Tycho Brahe observing the 1572 supernova, with astonished
spectators.

Ever seen one of those? I won't say UFO, because that immediately conjures images of flying saucers and big-eyed space aliens, and that's not what I’m going for here. What I mean is, have you ever seen something in the night sky that you have "never seen before," but that you later learned was actually a natural and recurring apparition, like the appearance of Venus as the Evening Star?

This time of year usually stirs up a phone call or email or two involving "first time" sightings of the bright star Sirius, whose brilliant, multi-colored twinkling catches some people's attention at least once in their lives, causing them to gawk and either wonder why they'd never noticed it before, or assume it's a new thing in the sky, some rare and unusual occurrence.

Sirius did the same thing to me when I was in Junior High. I walked outside one night, looked up, and saw this glittering spectral jewel, brighter than I could remember any star I'd seen. This hook, or teaser, inevitably led me into the adventure of star gazing, because I had to find out what that thing was. But this kind of "revelation" can happen to people much later in life– and in hind sight I'm amazed I hadn't noticed it when I was even younger.

For the past few months, Venus has been in the western sky as the Evening Star– so naturally I’ve been getting more calls than usual. A man who I would guess (by his voice) was past middle age called to report the brilliant white light in the western evening sky, and was stunned to find out it was Venus. I could hear the amazement in his voice that he had never before noticed Venus in his life, after I told him that Venus comes and goes, alternately from the evening and morning skies, but comes back regularly.

And finally I've reached the "point" of this blog: how we can go through sometimes decades of our lives without noticing, or fully registering, something of unusual beauty that has more or less been "in plain sight" all along (or periodically, at least).

My feeling is that is must have a little to do with timing, a little to do with prevailing conditions in our lives, and a lot to do with how we focus our attention on the world around us, or above us. One day we might look to the evening sky and see brilliant Venus flashing over the horizon and not see anything unusual; twenty years later we might look at essentially the same scene and all of our attention and wonder is suddenly drawn to that inexplicably bright light.

See what you think. Go outside one evening in March, look to the south and see if you can spot Sirius– it'll be to the left of Orion's Belt, if you can find that. And, if you're reading this anytime before, say, March 20th, look to the west after sunset and look for Venus. Maybe you've seen these objects before, and know exactly what I'm talking about. Or, maybe, you'll experience something for the first time in your life. Worth a try, isn't it?

37.7631 -122.409

Artist concept of lightning on Venus. Credit: NASA

With all the attention that the exploration of certain other planets has received lately, I feel that Venus exploration has fallen off our radar a bit, and that it is high time for an update.

There is no lack of exploration of Venus today: NASA's MESSENGER spacecraft, bound for Mercury, flew by Venus twice (2006, 2007), making observations on the fly; Japan is currently planning to send a climate orbiter mission ("Planet C") there in 2010; and the European BepiColombo will perform a couple of Venus flybys of its own, in 2013, on its way to Mercury.

Most notably, the European Venus Express orbiter is in the middle of a two-year mission of exploration, and has revealed new and fascinating things about Venus–a planet whose cloud-shrouded surface kept us mostly ignorant about it until recent decades. (Before the 1960's it was even speculated that Venus might be a steamy swamp or rain forest world!)

Here's a quick recap of some of the highlights of Venus Express's findings:

"Hurricanes" at the poles: Venus Express's VIRTIS instrument, which is able to probe several different layers of the atmosphere, has put together a detailed picture of wind behavior at different latitudes and different altitudes. What was discovered from these observations is that Venus has giant, hurricane-like vortexes capping its poles. Winds within these systems all flow in generally the same direction, as you'd expect with hurricanes, circling mostly windless "eyes" at their centers at the poles.

Lighting: Evidence of lightning on Venus was detected by earlier orbiter and lander missions, and Venus Express has confirmed it–maybe more lightning activity than on Earth. What makes Venus's lightning unique among the planets with lightning (Earth, Jupiter, and Saturn, as far as we know) is that it's the only case where lightning is formed by something other than clouds of water droplets–in Venus's case, sulfuric acid droplets do the trick. Lightning can be an important factor in that it breaks up atmospheric molecules and allows them to recombine in different forms.

Active volcano search: It has long been suggested that there may be active volcanoes on Venus today, though no direct evidence (like images of erupting volcanoes, for example) have yet been obtained. Venus Express has measured large variations over time in the concentrations of sulfur dioxide in Venus's atmosphere–a compound that on Earth comes from volcanic eruptions.

There's a lot more to say about Venus, as it is a world as varied and fascinating as the Earth (minus the life forms, as far as we know). Though it may not be the hottest vacation spot in the solar system, with its pressure cooker of a toxic, acid-laced atmosphere, it is one of those great mysteries that we actually get to watch unfold before us as exploration of it moves forward.

37.8148 -122.178

Venus Landing. Credit:
Soviet Planetary Exploration ProgramIt's time to get back to some of the reader’s questions. Over the last couple of months I've focused on the easy ones like "how big is the universe?". Now, people are asking the tough ones, like that from Mike:

"There’s been a recent debate in our local papers regarding Venus' high planetary temperature being related to the dearth of carbon dioxide on the planet. Apparently Venus is much, much hotter than Mercury, even though Venus is twice as far from the sun. Could you explain a bit about our system’s planets and how they differ compositionally? What is it about the Earth's composition of elements that makes it just right for 99% of the life on the planet? I say 99% because it seems 1% of the life is strange enough to exist in all sorts of harsh conditions."

When it comes to the landscape of our own neighborhood, it gets a little more complicated for me. I have a tendency to look right past the solar system in my research of the distant Universe. I'm sure there's an explanation for this in the cliché of missing the forest for the trees. I just do it in reverse.

The Trees

Hubble Deep Field. Credit:
R. Williams, The HDF Team (STScI), NASATruth is, the trees are quite intriguing in their own right. I think people are more impressed with the observations of our solar system because the proximity lends to very detailed images and observations. Compare an image of the surface of Venus to one of the deepest images from Hubble Space Telescope. The image of Venus fits within our sense of scale that we established in our time here on Earth. You can even see familiar rocks and the feet of the Soviet robot. The Hubble Deep Field… needs a bit of explanation.

For the rest of the year, I am going to pull back from the farthest reaches of the universe and focus on Venus and the other planets. It will give me a chance to learn a little about what the Solar System actually looks like. It will also give me a chance to explore some of the most breath-taking images that NASA has created. I'm just going to have to do a little research to get it right.

Kyle S. Dawson is engaged in post-doctorate studies of distant supernovae and development of a proposed space-based telescope at Lawrence Berkeley National Laboratory.

latitude: 37.6797, longitude: -121.698