In case you were wondering what the snow was like here in Colorado the other day…

[Click to ensnowflakenate.]

That’s an image taken by NASA’s Aqua satellite on February 5, 2012. I live in Boulder, to the northwest of Denver (which is labeled), right on the edge of the Rockies. We got well over 30 cm here locally, and it was deeper in other places. Typical of the area, though, the Sun was out the next day, and now our yard looks like a fairyland of sparkles.

It’s unusual to get a heavy snowfall like this in February (we do get big ones, but later in the year) and from what I’ve heard this was a record for a February. And not to overextend the post to climate change, but a) weather is not climate… unless you add time, and 2) contrary to any soundbite you might hear, snowstorms will actually become more common as the Earth warms. Warmer weather means more evaporation, so more moisture in the air. It’s still cold higher up in the atmosphere, and it’s still cold in the winter over land, so a warmer planet overall means more snow in some places. I’m not attributing this event to global warming, to be clear. But it’s the kind of thing we can expect in the coming years.

NASA image courtesy Jeff Schmaltz, LANCE/EOSDIS MODIS Rapid Response Team at NASA GSFC

- Snowpocalypse 2011 from space!
- Lovely, frigid ripples
- Icy swirls around a patient volcano

Recently, a picture of the New England area of the US photographed by astronauts on the ISS made the rounds. It was lovely, and inspired Rémi Boucher and Guillaume Poulin, two scientific communicators at an astronomy center in southern Quebec called the ASTROLab, to see if more pictures were taken. At The Gateway to Astronaut Photography of Earth they found hundreds of photos taken from that pass, so they put them together into a wonderful time lapse video of the journey:

The video starts as the space station is over the Gulf of Mexico. The path of the station took it just east of the US coastline, and this view looks generally to the northwest. You can see Florida clearly, as well as Atlanta (surprisingly far to the west), the gigantic DC-Baltimore-Philadelphia-New York City corridor, then New England. Cape Cod is such an obvious landmark! Finally we can see southeastern Canada, and the Atlantic ocean.

I love how the northern lights are subtle, just hinted at, during much of the video since they are seen from such a great distance and edge-on, only to get brighter and stronger with proximity.

One thing that’s a bit puzzling: what are the lights seen in the Gulf of Mexico at the beginning of the video? My first guess would be oil rigs — there are quite a few of them. If anyone knows for sure, leave a comment!

I’ll note that this video felt much smoother to me than others of its kind. It’s displayed at 30 frames per second, but slowed down to half speed on top of that, which is probably what helps give it such a smooth, velvety feel. The entire elapsed amount of real time is only about 10 minutes — which is a powerful reminder of just how fast 8 km/sec (5 miles/sec) really is.

Credit: Image Science and Analysis Laboratory, NASA-Johnson Space Center. "The Gateway to Astronaut Photography of Earth."; Rémi Boucher – Guillaume Poulin / ASTROLab du parc national du Mont-Mégantic

Cerro Paranal, in the high, dry, Atacama desert in Chile, is where some of the best astronomy in the world is done. It’s graced with incredibly dark and steady skies, and a view of the southern hemisphere skies that, frankly, makes me jealous.

So it’s hard to argue with the title of this short time lapse video, An Astronomer’s Paradise:

This was taken by photographer Babak Tafreshi, who alerted me that he had put it online. Watch it to 1:30 in if only to watch Orion rise — upside down, to my northern hemisphere bias! — with colors and texture that are simply stunning.

Isn’t that awesome? And then a few seconds later, he shows a still image of the great Carina Nebula with the four domes of the Very Large Telescope Interferometer silhouetted against the sky. You can get a better look at that at The World At Night website, which has amazing shots of the sky.

I hope someday to make a trip to this part of the world. To see this for myself…

Credit: Babak Tafreshi

This is so cool: NASA’s twin GRAIL spacecraft (now named Ebb and Flow) have cameras on board to take images of the lunar surface, and an animation has been put together of Ebb’s view of the Moon’s far side!

Pretty neat. I love the wide-angle view; the individual images were taken while Ebb was still over a thousand kilometers from the Moon. The huge circular feature you can see on the right 30 seconds into the video is Orientale Basin, an impact so huge it must’ve lit up the solar system a few billion years ago. That basin is nearly 1000 km (600 miles) across! See the LRO image below for a clearer view, and click it for more info.

I’m really looking forward to seeing what will be done with these cameras. As Principal Investigator Maria Zuber explains in the video, they were installed specifically for educational purposes, and kids all over America will get a chance to examine the data. I love this idea, since it means these children will be invested in the project itself, and remember it for their whole lives. It’s a fantastic idea.

Image credit: NASA/GSFC/Arizona State University

There is just something wonderful when Hubble points to nearby spiral galaxies. Sprawling and detailed, we get both great resolution on smaller features as well as a jaw-dropping overview of a grand spiral… like, say, NGC 1073:

Yeah, I know. [Click to galactinate -- I had to shrink it to fit here, and it lost a lot of the coolness when I did -- or grab the 3900 x 3000 pixel version.]

NGC 1073 is a decent-sized spiral galaxy about 60 million light years away. It’s actually part of a small, tight group of galaxies many of which are far more famous (like NGC 1068). But 1073 is important because of a simple property: it looks like us.

While it’s not a perfect match, NGC 1073 does bear an interesting resemblance to our Milky Way galaxy (UGC 12158 looks more like our galaxy, but is far bigger, for example). Both have large, rectangular bars going across their centers. Bars are a bit odd, since you’d expect the arms just to wind all the way down to the center. But the gravity of a galaxy isn’t like the gravity of a solar system, with a big heavy star sitting in the center. Galaxies have their mass spread out over a long distance, so what gas and dust clouds and stars feel in the way of gravity is different, and bars are a natural outcome of that. However, they’re still not perfectly understood. Bars may form when galaxies collide, and they might be an indication of a galaxy reaching middle age. Perhaps there are other factors as well.

Studying galaxies like NGC 1073 will help us understand how bars form, and why we have one too. Remember, we’re stuck inside our galaxy and can’t see it from the outside (that picture above is an illustration based on detailed observations). It really helps our understanding of the Milky Way to observe galaxies like ours.

An important thing too is that the two galaxies are different in some ways: NGC 1073 has more open arms, for example, compared to our more tightly wound arms. Those differences are telling us something as well. What is it that makes one galaxy hold its arms closer in, and another to fling them out? Why does this galaxy have two arms, and that one three? If you can look at two galaxies that are alike except in one way, it’s easier to isolate the cause. So studying NGC 1073 is a great way to study ourselves.

It always makes me think of Nietzsche, who wrote on the nature of man, "And when you gaze long into an abyss, the abyss also gazes into you."

But on the nature of the Universe, it changes: "And when you gaze long into an abyss, your gaze falls back on yourself."

Last week, I posted an exceptional image of our home world as seen by the Suomi NPP Earth-observing satellite. The image was so popular that NASA released a second one, this time of the Eastern hemisphere, showing once again why it’s called the Blue Marble:

[Click to engaiaenate, or grab the terrestrialicious 11,500 x 11,500 pixel shot].

Like the other one, this is a mosaic, created over six different orbits — the bright north/south swaths are actually the reflection of the Sun in the ocean as the satellite passed over that area multiple times.

Although the satellite is in low Earth orbit, just a few hundred kilometers off the surface, the images have been mosaicked together to represent the view as if you were about 13,000 km (8000 miles) away. You’re seeing most of but not quite all of the entire hemisphere here. The inset image shows why; the farther you are from Earth the more of it you see.

If you’re having a hard time picturing that, imagine taking a camera and holding it a couple of centimeters from your floor. You only see a small section of the floor, right? Now take hundreds of pictures, moving the camera each time to get a different part of the floor. If you stitch those pictures together you have a complete image of your floor, even though it was too big to see from any individual shot. It’s as if you were hovering over the floor from higher up and took one shot.

That’s how this was done as well, though the pictures couldn’t just be stitched together; they had to be warped a bit to account for the Earth being round (near the Earth’s limb you’re seeing the ground at more of an angle than what’s directly below you). That’s why the image gives you such an overwhelming feeling of perspective, of actually being over the planet from all those thousands of kilometers away.

And I wonder… someday, our children may get this view every day, just by looking out a window. Every time I think about that, I get a chill. When I was a kid, that thought was science fiction. Now it’s maybe just a few more years down the road.

[UPDATE: Right after posting this, I got a feeling of deja-vu, and suddenly realized where I've seen this view of the Earth before: Apollo 17. What I wrote in that last paragraph is literally true: humans have seen this view before, and I hope that one day it will be routine to see it this way once again.]

Image credit: NASA/NOAA.

Thanks to astronaut Ron Garan on Google+, I was alerted to some amazing footage of the Moon setting as seen by astronauts on board the International Space Station. I uploaded it to YouTube and added some comments to show you something really cool…

[Set it to high-def and make it full screen!]

Astonishing, isn’t it? As the Moon sets, you’re seeing it through thicker and thicker air. The air acts like a lens, bending the light upward. The part of the Moon nearer the Earth’s limb gets bent up more, so the Moon looks like it’s getting flattened. Watch it again; the top of the Moon doesn’t appear to be affected much. It looks more like the bottom slows down and the top pushes into it. You can read about this effect in more detail in an earlier blog post.

Weirdly, as I watched the video, it looked very much like the whole Moon was shrinking as it set, as if it were receding rapidly. When I saw that I knew intuitively that couldn’t be real; the ISS is only moving a few thousand kilometers over the time this whole video was taken (about ten minutes), not nearly enough to see that big a change in the size of the Moon. It’s 400,000 kilometers away, after all! So I measured the size of the Moon on the screen, and incredibly the width doesn’t change. Do you see it appear to shrink too? It’s an illusion!

Funny how our brain interprets such things. As if seeing a gigantic rock moving through the sky while perched on board a football-field sized satellite moving at 30,000 km/hr isn’t weird enough!

Credit: Image Science and Analysis Laboratory, NASA-Johnson Space Center. "The Gateway to Astronaut Photography of Earth".