Venus in all Its Glory

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.

The Eye of the Helix

Look Deep

The Helix Nebula as seen by the European Southern Observatory. (Click to embiggify.)
The Helix Nebula as seen by the European Southern Observatory. (Click to embiggify.)

Well this is just stunning.  The Helix Nebula is a planetary nebula that lies about 700 light-years away from us. It’s what’s left over after a star like the Sun goes through its death throes and blows off much of its atmosphere to surrounding space. If you could float through the material to the central portion, you’d pass through shells of gas that were “exhaled” by the star. And, in the center would be the hot remnant of the old star, shining brightly in visible and ultraviolet light.

This image from the European Southern Observatory’s Very Large Telescope is full of detail in the surrounding clouds. For example, you can see little “blobs” of material that astronomers call “cometary knots”  — not because they’re comets (they’re not) but because they seem to have faint tails extending away from central blobs, pointing away from the star.

If you click on the image above you’ll get an enlarged version.  Look carefully at the central section of the nebula — you should be able to see galaxies in there!  The galaxies aren’t IN the nebula — they’re behind it, and the veil of gas is so thin that you can see much more distant objects right through it!

Go explore the eye of the  Helix — it’s gorgeous!  Want more information? Click here for the press release and links to zoom-in animations of the Helix.