Top Ten Astronomy Pictures of 2010 – Runners Up | Bad Astronomy

 
 

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via Discover Master Feed on 12/20/10

When I made my Top 14 Astronomy Pictures of 2010, it was really tough cutting some out. This is a gallery of the images that, for whatever reasons, I decided to leave off. They're still spectacular and gorgeous, though! Click on the thumbnail in the slider to go to an image, use the arrows to navigate back and forth, and click on the big image displayed below to get more info and a bigger version if available.

Is there anything more magnificent than a 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. <br /><br />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 then 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. <br /><br />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.<br /><br /><strong>Get the hi-res version <a href=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 <strong>we</strong> were the ones who made it: it was formed when the upper-stage Saturn V booster from Apollo 13 slammed into the Moon!<br /><br />This Lunar Reconnaisance 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.<br /><br />I almost put this in the Top 14 list, but the LRO shot of the boulder that rolled into the crater tickled me more. <br /><br /><strong>Get the hi-res version <a href=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. <br /><br />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!<br /><br /><strong>Get the hi-res version <a href=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.<br /><br />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. <br /><br /><strong>Get the hi-res version <a href=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! <br /><br />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.<br /><br /><strong>Get the hi-res version <a href=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!<br /><br />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 <a href=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 Why is there a giant dart board on Mars?<br /><br />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 <a href=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 <em>a million one-megaton bombs!</em><br /><br />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!<br /><br /><strong>Get the hi-res version <a href=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.<br /><br />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.<br /><br /><strong>Get the hi-res version <a href=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.<br /><br />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 <em>previously</em> blown off! <br /><br />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.<br /><br /><strong>Get the hi-res version <a href=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.<br /><br />But it's a coincidence: the star is 650 light years away, the galaxy 14 <em>million</em>. 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!<br /><br /><strong>Get the hi-res version <a href=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 <a href=



 
 

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