000 September and decayed in a few weeks.