Showing posts with label Sky. Show all posts
Showing posts with label Sky. Show all posts

Wednesday, February 25, 2015

Aurora and Milky Way in a Little Sky

Aurora and Milky Way in a Little Sky: APOD: 2014 October 3 - Aurora and Milky Way in a Little Sky


Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2014 October 3


See Explanation. Clicking on the picture will download the highest resolution version available.
Explanation: Stepping stones seem to lead to the Milky Way as it stretches across this little sky. Of course, the scene is really the northern hemisphere's autumnal equinox night. Water and sky are inverted by a top to bottom, around the horizon stereographic projection centered on the zenith above Lake Storsjön in Jämtland, Sweden. In the north the Milky Way arcs from east to west overhead as fall begins, but the season is also a good time for viewing aurora. Geomagnetic storms increase in frequency near the equinox and produce remarkable displays of northern lights at high latitudes, like the eerie greenish glow reflected in this watery cosmos.

Sunday, February 22, 2015

An Evening Sky Conjunction

An Evening Sky Conjunction: APOD: 2015 February 20 - An Evening Sky Conjunction


Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2015 February 20



See Explanation. Clicking on the picture will download the highest resolution version available.
Explanation: Eight years ago, an evening sky held this lovely pairing of a young crescent Moon and brilliant Venus. Seen near the western horizon, the close conjunction and its wintry reflection were captured from Bolu, Turkey, planet Earth on February 19, 2007. In the 8 Earth years since this photograph was taken Venus has orbited the Sun almost exactly 13 times, so the Sun and Venus have now returned to the same the configuration in Earth's sky. And since every 8 years the Moon also nearly repeats its phases for a given time of year, a very similar crescent Moon-Venus conjunction will again appear in planet Earth's evening skies tonight. But the February 20, 2015 version of the conjunction will also include planet Mars. Much fainter Mars will wander even closer to Venus by the evening of February 21.