Astronomy Picture Of The Day

[mercuryrapids]

21st May, 2010



Explanation: Last weekend, the Moon and Venus formed a beautiful close pair in the west after sunset, a scene enjoyed by skygazers all over the world. In this lovely view of the conjunction from Sweden, a calm lake Vallentuna lies in the foreground with sunset colors still fading behind the treeline on the far shore. The young Moon's sunlit crescent is bright, but its entire outline can be seen by Earthshine, light reflected from planet Earth itself. For well-placed skygazers, on Sunday, May 16 the Moon actually occulted (passed in front of) brilliant Venus. For many, the occultation was visible during daylight hours.

[mercuryrapids]

22nd May, 2010



Explanation: Suspended by magnetic fields above a solar active region this dark filament stretches over 40 earth-diameters. The ominous structure appears to be frozen in time near the Sun's edge, but solar filaments are unstable and often erupt. The detailed scene was captured on May 18 in extreme ultraviolet light by cameras on board the Solar Dynamics Observatory. While the cooler plasma of the filament looks dark, hotter, brighter plasma below traces magnetic field lines emerging from the active region. When seen arcing above the edge of the Sun, filaments actually look bright against the dark background of space and are called prominences.

[mercuryrapids]

23rd May, 2010



Explanation: That's no sunspot. On the upper right of the above image of the Sun, the dark patches are actually the International Space Station (ISS) and the Space Shuttle Atlantis on mission STS-132. In the past, many skygazers have spotted the space station and space shuttles as bright stars gliding through twilight skies, still glinting in the sunlight while orbiting about 200 kilometers above the Earth's surface. But here, astrophotographer Thierry Lagault accurately computed the occurrence of a rarer opportunity to record the spacefaring combination moving quickly in silhouette across the solar disk. He snapped the above picture on last Sunday on May 16, about 50 minutes before the shuttle docked with the space station. Atlantis was recently launched to the ISS for its last mission before being retired.

[Martin]

The great pictures keep coming. Are you going to run out of them eventually Merc?

[mercuryrapids]

24th May, 2010



Explanation: The clouds surrounding the star system Rho Ophiucus compose one of the closest star forming regions. Rho Ophiucus itself is a binary star system visible in the light-colored region on the image right. The star system, located only 400 light years away, is distinguished by its colorful surroundings, which include a red emission nebula and numerous light and dark brown dust lanes. Near the upper right of the Rho Ophiucus molecular cloud system is the yellow star Antares, while a distant but coincidently-superposed globular cluster of stars, M4, is visible between Antares and the red emission nebula. Near the image bottom lies IC 4592, the Blue Horsehead nebula. The blue glow that surrounds the Blue Horsehead's eye -- and other stars around the image -- is a reflection nebula composed of fine dust. On the above image left is a geometrically angled reflection nebula cataloged as Sharpless 1. Here, the bright star near the dust vortex creates the light of surrounding reflection nebula. Although most of these features are visible through a small telescope pointed toward the constellations of Ophiucus, Scorpius, and Sagittarius, the only way to see the intricate details of the dust swirls, as featured above, is to use a long exposure camera.

[Martin]

Very nice. That part of space reminds me of the Star Tek: TNG episode when the ship is trapped and an Alien starts killing random member of the crew, so Picard starts the self-destruct. It turns out to be an experiement.

[mercuryrapids]

25th May, 2010



Explanation: It's been a long trip for the Martian rover Opportunity. Last week Opportunity surpassed Viking 1 as the longest running mission on Mars, now extending well over six years. Pictured above, Opportunity's tire tracks cross a nearly featureless Martian desert, emanating from a distant horizon. Landing in 2004 in Meridiani Planum, the robotic Opportunity has embarked on its longest and most dangerous trek yet, now aiming to reach large Endeavor Crater sometime next year. Endeavor, it is hoped, holds new clues to the ancient geology of Mars and whether Mars could once have harbored life.

[Martin]

I wonder how long those tracks will stay on the surface?

[mercuryrapids]

26th May, 2010



Explanation: What's happening above the Cotopaxi volcano in Ecuador? Quite a bit, from the looks of the above one-night, time-lapse movie, taken earlier this month. The majestic volcano is first seen through breaks in fast moving clouds as the movie begins. Soon the clouds have dissipated and a sky filled with stars seems to rotate about the snow-peaked volcano's peak. The band of our Milky Way Galaxy, the dark Coal Sack nebula, and the Southern Cross can all be seen overhead. Satellites steak by from several directions. Soon thin clouds roll by and seem to make the brightest stars sparkle. On the volcano (starting at about 1:13 of the movie), the lights of climbers flash. Near the end of the movie, a bright airplane passes over the peak with a residual trail seen drifting away.

[Martin]

Beautiful! That video would be really good with some atmospheric music added.