Bad Astronomy Gallery
(click any image to see it full size)
My picture choices may surprise you. I didn't just pick them for their beauty, but also for the story they tell, what happened behind the scenes, and simply because they're cool. I hope you agree. Whether you do or don't, leave a comment and link to your faves!
Solar system picture credit: Wikipedia/NASA
Look to the upper right: see those shadows? Those aren't sunspots: they're the International Space Station and Space Shuttle Atlantis silhouetted in front of the Sun! This image was taken by the incredible "amateur" astronomer Thierry Legault in May 2010. Because the Sun is so bright, the exposure time is very short, freezing out the usual atmospheric blurring. That makes the picture extremely crisp and details easy to spot -- see for yourself in the super-high-res version. And don't be fooled by the apparent motionlesness of the duo: screaming above the surface of the Earth at 8 km/sec (5 miles/sec), they transit the Sun's face in less than a second! It took a lot of planning and good timing to pull off this amazing picture.
Related post: ISS Shuttle transit the Sun
Credit: Thierry Legault
MESSENGER is doing a series of gravitational loop-de-loops to get to Mercury, and has passed the planet three times already. In October 2008, during its second flyby, it took this astonishing picture. It shows two prominent fresh craters on the airless planet, but also a series of vast, world-spanning rays: plumes of material ejected from an impact. Their existence had been inferred from earlier observations, but this was the first time they had been directly seen. We'll learn a whole lot more about Mercury when MESSENGER finally settles into orbit in March 2011.
Related post: Watermelon Planet
Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington
While I watched the 2004 transit myself with my own eyes, NASA's solar-observing TRACE satellite saw it as well. Pictured above, you can see the transit in visible light (top) -- scattering of sunlight by the thick atmosphere of Venus makes it look like a complete ring -- ultraviolet (bottom left) and the far UV (bottom right). Astronomers were able to learn about Venus's air during this event. Also, planets around other stars have been detected when they transit their stars, so observations like this in our own solar system give us insight into the physics of these events.
At closest approach, Rosetta skimmed the Earth at a distance of just 6000 km (3600 miles) above the surface! Close enough to feel the breeze from it... if it weren't for that whole "vacuum of space" stuff. As it was, the spacecraft accelerated by about 13 km/sec (8 miles/sec), enough to boost it on its way to meet up with a comet. When it arrives, it will deploy a lander that will touch down on the surface of the comet and study it up close and personal, giving us our best view yet of these objects.
Related post: Rosetta Takes some home pictures
Credit: ESA © 2005 MPS for OSIRIS Team MPS / UPD / LAM / IAA / RSSD / INTA / UPM / DASP / IDA
The crater is about 10 km (6 miles) across, and is a candidate location for ice frozen under the surface. Scientists have recently discovered that the Moon has quite a bit of water ice trapped under the surface dust, and places like Erlanger -- which never see the warming rays of the Sun, even after billions of years -- may have huge reservoirs of water eternally frozen at their bottoms. This would make Erlanger a good place to have a lunar base: water is abundant, and solar cells along the rim would deliver power 24 hours a day -- sorry, I mean 655 hours a lunar day.
Related post: Lunar Boreal Halo
Credit: NASA/GSFC/Arizona State University
Unlike Earth, Mars is covered in sand and dust. The sand is made up of dark gray basalt, and is heavier than the much finer-grained red dust which covers it. So when a dust devil sweeps over the ground on Mars, it lifts up the red dust and blows it away, revealing the gray sand underneath. And when dozens of them do it in one region, you get this incredibly beautiful Martian calligraphy.
Related post: Martian Swirly
Credit: NASA/JPL/University of Arizona
This is actually a mosaic of 27 images! It took a 3x3 picture grid of the planet, then repeated it twice to get it through red, green, and blue filters. That way, astronomers back home could stitch them together to make this beautiful and moody true-color picture of the solar system's biggest planet. The detail on the original are incredible; you can see hundreds of small storms raging across the planet, as well as subtle colors and other features. Remember: Jupiter is 86,000 miles across, 11 times the diameter of Earth! Keep that in mind when you see something in this picture that looks "small".
Related post: Cassini: ten years since Jupiter
And that's why I love this Saturn shot from Cassini. Taken from high above the plane of the rings, Saturn is a little more than half full. The rings appear darker than usual, and that's because on the day before this picture was taken, Saturn experienced its spring equinox. That means the rings were pointed edge-onto the Sun. Instead of the sunlight falling on the rings, illuminating them, it was hitting the edge. So the rings appear dark, and with Saturn half-lit the way it is, this picture is more brooding than most cheery, well-lit pictures of the ringed planet. Sure, the famous shot of the back-lit planet with the Earth peeking between the rings is more famous, but this one has a depth and a color to it that really appeals to me.
Credit: NASA/JPL/Space Science Institute
The image above is from Hubble Space Telescope's NICMOS camera, which can see infrared light. It shows the planet, of course, and its rings, but also 10 of the giant planet's moons, as well as an incredible band of storms raging across the cloud tops. The colors of the clouds indicate depth: blue comes from deeper clouds (methane in the atmosphere absorbs red light-- the same reason deep water looks blue), yellow and gray from high clouds and haze, and the orange and reds from extremely high clouds. Also note the angle of the planet: it orbits the Sun tilted over "on its side", so even from Earth we can trace the rings circling all the way around the planet.
Related post: Yes, yes: rings around Uranus, haha
Credit: Erich Karkoschka (University of Arizona) and NASA
Pluto crosses Neptune's orbit, but due to the timings of their motion they never get very close; Pluto is in no danger of crashing into Neptune. So this picture taken by New Horizons is from a long way off: 4 billion kilometers, in fact! Neptune actually gets closer than this to Earth sometimes... which may give you an idea of just how far away this spacecraft is. The shot shows Neptune (overexposed in the middle) as well as its frozen moon Triton. Pluto and Triton have quite a bit in common -- they're about the same size, temperature, and have the same atmospheric composition -- so this was a good practice shot for the mission. It also gives me a lot of confidence that when it does pass by Pluto, we'll get some amazing pictures.
Related post: Why King Triton, how nice to see you
Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute
Either way, the image here was an awesome achievement: amateur astronomers on Earth were able to take pictures of Pluto that actually show its moon Charon! Given that the moon wasn't discovered until 1978, by a professional astronomer using a big telescope, getting this shot really was an incredible accomplishment. Amazingly, the telescope used for this image was a 35 cm (14"), far smaller than the one used to discover Charon, and in fact this image is far superior! We've come a long, long way in the past 30 years.Coelum Astronomia, Daniele Gasparri, and Antonello Medugno
When I was a kid, there were 9 planets. We really didn't know if other stars had planets circling them or not. Today, we now know of hundreds of these exoplanets, detected using various means. But it wasn't until 2008 that we finally clutched the Holy Grail: a bona fide, 100% confirmed direct image of one of these planets.
The image above is from the Hubble Space Telescope. It was observing the bright star Fomalhaut, which you actually can't see in the image because its light was blocked purposely so that fainter material around it could be seen (just like when you look for an airplane near the Sun and block the sunlight with your hand). The ring is a vast torus of dust leftover from the formation of the system, and we knew from its shape there might be a planet near it. And sure enough, an image from 2006 was compared to one taken in 2004, and a moving dot was found: the planet Fomalhaut b. It orbits the star at a distance of 16 billion km (10 billion miles), much farther out than Neptune is from the Sun. That's why we could see it at all; had it been much closer it would be lost in the glare of the star, a billion times brighter.
I love this picture (as well as another released at the same time of more planets orbiting a different star): it is solid evidence that we are learning more about our Universe everyday, and that questions we have had for centuries, for millennia, are answerable if we put our considerably clever minds to them.
Related posts: Huge exoplanet new items: pictures!
Credit: NASA, ESA, P. Kalas, J. Graham, E. Chiang, E. Kite (University of California, Berkeley), M. Clampin (NASA Goddard Space Flight Center), M. Fitzgerald (Lawrence Livermore National Laboratory), and K. Stapelfeldt and J. Krist (NASA Jet Propulsion Laboratory)