Is there anything more magnificent than a "grand design" spiral galaxy? This is NGC 6118, a gorgeous galaxy 80 million light years away. It's about 100,000 light years across, the same size as the Milky Way. It's not an identical twin; our galaxy is a barred spiral, with a hefty rectangular clump of stars in the center. Still, NGC 6118 is very similar to ours.

It's a fantastic image, but didn't make my Top 14 cut because I liked the M51 image better, and there was more science in the M51 image as well. It was tough; this picture is really spectacular. But sometimes that's not enough to make it to the big leagues.

Get the hi-res version here.

Image credit: ESO

Dione and Rhea are moons of Saturn, and this Cassini spacecraft shot of them makes it look like they're some sort of giant microorganism (macroorganism? Cosmoorganism?) undergoing mitosis.

In reality, Dione (top) is passing in front of Rhea (bottom) from Cassini's viewpoint. There are three coincidences making the pair look like one giant peanut-shaped object: 1) Dione is slightly smaller than Rhea, but closer, so they appear to be the same size in the picture; 2) they have about the same albedo (reflectivity) so shades of the moons match, blending them together better; and 3) there is a giant crater on the south end of Dione that lines up with the point where they overlap, tricking your brain into seeing the junction point as the waist of a peanut.

As much as I love this picture, the one of Rhea on top of Titan was cooler, so that one made it into the Top 14 instead of this.

Get the hi-res version here.

Image credit: NASA/JPL/Space Science Institute

This is one of the youngest known craters on the Moon: it was violently excavated from the lunar surface on April 14, 1970! No one saw it hit, but we know it happened then because we were the ones who made it: it was formed when the upper-stage Saturn V booster from Apollo 13 slammed into the Moon!

This Lunar Reconnaissance Orbiter image has lots of hints to tell us this is where the booster hit: for one, the bright rays extending from the crater - made as dust plumes from the impact settled - indicate how young the hole is; they fade with time. The size of the crater (about 30 meters across) is what's expected from such an event. And of course, the impact point was known.

I almost put this in the Top 14 list, but the LRO shot of the boulder that rolled into the crater tickled me more.

Get the hi-res version here.

Image credit: NASA/GSFC/Arizona State University

Under any other circumstances, this gorgeous high-resolution and lushly-colored image of the Sun's surface would have easily made my Top 14 list, but was edged out by an even more phenomenal shot of our nearest star.

Still, this is a spectacular and eerie shot: taken at a wavelength of light that picks out calcium in the Sun, you can see long ribbons of plasma, bright where they've just risen from below the surface (still hot from being deeper in the Sun) and darker where they are about to sink. You can also see a sunspot on the lower right, looking, ironically, a bit like a sunflower. Bear in mind though that the entire Earth could be engulfed in that spot!

Get the hi-res version here.

Image credit: National Solar Observatory/Dunn Solar Telescope/IBIS/Kevin Reardon

This is not a weather satellite picture: it was taken by the Lunar Reconnaissance Orbiter when it was 400,000 km (240,000 miles) from Earth! It shows the fully-illuminated Earth on August 9, 2010. You can clearly see North and South America, and the cloud patterns are lovely.

I know, it's a grayscale image and not color, but sometimes that makes a picture even more lovely; your eye isn't distracted by the different hues. And I do love shots of our home planet from space.

Get the hi-res version here.

Image Credit: NASA/GSFC/Arizona State University

No picture from the Cassini spacecraft has made me laugh out loud more than this one! It's of the icy moon Enceladus, discovered to have a series of water geysers erupting from its south pole. But the scale, orientation, and slightly-offset nature of this image makes it look like a giant spaceship trying to escape using full throttle on its rockets!

I don't mind a little whimsy in my my Top 14 list, but the Rhea/Titan shot from Cassini was more dramatic, so this science fictional scene of Enceladus is relegated to the Runners-Up.

Get the hi-res version here.

Image credit: NASA/JPL/Space Science Institute

When frozen carbon dioxide - dry ice - is mixed in with sand and rock on Mars, it can disturb the ground around it when it warms up. And that means cliffs on the Red Planet are dangerous places to be in spring time: avalanches like this one are common!

The Mars Reconnaissance Orbiter's HiRISE camera has spotted quite a few of these avalanches, and they're awesome each time. In this event you can see the white plume of dry ice and sand falling down the cliffside, and the huge billowing plume of dust where it hits. Look at it: you're seeing a gigantic landslide caught in the act! And the only reason I didn't pick this one for my Top 14? Because another one made my list in 2008.

Get the hi-res version here.

Image Credit: NASA/JPL/University of Arizona

What world is this? Surprise: it's ours. This snapshot of Earth was taken by the Japanese Akatsuki spacecraft as it headed from our planet to our sister world of Venus. The picture looks odd because it's taken in the infrared, which we're not used to seeing! One of the reasons I love this picture is that it looks an awful lot like the way planets were always shown in "Space:1999", a TV show I loved when I was a kid. Readers of a certain age will understand.

[There is no higher-res version of this, but you can read more about it on Emily Lakdawalla's blog post at The Planetary Society.]

Image credit: ISIS/JAXA

Why is there a giant dart board on Mars?

Technically, this is called a terraced crater. It looks like there was a big impact a long time ago, and then a second one more recently almost dead center in the big one! But appearances can be deceiving, and in fact this crater is a puzzler. In the original post, I wondered if perhaps the terrain explains the weird shape; a second crater to the lower right (not visible in this cropped image, but you can see it in the bigger one) looks very similar to this main crater. But it's not at all clear what's going on here; see my original post for details.

However this weird thing formed, it's a pretty amazing image... but still edged out by the shot of sand dunes and frilly sand-slides in my Top 14 list.

Get the hi-res version here.

Image credit: NASA/JPL/University of Arizona

In early June, 2010, something probably a kilometer across slamed into Jupiter's atmosphere. Ramming through the dense gas at speeds of 80 km/sec, it quickly slowed to a stop, detonating violently as all its vast kinetic energy was converted into a mind-numbing explosion which was the equivalent of a million one-megaton bombs!

Anthony Wesley, an accomplished amateur astronomer in Australia, not only discovered the event (which lasted mere seconds) but also caught it on video and made this color composite image of the titanic detonation. Diminished only by distance, the flash of light you can see to the lower right is the proof of the impact; if something this size were to hit the Earth it would bring terrible devastation to our planet. It would only be a fraction of the dinosaur-killer asteroid impact, but still enough to lay waste to an entire country and have global effects. It might not spell the end of humanity, but all in all I'd rather it didn't happen!

Get the hi-res version here.

Image credit: Anthony Wesley

I've seen galaxies in all shapes: elliptical, spiral, weirdly mashed up, even rings. But NGC 4452 really threw me when I saw it. Sure, spiral galaxies are flat, so when seen on-edge they look a little weird. But this one is so narrow, far more than usual! That really threw me when I first saw it.

One reason the galaxy looks so flat is because one of the two colors of light seen in this image is the near infrared, which tends to downplay dust and gas in the galaxy. Still, the galaxy really is quite flat, even in visible light. It's a remarkable picture, worthy of being among the best of the year, but as with the spiral at the beginning of this Runners-up list, it didn't really compare to the incredible M51 spiral galaxy image, so I left it off.

Get the hi-res version here.

Image credit: ESA/Hubble

Despite decades of space exploration, we've only visited a handful of comets up close. That's because most comets move on orbits that give them a high velocity when they pass the Earth, making a rendezvous difficult. But in 2010, the Deep Impact spacecraft (renamed to EPOXI) flew past the nucleus of the comet Hartley 2 and returned amazingly detailed images.

This shot shows two views from the flyby. On the right you can see one part of the comet's peanut-shaped nucleus, and it's emitting a storm of snow - literally, ice made of water - ranging in size from snowflakes up to snowballs a few centimeters across. On the left is the longer (and in my opinion, more beautiful) view, showing the ice being jetted off the nucleus, as well as the shadow of the nucleus itself on the material it had previously blown off!

As much as I love this image, I couldn't find a high-enough resolution shot of it to warrant putting it in the Top 14 (so I chose a closeup of the asteroid Lutetia instead), but I think you'll agree this is an astonishing view that we very rarely see.

Get the hi-res version here.

Image credit: NASA/JPL-Caltech/UMD

It's not too often a bright star will be positioned close to a nearby galaxy on the sky, but there are a few examples... like HD 106381, a star which is superposed on the edge of the galaxy PGC 39058.

But it's a coincidence: the star is 650 light years away, the galaxy 14 million. It's actually a pretty dinky galaxy; we can see it clearly because that's actually a relatively close distance as galaxies go. The galaxy has millions of stars, but distance takes its toll, and the star appears far, far brighter -- even though in reality the star is not even visible to the naked eye!

Get the hi-res version here.

Image credit: ESA/Hubble

Of all the pictures I went through for my Top 14 list, this was the toughest to leave out, because I think it evokes the most basic of human emotions. It shows astronaut Tracy Caldwell Dyson, team member of Expedition 24, on board the International Space Station. Floating in the cupola, she is wistfully gazing out on the Earth just a day before leaving space to come home once again.

I do so love this picture. It represents so much: homesickness, maybe, and a hint of sadness that her time left on the ISS is drawing to a close. But it also represents something even more: we are no longer a species bound to our planet. We send people into space to live there, to work there. Amazing.

So why didn't I include it on the Top 14 list? Mainly because of the contrast. In the original, you could barely see Dr. Dyson, because she was in shadow and the Earth was so bright. I fiddled with the contrast a lot to get this picture to work at all - you can just barely see her hair floating above her head - but by doing so I made the resulting picture grainy and the colors are a bit off. Because of that, I decided it didn't have the impact of the others I chose for the list.

Perhaps that was a mistake.

[UPDATE Dec. 20, 2010: My brother in law Chris found a much better version of this picture on wikipedia; someone there adjusted it far better than I could have and in fact this is the best version I've seen; had I know of this earlier I would've made it my #2 pick in the main list. I have updated the gallery picture here, and added a link to the big clean version below.]

It truly is an amazing picture. When I first saw it, in fact, I was immediately reminded of this painting, which I wrote about on the blog with the title, "Someday". I had no idea I'd see so similar a tableau in real life just a few months later! We complain that we don't have jetpacks and flying cars, but let me assure you, the future is happening right now.

It's up to us to make sure that the future unfolding before us becomes the reality we want it to be.

Per ardua, ad astra.

Get the hi-res (original) version here, and get a very large version cleaned up here.

Image credit: NASA