Category Archives: atmosphere

atmosphere, atmospheric science

Cloud Watching

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Eyeing Noctilucent Clouds

Noctilucent clouds seen over Blair, Nebraska. Image by Mike Hollingshead, as seen on Spaceweather.com. Go on over there for more gorgeous images. Click to embiggen.
Noctilucent clouds seen over Blair, Nebraska. Image by Mike Hollingshead, as seen on Spaceweather.com. Go on over there for more gorgeous images. Click to embiggen.

Folks lucky enough to be outside the past night or two in parts of North America and Europe have been treated to fine displays of noctilucent clouds.  These are ghostly looking clouds that seem to glow in the sky long after the Sun has gone down. People in northerly latitudes see them quite often, but it has been rare to see them as far south as France, for example, and certainly very rarely over southern Nevada and other mid-latitude locales.

Noctilucent means “night-shining” and nobody’s quite sure exactly what causes these glowing apparitions. They first appeared about the time of the eruption of Krakatoa in the 1885, and they are likely related to the distribution of fine dust in the upper atmosphere. But, where that dust comes from (it’s tough to waft dust from volcanoes UP to where these clouds form) is still a topic of great discussion among atmospheric scientists. It’s possible that dust from space is involved in some way.  The clouds themselves are made of water ice crystals that have formed around tiny particles of dust. They seem to be occurring more frequently now, over wider ranges of latitude. It’s very possible that their spread is related to global warming — also a topic under a lot of discussion these days.

Want to know more about these clouds?  Go here and here to read about what some atmospheric scientists have to say about noctilucent clouds. And, by all means, go outside tonight (and maybe the next few nights) and keep an eye out for glowing, wispy clouds like the ones in the picture above.

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Thanks to everyone who has written to wish us well during our recent move back to Colorado.  We’ve made it in fine shape and are settling in nicely.  It’s good to be back online and sharing science with y’all!

atmosphere, climate change, Earth, global warming

Earth is Where It’s At

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And It’s All We Have… For Now

https://i0.wp.com/nssdc.gsfc.nasa.gov/image/planetary/earth/gal_east-pacific.jpg?resize=474%2C356

Sooner or later, everybody who is interested in space and astronomy gets a look at our planet from “the outside.”  This image, from the Galileo spacecraft during one of its swings around Earth, tells a pretty remarkable story. If you were an incoming alien vessel, you’d see evidence of water. The oceans tell that story, but so do the clouds because they’re made of water vapor. The land masses would tell you that there are places to land on this planet, but at this distance and resolution, you wouldn’t be able to make out plants and animals… or humans and their cities.

If your alien ship had special sensors, it could use spectral analysis to dissect the gases in the atmosphere that blankets the planet. You would find oxygen, nitrogen, plus trace amounts of other gases.  Oh, and carbon dioxide. That’s a biggie. Carbon dioxide (you sometimes see it as CO2) is a by-product of living and geological processed. And, it’s the principal component of the greenhouse gases that we are pumping into our atmosphere from energy generation (driving cars, making electricity, powering manufacturing, etc.). The more greenhouse gases we load into the atmosphere, the warmer our climate is getting. And this is having an effect that future spacecraft will see (and we will have to live with).

As you can see from this picture, our atmosphere looks pretty thin when compared to the vastness of space and the size of our own planet. In fact, if you look at other planetary atmospheres in the solar system, you find them to be thick and heavy (Venus, the gas giants), or thin and possibly even fragile (Mars, Earth, some of the smaller moons of the outer solar system). What we learn about atmospheres is important, since our own planet has the only one that we know of that has harbored (and possibly even helped begin) life.  That makes what we’re doing to it with carbon dioxide a pretty major “experiment.”