Daily Archives: February 26, 2009

venus, Venus Express

Venus in all Its Glory

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The Evening Star

Dont miss the final Moon-Venus conjunction of this seasons cycle. Theyll be a real eye-catcher at dusk on Friday the 27th, at least if youre in the longitudes of the Americas. These scenes are always drawn for the roughly middle of North America (latitude 40° north, longitude 90 ° west). European observers: move each Moon symbol a quarter of the way toward the one for the previous date. In the Far East, move the Moons halfway. The blue 10° scale is about the size of your fist held at arms length. For clarity, the Moon is shown three times actual size. (Click to embiggen)
Don't miss the final Moon-Venus conjunction of this season's cycle. They'll be a real eye-catcher at dusk on Friday the 27th, at least if you're in the longitudes of the Americas. These scenes are always drawn for the roughly middle of North America (latitude 40° north, longitude 90 ° west). European observers: move each Moon symbol a quarter of the way toward the one for the previous date. In the Far East, move the Moons halfway. The blue 10° scale is about the size of your fist held at arm's length. For clarity, the Moon is shown three times actual size. (Click to embiggen) (Courtesy SkyandTelescope.com)

We went out last night for dinner and on the way to the restaurant we noticed Venus shining high in the west. It’s really gorgeous these nights.  If you  haven’t been out lately, take  a step out and look west after sunset.  It’s absolutely stunning, shining like a jewel up there. You can’t miss it.

Over at BadAstronomy, Phil Plait has a nice entry called Beauty Without Borders, an effort to get people around the world watching Venus. There’s a website about it, called BeautyWithout Borders: an Evening for Venus.

The event started last night and will go through March 1, so strap on your Venus-viewing eyes, step outside somewhere with a good view to the west and join millions of people around the world who are feasting their eyes on planet Venus.

While we’re all on the ground watching the Evening Star, the European Space Agency has been studying Venus with the Venus Express spacecraft.  Lately the mission folks have been studying up on an eerie infrared glow in the nighttime atmosphere of Venus. That glow occurs in the presence of nitric oxide and its presence is giving scientists a good view into the temperamental atmosphere of the planet — its chemistry and composition, as well as atmospheric  temperatures and wind directions.

The nightglow is ultimately caused by the Sun’s ultraviolet light as it encounters the atmosphere and breaks the molecules up into atoms and other simpler molecules. The free atoms may recombine again and, in specific cases, the resulting molecule is charged up with some extra energy that it radiates as infrared light.

The night glow on Venus has been seen at infrared wavelengths before, giving away the presence of oxygen molecules and the hydroxyl radical, but this is the first detection of nitric oxide at those wavelengths from an area of the atmosphere that lies above the cloud tops at around 70 kilometers above the surface. The oxygen and hydroxyl emissions come from 90-100 kilometers altitude, whereas the nitric oxide comes from 110-120 kilometers altitude.

Want to read more about this cool find?  The ESA folks have a whole web page up about Venus’s atmosphere. Check it out!

And don’t forget to go study Venus with your own Mark I eyeball set. This week we’ll be seeing the last Moon-Venus conjunction for a while in our evening skies over the  next few days.  Read more about what’s up tonight at SkyandTelescope.com.