Cloud Streets in the Bering Sea

Ice, wind, cold temperatures and ocean waters combined to created dramatic cloud formations over the Bering Sea in late January, 2015. The Moderate Resolution Imaging Spectroradiometer (MODIS) aboard NASA's Aqua satellite passed over the region and captured this true-color image on Jan. 23. The frozen tundra of Russia lies in the northwest of the image, and snow-covered Alaska lies in the northeast. Sea ice extends from the land well into the Bering Sea. Over the dark water bright white clouds line in up close, parallel rows. These formations are known as “cloud streets”. Air blowing over the cold, snowy land and then over ice becomes both cold and dry. When the air then moves over relatively warmer and much moister water and lead to the development of parallel cylinders of spinning air. On the upper edge of these cylinders of air, where the air is rising, small clouds form. Where air is descending, the skies are clear. This clear/cloudy pattern, formed in parallel rows, gives the impression of streets. The clouds begin over the sea ice, but they primarily hang over open ocean. The streets are neat and in tight rows closest to land, while further over the Bering Sea the pattern widens and begins to become more random. The rows of clouds are also not perfectly straight, but tend to curve. The strength and direction of the wind helps create these features: where the wind is strongest, nearest to shore, the clouds line up most neatly. The clouds align with the wind direction, so the direction of the streets gives strong clues to prevailing wind direction. Image Credit: NASA/Jeff Schmaltz, MODIS Land Rapid Response Team, NASA GSFC via NASA http://ift.tt/1z6p62x

FAA Commercial Space Transportation Conference

Registration still open for the 18th Annual FAA Commercial Space Transportation Conference, set to take place this week (Feb. 4-5) at the National Housing Center in Washington, D.C. The conference will address the latest in U.S. commercial launch activities, human...



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Winter Issue of The Planetary Report is Here!

The winter issue of The Planetary Report continues to hit Planetary Society members’ mailboxes and, for those of you who want your copy in digital form, it’s now posted on our website.



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Our Planet Has the Vapors

I’ve posted a lot of images of our planet as seen from space, but I wonder if you’ve ever seen it quite like this: in the thermal infrared, where water vapor glows by day and night.

First to orient you, here are visible light images of the Earth from the same satellites, so you can see where they’re pointed:

The satellite GOES-15 (also called GOES West) view is on the left, and GOES-13 (East) is on the right. The West view is almost entirely Pacific Ocean, while East mostly shows North and South America.

The video is the same view, but shows the Earth at a wavelength of about 7 microns, ten times redder than what our eyes can see. At that “color”, warm things glow brightly, while cooler objects are dark.

… kinda. That’s part of the picture (literally), but there’s more. Water vapor in the atmosphere is actually opaque to this wavelength, so it prevents the light from the warm Earth to get out into space where the satellites can see it. I know the white parts look like clouds, and that might be where you think they are, but it’s actually the opposite: The clouds (or at least the water vapor in the air) are where it looks dark in the video.

The animation was put together using the GOES images by James Tyrwhitt-Drake, whom you may remember from previous video of the Earth from space, and of the ridiculously cool video of the Sun in ultraviolet. He sent me a note about this, and we discussed these images. He told me something I didn’t know: On the GOES site, they take the data from the satellite and invert them, swapping black for white, so that clouds look white. I’m not sure why, though it may be as simple as us being used to seeing them as white. That’s obvious to me now; the space around the Earth is cold and should look black, but in the GOES images on their server it’s white.

Tyrwhitt-Drake took the images and re-inverted them, so space (and anything else that’s cold) looks black. That makes it harder to interpret by eye, but it better represents what the Earth would actually look like if you could see it from space in the thermal IR.

Very — puts on sunglasses — cool.

He also pointed out something pretty neat: Keep your eyes on the west coast of South America in the satellite view on the right. You’ll see it pulsing white, about once per second; that’s the Atacama Desert, and you’re most likely seeing it heating up every day as the Sun hits it, causing it to glow in the IR. Deserts are very dry (by definition) so they cool off rapidly at night as well. By the way, right after that bright pulse, you can see the rest of South America get dark as clouds form over land.

It’s interesting that you have to go looking for differences between day and night in the video; it’s not as obvious as it would be in visible light.

Incidentally, water vapor is a pretty good greenhouse gas, even more efficient than carbon dioxide. CO₂ is more worrisome because every year there’s an extra 40 billion tons of it in the atmosphere, pumped there by humans. Water vapor is relatively stable over time. But this video makes it clear—irony!—why water vapor traps heat as well: It’s literally opaque to it. The ground warms up during the day, but the water in our air (as well as CO₂ and other gases) absorbs it, preventing it from radiating away in space.

The result? Well, you know what the result is. Unless you’re a Republican Senator, of course.

Our world is an amazing and intricate machine, and a lot of its delicate parts can’t be seen unless you get away from the planet itself, and look back with different eyes. Their effects are certainly felt, but it’s because we’ve left this planet that we can see it so much more clearly.

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NGC 4676: When Mice Collide

These two mighty galaxies are pulling each other apart. Known as the "Mice" because they have such long tails, each spiral galaxy has likely already passed through the other. The long tails are created by the relative difference between gravitational pulls on the near and far parts of each galaxy. Because the distances are so large, the cosmic interaction takes place in slow motion -- over hundreds of millions of years. NGC 4676 lies about 300 million light-years away toward the constellation of Bernice's Hair (Coma Berenices) and are likely members of the Coma Cluster of Galaxies. The above picture was taken with the Hubble Space Telescope's Advanced Camera for Surveys in 2002. These galactic mice will probably collide again and again over the next billion years until they coalesce to form a single galaxy. via NASA http://ift.tt/1AdFlgg

Super View of Glendale and Phoenix

One of the Expedition 35 crew members on the International Space Station used a still camera with a 400 millimeter lens to record this nocturnal image of the Phoenix, Arizona area on March 16, 2013. Like many large urban areas of the central and western United States, the Phoenix metropolitan area is laid out along a regular grid of city blocks and streets. While visible during the day, this grid is most evident at night, when the pattern of street lighting is clearly visible from above -- in the case of this photograph, from the low Earth orbit vantage point of the International Space Station. The urban grid form encourages growth of a city outwards along its borders, by providing optimal access to new real estate. Fueled by the adoption of widespread personal automobile use during the 20th century, the Phoenix metropolitan area today includes 25 other municipalities (many of them largely suburban and residential in character) linked by a network of surface streets and freeways. The image area includes parts of several cities in the metropolitan area including Phoenix proper (right), Glendale (center), and Peoria (left). While the major street grid is oriented north-south, the northwest-southeast oriented Grand Avenue cuts across it at image center. Grand Avenue is a major transportation corridor through the western metropolitan area; the lighting patterns of large industrial and commercial properties are visible along its length. Other brightly lit properties include large shopping centers, strip centers, and gas stations which tend to be located at the intersections of north-south and east-west trending streets. While much of the land area highlighted in this image is urbanized, there are several noticeably dark areas. The Phoenix Mountains at upper right are largely public park and recreational land. To the west (image lower left), agricultural fields provide a sharp contrast to the lit streets of neighboring residential developments. The Salt River channel appears as a dark ribbon within the urban grid at lower right. Image Credit: NASA via NASA http://ift.tt/1wSk6ZU

Illusion of Lights

I am a big fan of Brad Goldpaint’s astrophotography. His images of the night sky are crisp and clear, vivid and astonishing. He also creates amazing time-lapse videos, which I’ve featured on this blog many times.

Now, in Episode 2 of Crash Course Astronomy, “Naked Eye Observations”, I talked about light pollution, and how it’s robbing of us our skies. This is a matter of some importance to me, for obvious reasons. So I was pretty happy when Goldpaint sent me a note saying he’s putting together a new time-lapse feature called “Illusion of Lights: A Journey into the Unseen”, highlighting this issue. He’s put together a trailer, and as expected, it’s gorgeous:

I love watching lenticular clouds in motion, and seeing Crater Lake in Oregon is always a thrill; it’s one of my favorite places on the planet, and Goldpaint has used it before in his photos and videos.

I love the music, too. I’m a sucker for that kind of drumbeat.

Goldpaint’s dedication to this is no small matter. He sent me this description:

In 2013, Brad and Marci left their day jobs and began educating the public about the damaging effects of light pollution. They left the comforts of home to help reconnect people with the simple beauty of the night sky. The couple sold all their possessions to live in a motorhome while traveling throughout the Western United States, teaching photography workshops and gathering footage for their film. Brad spent countless nights traversing in the dark, carrying heavy camera equipment, and braving the dark unseen. Each filmed location presented unique challenges when confronted by lightning storms, dangerous winds, and up-close encounters with bears and other wildlife. They are excited to share with you the release of their first trailer to their independent film, “Illusion of Lights: A Journey into the Unseen.”

Wow. He has more information on his website. I’m pretty excited about this and I can’t wait to see the final product. It look truly amazing.

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