Time-Lapse: The ESO Observatories
The northern part of Chile is a forbidding and remote desert. Called the Atacama, it is one of the driest places on Earth, and also reaches high elevations; in some places the desert floor is 4000 meters above sea level… and that’s not counting the numerous mountains and volcanoes that stretch even higher.
All of this is why the Atacama is home to some of the finest astronomical telescopes observatories on the planet. The clear air lets through a lot of light, visible light as well as other flavors invisible to the eye, and the landscape is dotted with bizarrely-shaped observatory buildings and arrays of dishes pointing skyward.
The European Southern Observatory commissioned some of the best astrophotographers in the world to travel to Atacama and capture the ethereal and literally unearthly beauty of the desert… and one of the results is this wonderful time-lapse video called “The ESO Observatories: Atacama Transitions and Landscapes under the Southern Sky” taken by friend-of-the-BA-blog Christoph Malin. Watch.
There’s a lot to see, but I think my favorite is at 6:45, when a bright fireball lights up the sky (that’s the still at the top of this article); you can actually see different colors in the meteor streak, most likely due to different elements burning off it as it plunged into our atmosphere from space.
Right after that, you can watch as the multiple dishes of the ALMA array dance in synchronized perfection, moving in unison to capture faint millimeter waves trickling down from distant cosmic sources.
Also, starting at about 09:50, the buildings housing the magnificent four-part Very Large Telescope come into view; each an 8.2 meter behemoth. At first it’s quite normal appearing, but then the powerful laser erupts from one building, a science-fictional beam that is used to aid the telescope in removing distortion from the ocean of air above our heads. As you can imagine, they have to be careful and coordinate with the local air traffic authorities; such a device wouldn’t be a good mix with an airplane flying into the beam.
Finally, I want to point out a phenomenon that is both subtle and astonishing: At 10:20, with the Milky Way’s companion galaxies the Magellanic Clouds hanging on the left, and a mountaintop silhouetted in the center, you can see faint, colorful bands of light moving in from the right side of the frame. This is almost certainly airglow, caused by atoms and molecules nearly a hundred kilometers above the ground giving up the energy they absorbed from the Sun during the day. This commonly is red and green, as seen in the video.
The ripples in them are amazing. There is wind in the air, even so high off the ground. If it blows steadily across the air below it, ripples can form in the boundary layer (they can also be caused by atmospheric disturbances like thunderstorms, too). These are called gravity waves (the Earth’s gravity fights with buoyancy, and the result is the oscillation of the air, moving it up and down like a cork in water). It’s similar to the phenomenon of ship wave clouds, which happen much closer to the ground.
As usual, there’s far more going on over our heads than we appreciate. Sometimes, it’s when we train our cameras to the sky — and allow them to play with time and space and brightness and color — that we can truly see the exquisite machinery of the heavens.
Two Days Previously
Heh. What was the view like two days before the video I posted this morning?
That's the Orbital Sciences Corporation's Cygnus resupply ship (the Janice Voss) at the end of the space station's Canadarm 2, then leaving in a hurry in this time-lapse video taken on Aug 15, 2014. The resupply ship brought well over a ton of supplies to the astronauts, and had been reloaded with trash. It was unberthed by the remotely-controlled arm (operated by Alex Gerst on the ISS), then commanded to head off. Two days later, it burned up re-entering Earth's atmosphere.
Watching this video I noticed a peculiar thing: It appears to go up, away from the Earth, instead of down toward it. I suspect this is at least partly due to the pictures being taken with a wide-angle lens, which distorts the image; for example, the Earth isn't nearly that curved when seen from ISS. However, the ship didn't burn up until two days later, so it's likely it wasn't sent immediately into a de-orbiting path, so it may have just moved ahead of ISS for a while before dropping down. Things like this can be difficult to track down, so I'll see what I can do to get more info.
In the meantime, the video is mesmerizing, isn't it?
A couple of weeks ago I posted a dramatic picture (above) of the Orbital Sciences Cygnus resupply ship, the Janice Voss, burning up on re-entry after a successful mission to the International Space Station.
Yesterday, astronaut Reid Wiseman posted an incredible Vine video of the event. Watch this!
Wow. I mean seriously, wow. That’s video of a spaceship burning up as seen from above by astronauts on a space station orbiting the Earth.
People keep complaining that we don’t have flying cars. Those people are silly. The future: We are in you.
The Closest Known Exoplanet? Maybe …
In 1992, the first planets outside the solar system were discovered, orbiting the dead cinder of a supernova. Three years later, 51 Peg was found, the first exoplanet orbiting a Sun-like star. Now, after a decade of searching, we have a roster of nearly 2,000 such planets, alien worlds circling alien stars.
They come in many varieties, with some being huge, Jupiter-like behemoths, and others far closer in size to our own hospitable planet. We’ve found them around distant stars hundreds of light years away, and some much closer.
And that brings us to a newly found planet just announced: Gliese 15Ab. It has a mass of about five times Earth’s, which is interesting in and of itself; that makes it a super-Earth, if you will, a planet bigger than us but perhaps not quite massive enough to gravitationally attract a thick atmosphere. We don’t know much about what it’s like, but it’s probably not a gas giant.
But that’s not the interesting bit. The interesting bit is that its host star, Gl 15A, is a mere 11.7 light years from Earth. It’s one of the 20 closest stellar systems known, making GL 15Ab quite possibly the closest known exoplanet!
Gliese 15 is a binary star, two cool, dim red dwarfs orbiting each other. Red dwarfs are the most common type of star in the galaxy, but they’re so intrinsically faint that not a single one is visible to the naked eye; you need a telescope to see them. The closest star to the Sun we know of, Proxima Centauri, is only 4.2 light years away and even then too faint to see without using at least good binoculars.
Gliese 15 A and B (as the two stars are called, or just Gl 15A and B for short) orbit each other at a distance of about 22 billion kilometers, which is five times the distance Neptune orbits the Sun, so they’re pretty far apart. The planet discovered has a very tight orbit around the brighter of the two stars, Gl 15A, circling it a mere 11 million kilometers out. That’s close. Even though the star itself is a dim bulb, the planet is so near to it that it’s heated to at least the boiling point of water, and possibly hotter.
Gl 15Ab was found using what’s called the Doppler shift (or reflex velocity) method. Because the planet has significant mass, as it orbits its parent star in a big circle, the star itself makes a smaller circle every orbit, too. They actually each orbit their mutual center of mass, called the barycenter, like two kids facing each other, holding hands, and swinging each other around. If this sounds familiar, I just wrote about this recently because Pluto and its largest moon, Charon, do the same thing, and this was seen by the approaching New Horizons space probe.
We don’t actually see the star and planet move, but as the star approaches us in its orbit its light gets slightly blue-shifted, and as it moves away the light red shifts. The change is incredibly small, but the team of astronomers used the huge Keck 10-meter telescope with an extremely high-resolution detector. Their observing campaign has gone on for 11 years, enough to detect the planet pretty well. To be clear, they didn’t see the planet directly; they only saw its effect on the star. But this method has proven out many times, and is quite reliable.
The amount the planet can tug on its star depends on its mass, which is how they found the planet to have 5.35 ±0.75 times the mass of Earth, and by measuring the period of the oscillation determined its year to be just 11.44 Earth days long. That’s how they know it orbits the star so closely; that’s a short year!
We’re still new at all this, the finding of alien worlds. But we’re pretty good at it. We know of enough to start looking at them statistically, as a group, able to make some solid extrapolations. Given what we’ve seen so far, we think there are billions of planets in our galaxy alone. Billions! It’s like a Star Trek fever dream come true.
Given those odds, it’s not terribly surprising to find a planet so close to home. I’ll note that this planet isn’t technically confirmed; that is, also found by another team of astronomers or also seen using other methods (like undergoing transits). Still, this observation looks pretty solid, and if so this makes it one of if not the closest known exoplanets. A handful of other planet candidates have been found that are closer, but none is confirmed. There are fewer than 30 known stars and brown dwarfs (substellar objects that are similar to stars but smaller) closer than Gliese 15; many are in multiple systems, binaries or trinaries, so it’s entirely possible we’ll find and confirm a closer planet still.
But even with all that, this goes to show that the sky is likely filled with planets, and many of them are pretty close to us in a cosmic sense. It also shows just how hard it is to find them! Eleven years of searching with one of the largest telescopes on Earth, and it was still a difficult task. But we’re getting better at this. If there are more, closer planets out there, we’ll find ‘em.
Tip o’ the warp nacelle to Dan Vergano.
Double Rainbow ... With Lightning!
One of the things I love about living in Boulder, Colorado, is that in the summer we tend to get afternoon storms. It’s sunny a lot here, which heats the land and evaporates water, forming clouds, and they can get a tremendous amount of energy in them. We get good downpours, and then when the storm is done, it’s done.
Because the wind blows predominantly west to east, and the storms are in the afternoon when the Sun is setting, when the clouds clear from the west the Sun shines through. If it’s still raining here, we can get extremely bright rainbows.
That weather pattern was common for the first couple of years I lived here, but in recent years it’s slacked off. But it’s coming back: Yesterday was a textbook case of this, and the rainbow was amazing.
Yeah, double rainbow all the way. The glow around my head’s shadow I was describing is called heiligenschein. The other optical effects—the secondary arc, the supernumerary arcs, the bright region in the center and the dark band—I’ve described recently in a post about red rainbows.
The lightning was amazing. It was so fast I didn't get a good look at it—I was paying attention to the phone screen to make sure the rainbow was visible in it—and for a moment I thought it might have been sunlight reflecting off raindrops. Then a few seconds later the thunder slammed down. It was far louder than it sounds on the video. It took about eight seconds to reach me, so the lightning was less than three kilometers away. Quite the show.
I will never get tired of seeing things like this. Rainbows are almost cliché, but they’re one of the most magnificent optical displays nature can provide. The science behind them is really intriguing, and to me, it amplifies their beauty manyfold.
The Slate Plus Doctor Who Inaugural Podcast
Note: Extremely mild spoilers below. I figure I might as well warn you.
As an unapologetic and enthusiastic Doctor Who fanboy, I’m really happy that the new series has started up. We’re in Season 8 now, with Peter Capaldi now (metaphorically) filling the Doctor’s fez. The first episode just aired, and I thought it was pretty good. I even tweeted it:
I am going to go out on a limb here and say I really liked the new Doctor Who episode.— Phil Plait (@BadAstronomer) August 25, 2014
So it’s official.
The Hive Overmind at Slate asked if I’d like to do a podcast with various Slate-sters discussing the new episodes of Doctor Who as they air. I said yes—duh—and the first one is now online. I spent about an hour talking Whovianicity with Slate’s Outward editor and culture critic June Thomas. We talk Clara, Capaldi, robots, Silurians, and why I thought the regeneration was handled pretty well. We also had some fun with a certain locking of lips shown in the episode as well.
Fair warning: The podcast is part of Slate Plus, which is a premium subscription service. It’s five bucks a month, and provides all kinds of fun added content; I’ve written about it before. There’s a lot of great stuff there on top of the usual great stuff at Slate, so I heartily recommend signing up.
If you need another reason, we’ll have a new Doctor Who podcast every week during the season. So join in and be a part of the fun!
An Island Grows in the Ocean
Back in March I posted a Landsat 8 image of a volcano called Nishinoshima, located in the Pacific Ocean about 1,000 kilometers south of Tokyo. Up until late 2013 it was just a dinky island barely poking above the water’s surface. But then a second vent started erupting nearby, rapidly grew in size, and actually engulfed the original volcano.
It’s still growing. This new view from Landsat on Aug. 21, 2014, shows it puffing away:
It’s interesting comparing it to how it looked a few months ago; it’s clearly changed its shape. It’s not growing as rapidly as it once was, apparently, but it’s still getting bigger.
That whole area is loaded with volcanic islands forming seriously long chains across the ocean:
The pin marks the location of Nishinoshima. Of course, that map is scaled way out, covering thousands of kilometers. The original Landsat image gives you a better sense of how lonely the island is out there:
Pretty. And fascinating. It shows that our planet is active, constantly changing, constantly renewing itself. If it didn’t, we’d probably look a lot more like Mars. That’s a pretty amazing planet too, but given its lack of a thick atmosphere, no water, and chilly room temperature, I’ll take Earth every time. I like my environment habitable, even if it means some locally isolated places really aren’t.
No, There Still Is No Connection Between Vaccines and Autism
There's a conspiracy theory going around that the CDC covered up a link between autism and vaccines. From what I can tell, this conspiracy theory is on the same level as the one that NASA faked the Moon landings. And you know how I feel about that.
Perhaps you’ve heard about this CDC theory; it’s burning up on Facebook, Twitter, and other social media. The gist of it is that a “whistleblower” at the Centers for Disease Control and Prevention has revealed some hanky-panky done by researchers there to cover up a link between vaccines and autism found in a certain group of babies, and a new analysis supposedly shows this connection.
It’d be a compelling story, if it were true. However, it appears very strongly to be false. Since I am not an expert in the specifics, I direct you to two posts: "Did a high ranking whistleblower really reveal that the CDC covered up proof that vaccines cause autism in African-American boys?" by Dr. David Gorski at Science Based Medicine, and “Andrew Wakefield Tortures History” at Harpocrates Speaks. These, together with links therein, show to my satisfaction why this conspiracy claim is more heat than light. As the first post by Gorski shows, the "new analysis" fails for multiple reasons, including using small numbers for statistics (a big no-no), applying statistics incorrectly, and not even employing an actual statistician for the analysis. There are other very serious problems as well, all of which are laid bare in those posts.
I'll note that the conspiracy theory is endorsed by Andrew Wakefield—called a fraud by the BMJ, guilty of scientific misconduct, and father of the modern anti-vaccine movement. That right there is enough for me to be extremely suspicious of it. Coupled with the evidence outlined above? Done.
To be clear: Although it’s been tested over and again, no causal connection has ever been found between vaccines and autism … and it’s not just the CDC and other U.S. facilities that have worked on this; it's been an international effort.
Stuff like this used to make me really angry, but now it makes me sad. Diseases like measles, pertussis, chicken pox, and polio are dangerous, and they’re making a comeback, in no small part due to misinformation spread by anti-vaxxers.
I know that many of the people making these claims are honest; they're speaking from their heart out of concern for their children. As a parent and a human being, I’m concerned about this as well. And that’s precisely why I write about the realities of vaccines: They are extremely effective, and their risk is incredibly small compared with their benefits. Conspiracy theories like this new one have the potential to do a lot of damage. Ironically, by avoiding vaccinations, the people it’s likely to hurt are the very ones their parents are trying to protect.
Man, that’s a weird title.
But it’s accurate enough. I’ve written about noctilucent (literally, “night shining”) clouds a few times recently. These weird, high-altitude clouds appear to be more common in recent days, and it’s not clear why (global warming is one culprit). But they are visible just after sunset and before sunrise, lit by the Sun that to us on the ground is below the horizon. They take on a shimmering, silvery cast, and are quite stunning.
Neat! You can see lower-altitude (aka “normal”) clouds moving in from the east, contrasting with the much higher noctilucent ones.
These are still on my to-do list of must-see clouds, together with roll clouds and a big scary mesocyclone forming over the Midwestern plains. And an aurora, come to think of it. And a total solar eclipse, sure. And finding my own meteorite.
I’m not picky; any order of these will do. As bucket lists go, this seems doable. I have my feet on the ground ... but my head in the clouds.
“Everybody, Remember Where We Parked”: Choosing a Landing Site on a Comet
The Rosetta spacecraft successfully rendezvoused with the comet 67/P Churyumov-Gerasimenko in early August, and has been tagging along with the weirdly-shaped double-lobed dirty iceball ever since. It’s been taking extraordinary pictures and making lots of other measurements, sending them back to the Earth over 400 million kilometers away.
Scientists are poring over the data; not just to study the comet for science, but also to prepare for the next big step in the mission: Setting the lander Philae down on the surface.
Choosing a landing spot is difficult. There needs to be something interesting going on there, since the lander is loaded with scientific instruments that will poke and probe its immediate environment (including drilling down into the surface and analyzing what it finds). But the lander needs to be kept safe, too. That means the terrain (cometain?) needs to be relatively smooth; boulder fields may prove to be somewhat hazardous. But the comet spins once every 12 hours, and lighting conditions can change radically also, affecting the long-term science planning. I expect the surface itself will need to be thought through carefully; the lander will anchor itself using harpoons shot into the ground, so a light fluffy material may not provide the traction needed.
After looking over the images sent back, an initial ten landing potential landing sites have been narrowed down to five. The regions are indicated in the picture at the top of this post (note that the letters are not a ranking; the original ten were just lettered A – J). The OSIRIS camera was used to get better close-ups of the regions for examination. Here’s spot A:
This one is on the bigger of the two lobes, and has the advantage of being a good place to observe the smaller lobe, too. This looks like a place where loose material has flowed down, given how smooth it appears. However, there could still be small depressions of other hazards here, so the examination continues.
Here’s landing spot B:
I’m guessing they won’t go with this one; the presence of so many large boulders means landing could be difficult. But the area above the boulder field does look pretty smooth.
These are images taken at one given time, and more are being taken to investigate the areas under different lighting conditions as the comet rotates. That will highlight things like bumps, pits, and so on, as the shadows change.
The decision will have to be made soon; Philae is scheduled to deploy in November. Rosetta is already dropping down toward the comet; the initial 100-km standoff distance has been lowered to 60 km, and it’ll get closer yet before sending Philae on its way. I’m getting pretty excited by all this! The images and data we’re getting now are already quite amazing, but they’ll get far better as the probe nears the surface.
And then, finally, as Philae heads for the comet, we’ll see what one of these things looks like up close and very personal.