Category Archives: Venus Express

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.

Earth, exoplanets, planets, Venus Express

But is it Intelligent Life?

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Venus Express Looks for Earth Life

In all the excitement about planetariums and U.S. politics (and the insanity that is ensuing), poor little Venus Express hasn’t been getting much attention. This is a mission launched by the European Space Agency to study our neighboring planet. It’s loaded with cameras and heat-sensing spectrometers and other instruments so that it can tell us more about that cloud-shrouded world. Well, as it turns out, those instruments can also look at Earth as if it were an alien planet and figure out if it’s habitable.

Yes, indeed folks, we DO KNOW there IS life on Earth. We know it because we’re here. Live evolved here on Earth beginning some 3.8 billion (or perhaps earlier) years ago, spurred by a mix of chemical elements leftover from the formation of the Sun and planets. Some of that “life stuff” was created inside other stars that died long before our solar system existed. It’s a cosmic thang! But, all that’s in the past. Venus Express is looking at Earth now and helping us ask some kind of importan questions, like “What do life signatures look like on a planet?”

Images of Earth (top) and spectra showing the signatures of water and oxygen in our atmosphere, as seen by Venus Express
Images of Earth (top, from NASA's solar system simulator) and spectra showing the signatures of water and oxygen in our atmosphere, as seen by Venus Express and its VIRTIS system. It took these spectra between April and August 2007. Courtesy ESA/VIRTIS/NAF-IASF/Obs. de Paris-LESIA.

Here on Earth, there’s life ranging from microbes to us monkey-types, and at each level, it leaves clues to its existence. For example, us humans are putting out huge amounts of carbon dioxide, which can be traced in our atmosphere.

Plants, on the other hand, are bright in infrared light, and very soon we’ll have detectors able to discern the signatures of plant chlorophyll on our planet (and others). However, the biggest clues about whether our planet can sustain life are the signatures of oxygen and water in our atmosphere, which Venus Express can see quite nicely, thank you very much.

Okay, you think, big deal!  We already knew all that about our planet.

True. But, if you saw those same signatures on another planet, you’d get all excited, wouldn’t you?  Such observations would tell you that the planet is capable of sustaining life that relies on water and oxygen.  If we’re lucky, and using such instruments as Venus Express has, we might even be able to detect stuff like molecules of chlorophyll.

If you keep the instruments aimed at a planet over a long period of time, as Venus Express is doing with Earth, you can also learn things about the weather systems on that planet (because atmospheric changes over time can be mapped), and maybe even something about oceans and glaciers, which have their own unique ways of interacting with the atmosphere.

The amazing thing about the Venus Express observations is that, from its point of view, Earth is less than a pixel wide. It appears as a single dot.  Which is a LOT like how planets around other stars look to us right now. Yet, it was able to get detailed spectra of Earth’s atmosphere and figure out that the conditions for life exist here.

Since we’re on the verge of finding Earth-like planets, astronomers using techniques and instruments similar to those of Venus Express will very likely be able to track down any life-bearing (or life-bearing-capable) worlds.  The one thing we won’t be able to tell about that distant life is whether it’s intelligent or not. That will have to wait until we intercept alien signals and can figure out what they’re saying to each other (and the cosmos). (Let’s hope we don’t get the equivalent of THEIR political debates being broadcast to the neighbors — I’d hate to find out that the Greeblethorax Old Party on 55 Cancri IV also doesn’t like planetariums!)

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