The entire universe in blog form

April 24 2014 11:30 AM

Global Vaccination Week: Are You Up to Date?

Are you up to date with your vaccinations?

That’s the theme of this year’s Global Vaccination Week (Apr. 24–30, 2014), a big health effort by the World Health Organization. The goal: Save millions of lives, many if not most being children’s.


Yes, you read that right. Estimates are that vaccines save about 8 million lives every year. Measles alone kills more than 100,000 people every year worldwide … and that number was a terrifying 2.6 million deaths before 1980, when the vaccine was introduced. Just from measles. Measles, a disease that is so rare nowadays that in the United States fatalities are almost unheard of.

That’s because of vaccinations. More than a billion children have been vaccinated against measles since the year 2000, and deaths have dropped by nearly 80 percent.

Vaccines work. Smallpox killed hundreds of millions of people in the 20th century. By 1978 it was gone. Why? An intensive global vaccination effort wiped that scourge off the planet. There hasn’t been a case in the wild since 1977.

The list goes on. Polio, diphtheria, pertussis, and more—terrifying diseases, and in general ones that attack children more than adults—are all on the decline globally due to vaccinations. But we can do better.

Unicef infographoic
This is one part of a great infographic put together by UNICEF USA. Click to see the whole thing.


Vaccines of course help prevent you from getting infected, but they also help lessen the severity of an infection if you do wind up getting sick anyway. And through herd immunity they also help prevent infections of people who cannot get vaccinated (very young infants and immunosuppressed folks, mostly). I’m all for saving the lives of babies.

And yet, despite this mountain of evidence and long history of success, anti-vaccination efforts continue apace. Jenny McCarthy, perhaps the best known mouthpiece of vaccine misinformation, claims she’s not anti-vax in a shameless op-ed (and has her head handed to her for it). Actress Alicia Silverstone has jumped on that bandwagon in a recent book on parenting. In Denver, a bill making it harder for parents to opt out of vaccinations for their children was shot down.

I hate that this has happened the way it did, but some moms are speaking out due to losing a child, like Shannon Duffy Peterson, whose daughter Abby died at the age of 6 from complications due to chicken pox. My friends Toni and David McCaffery lost their daughter Dana at the age of four weeks to pertussis and are now vocal public advocates for vaccination. Deb Proctor had one child suffer a brief reaction to a rotovirus vaccine, but her two other children (as well as she herself) contracted pertussis, whooping cough. She’s lived through both sides of this, and now strongly supports vaccinations.

We need to make sure people are aware of the facts of vaccinations, both for adults and children.

And that leads us back to the Global Vaccination Awareness week. Are you up to date on your vaccines? I am. My wife is as well, and so is our daughter (who is attending college next year, and has to prove she’s vaccinated to enroll). This is as good a time as any: Go see your board-certified health practitioner, and find out if you need boosters.

The life you save may be your own. Or it may be an infant up the street, or a cancer surviving co-worker with a low white blood cell count, or just some innocent kid whose parents decided to opt out based on bad information. It’s up to all of us to do what we can to protect the health of all of us on this planet.

Do what you can.

Video Advertisement

April 24 2014 7:30 AM

For Hubble’s 24th Birthday: A Stellar Nursery Being Destroyed by the Stars It Created

Today marks the Hubble Space Telescope’s 24th birthday; on this day in 1990 the Space Shuttle Discovery roared into space with Hubble in the payload bay, and the next day astronaut Steve Hawley deployed the telescope into orbit. For years a flaw in the mirror degraded the resulting observation but upgrades to the cameras onboard the observatory compensated, and ever since Hubble has been wowing astronomers and the public alike with its grand view of the Universe.

Every year on or about this date, the folks at the Space Telescope Science Institute release a gorgeous image to celebrate (see Related Posts below). This year is no exception; in fact, this year’s is one of the best: NGC 2174, a vast stellar nursery being blasted away by the ferocious light and heat of nearby stars.

New Hubble image of NGC 2174
NGC 2174, in the process of destroying itself. Click to ennebulenate.

Photo by NASA,ESA, and the Hubble Heritage Team (STScI/AURA)


Holy wow! NGC 2174 is about 6,000 or so light years away toward the constellation of Orion, and is a huge cloud of gas and dust enthusiastically forming stars at a brisk clip. And I do mean huge: Even at that terrifying distance, the entire cloud is as big in the sky as the full Moon. This small section of it seen by Hubble is a half-dozen light years across all by itself, and the whole cloud is more than 10 times larger.

The gas and dust in NGC 2174 have been forming stars for millions of years, and it is populated with quite a few young, massive, hot, and very luminous ones. Just off to the right in the picture, outside the field of view, is a whole cluster of them. These stars are so bright that their light and winds of subatomic particles are eating away at the cloud, dissolving it. What you’re seeing here is the edge of that erosion front, the border between material already blown away and material that is soon to be destroyed by it.

Detail of NGC 2714, showing knots of material eroding away.

Photo by NASA,ESA, and the Hubble Heritage Team (STScI/AURA)

This region is studded with bumps and long fingers of material; these are denser knots where stars are forming deep within. The gas and dust are thicker here and resist erosion. The knots act like sandbars in a stream, forming graceful arcing heads upstream and long tails pointing away from the hot stars. The very edges of the heads are glowing as they undergo the onslaught from the nearby superstars, creating a bright limb around them.

I can’t help but think they look like sperm (though we’re talking gametes a trillion kilometers long …). The metaphor isn’t a bad one, since these are the sites where stars are being born. And it’s a race to see which knots can actually birth their stars before being blown away by the winds. The similarity in shape is due to similarity of forces; both are sculpted by hydrodynamics, the motions of fluids. On the microscopic side sperm get an advantage by being sleek and streamlined so they move more efficiently through a fluid; on the cosmic side the knots get sculpted as the fluid flows past them. Animal birth, star birth: The motion of the medium is relative.

One last thing I want to point out, too. In the detail shot above you can actually see a few background galaxies. That’s amazing! The dust littering NGC 2174 is very efficient at absorbing light, and it’s rare to see more distant objects in pictures of star-forming regions. In this case though we have an ace in the hole: This image was made using infrared filters!

Infrared light is better at getting through the dust, so some galaxies are able to pierce the muck. Note that as you look more to the left in the big Hubble image you see fewer stars and galaxies, and things get redder. The really thick dust is on the left, and it blocks almost everything behind it. But some of the stars embedded in the dust manage to get their reddest light through. I can still spot a handful of galaxies there; I imagine these are very luminous beasts indeed to be able to shine through, pouring out infrared light. Perhaps they themselves have huge clouds like NGC 2174, vigorously forming stars and blasting infrared light out into the Universe, and it’s that glow we see here.

The Universe is very meta sometimes.

Anyway, happy birthday, Hubble! It was a pleasure to work on you for all those years, and even more of a pleasure to continue writing about your exploits now, nearly two and a half decades after you got your start.

Related Posts

April 23 2014 12:00 PM

Hubble Drills Deep Into the Universe

What happens when you take a 2.4-meter telescope, launch it into space, and command it to stare at one spot in the sky for a solid 14 hours, taking data both in visible light (like our eyes see) and infrared?

This. This.

Hubble’s cross-section of the cosmos
Give me a moment to tell you why this image will destroy your brain. Click to nicely galactinate, or click here to hugely do so.

All photos by NASA/ ESA


Can I get a “Yowza!” from the congregation? No? Maybe that’s because when I shrink this Hubble Space Telescope picture down to fit the blog you can’t really get a sense of what you’re seeing here. So click the picture to get the 1280 x 1280 image, or better yet, do yourself and your eyeballs a favor and take a poke at the huge 3900 x 3900 pixel version, because holy wow.

What you’re seeing here is a view of thousands of galaxies. Thousands. Sure, there are some stars in our own Milky Way punctuating this picture here and there but they are few, and just stomped flat by the number of whole galaxies you’re seeing. The stars can be distinguished from galaxies because they’re point sources; small dots. They also might have those lines going through them called diffraction spikes. Galaxies don’t usually get those because they’re fuzzier, spread out over many pixels. That suppresses the diffraction spikes.

So for example that bright point with pretty spikes you see toward the upper right is a star, probably a few thousand light years from Earth. That’s a long way to be sure, but even the nearest galaxies you can see in this image are hundreds of millions of light years away! Some are billions; the most distant object in this shot are at least 9 billion light years distant. That’s a million times farther away than any star in the picture.

When the light we see here left those galaxies, the Sun hadn’t yet formed. When the Earth itself was coalescing from countless specks of dust, that light still had half its journey here ahead of it.

So yeah. This stuff is far.

Hubble’s cross-section of the cosmos
CLASS B1608+656, a cluster of galaxies far, far away.

In fact you’re seeing galaxies at all different distances from Earth in this image, but the observation itself was taken to look at the cluster of galaxies in the center. Called CLASS B1608+656, it’s a clump of galaxies about five billion light years away. The mass of that cluster acts like a lens, bending space, magnifying objects behind it. This gravitational lens has distorted and amped up the brightness of a luminous galaxy located an additional several billion light years behind it, creating the weirdly shaped mess you see in the close-up above. Rings and arcs are common in such events.

But there’s so much more to this image; just scanning across it reveals an incredible variety and diversity of galaxies. Remember, too, you’re looking at objects as they existed eons ago; many are still growing, suffering collisions with other galaxies, giving them fantastic shapes. As an example, I’m fond of this little group near the top of the main image:

Hubble’s cross-section of the cosmos
A cosmic train wreck a million light years long.

I’m not precisely sure what to make of this. The bigger galaxies look to all be about the same distance from us, but that could be a coincidental alignment. Some of the galaxies are blue and clumpy looking, indicating they’re aggressively forming stars (hot, young, massive stars are preferentially blue), while some are quite red. The red ones may be very dusty, which reddens the light from stars, or they may be farther away, their light redshifted as it fights against the expansion of the Universe itself, losing energy along the way. It may be a mix of both. Unfortunately, this image was made using only two filters, so colors can be difficult to interpret, and don’t yield a lot of subtle information. The only way to know more about the galaxies would be to measure their distance, and I didn’t find anything in the literature about them.

That’s worth taking a moment to ponder, actually. These are entire galaxies, collections of tens of billions of stars, planets, dust, and gas clouds, each and every one a monstrous object on scales that dwarf our everyday experience … yet there are so many of each of them in this image alone we can’t possibly know their details. We can determine their coordinates on the sky, get a rough estimate of their distance, but there is simply no way to get a measure of them as individuals. They are too many. It’s like trying to get the life history of everyone who passes you on a busy New York City street corner. The task is too overwhelming.

And just in case I have not yet crushed your puny human mind, this image represents a tiny fraction of the entire sky; perhaps only one ten-millionth of it. That means there are hundreds of billions of galaxies like these scattered throughout the Universe.

So gaze again at that image, one that drills a narrow but incredibly deep view through our cosmos, one that shows us both the awe-inducing grandeur and soul-squeezing immensity of it, and remember: The Universe is far, far larger than this still.

And yet here we are, pondering it. To those galaxies, we are the ones who are lost in the anonymous throng. Yet I would argue we are as important and interesting a piece of the Universe as any other we can imagine. We are part of it at the same time as we study it, and to me, that is part of what makes us great.

April 23 2014 7:30 AM

Black Skies, Smiling at Me

This week, April 20–26, 2014, is International Dark Sky Week, a global effort to get people to appreciate the skies above them. Light pollution—excess light thrown into the sky by street lights, houses, buildings, and pretty much everything that makes light—reduces our ability to see the stars, sometimes dramatically. I lived in Chicago for a year, and on the clearest nights I could only see the very few brightest stars, struggling against the mighty orange glow of the city projected upward.

This light is wasted; it’s money thrown away, it’s low-efficiency, and in many cases the lights being used at night aren’t really doing a good job of illuminating the ground and making it safer.


Astrophotographer Mark Gee (who has been featured on my blog before; see Related Posts below) made a short and lovely video to highlight the issue. His work is stunning and well worth your time.

Years ago, my wife and I took a weekend vacation to a campground in rural Virginia; it was a camp I attended a couple of times as a kid. The owners were family friends, and one weekend every year they had old friends over to spend time together and enjoy the gorgeous scenery.

We parked near the main house, and as we fussed inside the car getting our belongings together, another weekend-goer walked by us while he talked on his phone. We overhead one snippet of his conversation, where he said “… and you should see the sky at night here. It’s so dark, and there are thousands of stars!”

I turned to my wife and we smiled at each other. He had no idea an astronomer was sitting there and could hear him; that was a spontaneous exclamation from someone who simply had never seen a dark sky before, and was properly overwhelmed by it.

That night we all sat in a field and watched the brilliant stars sparkling in a field of velvety black. It truly was amazing, mesmerizing, surpassingly beautiful. The artwork of nature, displayed for all to see …

… who have the skies to see it. This experience is what light pollution is stealing from us, and this is why I support what the International Dark Sky Association is doing to raise awareness of it. They have a different theme every day this week talking about our brightening skies, and I encourage you to take a look to see what they’re doing about it. The sky belongs to all of us, and we all deserve a chance to see it.

Related Posts

April 22 2014 7:30 AM

10 Planetary Facts for Earth Day 2014

Today is Earth Day, a worldwide celebration of our home planet. I know you’ll be hearing a lot of talk about the environment today, humanity’s global impact, and more … which is great, and I wholly support that conversation (obviously).

But as an astronomer and science dork, I do love me some fun factoids. So I gathered together/calculated a few to give you a better appreciation of our planet’s place in the Universe. You might want to check out the ones I posted last year, too. You can’t know too much about Earth.


1) Earth Day is April 22 every year. On average (jumping over leap years and such), between subsequent Earth Days our planet moves about 940 million kilometers (580 million miles), the circumference of its orbit around the Sun. That means it’s faster—way faster—than a speeding bullet: about 30 km/sec (18 miles/sec)! Typical rifle bullets travel 1-2 km/sec, so the Earth outpaces them handily.

[UPDATE (Apr. 22 at 18:00 UTC): I'm getting some comments about this, mostly referring to how I measure that speed. Implicit in my words is that I meant relative to the Sun, so that's how quickly the Earth would move around the Sun. In general, the speed of the Earth (or anything) depends on what you're measuring its speed against. Since I'm on Earth, it's not moving at all relative to me, and if you're in a distant galaxy we're moving away at a large fraction (or even faster than) the speed of light. All motion is relative... you can quote me on that!]

2) It’s not a small world after all. The surface area of the Earth is about 510 million square kilometers, or 197 million square miles. It’s not a perfect sphere (see listing No. 4 here), but if it were, using the surface area to find the Earth’s diameter would give you a ball 12,742 km (7,900 miles) across.

Venus with goatee
In hindsight this should've been obvious.

Photo by NASA & Tatiana Yurchenko/Shutterstock & Phil Plait

3) The Earth is the biggest of the terrestrial (rocky, as opposed to Jupiter-like gas giant) planets in our solar system.

4) Venus, the closest planet in the solar system to Earth’s size, has a diameter of 12,104 km (7,504 miles), 95 percent the width of Earth. It has about 82 percent the mass of Earth, too, making it our twin. However, its thick atmosphere is mostly carbon dioxide, it rains sulfuric acid, the air pressure on its surface is 90 times Earth’s, and the average temperature is a lead-melting 460 C (860 F). So it’s more like our evil twin.

5) Nearly 2,000 confirmed exoplanets (worlds orbiting other stars) have been found so far. The smallest, Kepler-37b, is barely bigger than our own Moon! Another, KOI-314c, has the same mass as Earth but is so hot it’s puffy, with a huge atmosphere. The planet that has the best chance of being most like Earth is Kepler-186f, which has 1.1 times the Earth’s diameter and is the right distance from its star to have liquid water. We really don’t know what it’s like beyond that, though. It might be more like Venus, or Mars.

6) We’ve only just started looking for other planets, though. There may be billions of Earth-size planets in our galaxy alone.

south of Earth
The vast majority of the Southern Hemisphere is water. This is more obvious when you look down from over the South Pole.

Photo by Google Earth

7) Coming back home again, Earth has something no other planet we know of has: a lot of water on the surface. It’s about 71 percent water by area, dominated by the Pacific Ocean, which covers a staggering 155.6 million square km (60 million square miles) of the surface. That’s nearly a third of the planet.

8) Most of the Southern Hemisphere (by a long shot) is covered in water: About 80 percent of the planet’s area south of the equator is water. North of the equator it’s about 60 percent.

9) Water exists naturally in all three physical states on Earth’s surface: solid (ice), liquid, and gas (water vapor). Due to a peculiar property of water—called its triple point—it can even exist in all three states at the same location and time. So now when things go wrong, you can say, “Well it could be worse: It could be raining and snowing and steaming!”

10) The more we look, both in our neighborhood and in deep space, the more we find that our Earth is one-of-a-kind. Even if we do eventually spot those billions of other planets similar in size to Earth, it’s unlikely they will be just like ours, with our exact balance of chemistry, temperature, and life. Heck, in the distant past the Earth didn’t look like it does now, and it’s the same planet.

What this tells us is that what we have now is precious, unique, and vital to us and ours. We don’t have an emergency backup, a summer home, a spot we can retreat to. The Earth is all we’ve got. We need to treat it that way.

April 21 2014 11:06 AM

Slate Plus You

I’ve been writing for Slate for about a year and a half now, and one thing I like about the magazine is that it’s all online; there’s no print version. That means there’s not a lot of baggage leftover from print media (which a lot of bloggers—including me sometimes—call “old media”). The folks behind the scenes have been working the ‘Net a long time and know their way around.

That means they’re also willing to try new things, and we’re rolling one out now that I think looks pretty interesting: Slate Plus. This is premium content, added material, including podcast extras, interviews, early access to Slate events, behind-the-scenes stuff, and more.


Our fearless leader, David Plotz, explains what this is all about, but in a nutshell Slate Plus is a membership program; monthly access is $5, and yearly is $50. Mind you, this is not a paywall; Slate will still be free, and you need pay nothing for the usual yammering from me and all the other writers here you’ve been seeing all along. But Slate Plus has more stuff and more access. There’s a free trial for two weeks you can try if you take a look now.

If you do want to sign up, I ask you use this link to become a member of Slate Plus. Why? Well, for one thing, if you do you'll get a $5 credit, essentially a month for free. So yay!

Also, we’re running a contest among Slate staff and contributors to see who can gather the most sign-ups, with a tidy (if modest) monetary award going to the top hunter/gatherers. I have no clue if I will place in the top tier or not, but if I do, I will donate that money to, which is like a KickStarter for school science funding. Teachers in undersupported schools put together projects for their kids and ask for donations from the public. This is a great organization doing a lot of good for students all over the U.S., so I’ll be happy to send some filthy lucre their way if enough of my droogs here sign up for Slate Plus.

So give it a shot! I’ll note that we’re still trying to figure out what I can do to contribute to Slate Plus as well. Maybe you should tell me what you’d like to see! An interview every now and again, a light-hearted debate with another Slatester, a video tour of my ridiculously entropic home office? Leave a comment and let us know!

And, as always, thanks for reading my blog. With or without Slate Plus, it’ll be right here where you left it, don’t worry.

April 21 2014 7:30 AM

A Dragon Chases the Space Station

Dragon and ISS
A Dragon chases down a huge denizen of space. Click to embiggen.

Photo by Bill Longo, used by permission

I post a lot of images taken with some pretty nice astronomical gear, from “amateur” telescopes up to multibillion dollar space observatories.

But it doesn’t always take a lot of fancy equipment to get great shots. Sometimes it just takes a camera, a tripod, and a little foreknowledge.


Armed with just this, astronomer Bill Longo took the image above from his observatory outside Toronto. It’s a stack of eight 30-second exposures for a total of four minutes using a Canon T3 camera and a 6.5mm lens.

It shows the night sky facing west, with the bright winter stars of Auriga and Gemini setting, with the amazingly bright planet Jupiter punctuating the twins’ belly. And that bright streak seemingly bisecting Jupiter? Why, that’s just the International Space Station moving across the sky, its 100-meter length reflecting sunlight down to Earth.

And if you look very carefully, just under the ISS trail is a much fainter one: That’s the SpaceX Dragon capsule chasing down the station. This picture was taken on April 19, 2014, just hours before the private spaceship met up with ISS and was successfully grappled to its berthing point. Longo provides an annotated version of the picture that’s helpful:

annotated version of above photo

Photo by Bill Longo, used by permission

Imagine! Six astronauts from around the world are in that bright streak, and were about to grapple an American spacecraft using a robotic arm built in Canada, so they could bring aboard a new round of scientific experiments, food, and supplies for their stay on board a working space station that’s been in orbit around our fair world for more than 5600 days. And it’s bright enough to not only be seen from the ground, but easily seen, and photographed with equipment you can pick up at a local store.

You can keep your flying cars and hoverboards. We live in the future, now, and all you have to do to prove it is go outside look up.

Tip o’ the lens cap to Bill Longo for sending me his photo.

April 20 2014 7:30 AM

Happy Easter SUN Day!

Today is Easter Sunday, a Christian holiday. It actually has a tie-in with astronomy, since it’s celebrated on the first Sunday after the first full Moon after the March equinox. The equinox was March 20, and the full Moon was Monday (during the lunar eclipse, not so coincidentally), so here we are.

As is the case with most holidays in America, there’s a secular component to it as well. In this case, the Easter Bunny (which originated in Germany, incidentally) started out with religious connotations, but now resembles more of a lagomorphic Santa Claus.


Whatever the origins, and whatever your beliefs, I think we can all agree that it’s fun to bite the ears off a chocolate bunny first (and/or perform hideous experiments on Peeps). So with an eye toward the astronomy and a tongue firmly in cheek, I present to you a picture of the Sun taken by astrophotographer Göran Strand:

© Fotograf Göran Strand
Wascally, isn't it? Click to lepusenate.

Photo by Göran Strand

What you’re seeing there is the edge of the Sun to the upper right, and a detached prominence to the lower left. A prominence is a huge blast of solar gas blown off the Sun by intense magnetic fields; usually these are connected to the Sun’s surface but sometimes become detached. It’s almost as if it…

[takes off sunglasses]

… hopped off the Sun.

Also, to give you an idea of its size, Strand included a picture of the Earth … the shape of which he changed to match the theme.

Or maybe Strand is a Heinlein fan. After all, it was he who once wrote, “The Earth is just too small and fragile a basket for the human race to keep all its eggs in it.”

That’s a fine sentiment for any season.

Note: In the interest of full disclosure, Strand took this photo on Sept. 4, 2013. But how could I resist running it today?

April 19 2014 7:30 AM

That’s No Moon … Well, Actually, Yeah It Is

lunar eclipse laser
Now witness the firepower of this fully armed and operational lunar ranging station! Click to midichlorianate.

Photo by Dan Long, used by permission

So there’s a picture you don’t see every day. Clearly, Vader’s forces were not at all happy about the lunar eclipse. 

I know, it really does look like the Moon was shooting out a laser at a passing ship, but that’s an illusion: In fact, that laser is hitting the Moon, and it was sent from Earth.


While you and I were busy watching the total lunar eclipse on Monday, a bunch of astronomers were zapping it with high-powered lasers. They do this every now and again to find out exactly how far away the Moon is (and to provide yet another test of relativity).

Apollo astronauts left a series of retroreflectors there, devices that are designed to reflect light back in exactly the same path it came in. If you shoot a retroreflector with a laser, the beam will come back directly at you. Over the course of 800,000 kilometers (500,000 miles) to the Moon and back the beam spreads out a lot, so a telescope is used to collect the photons from the laser.

Since we know the speed of light very accurately, the time it takes for the beam to hit the Moon and come back tells us its distance. Think of it this way: If you are traveling at exactly 100 kilometers per hour, and you drive for exactly one hour, you know you drove 100 kilometers. Same thing here, but the car is a photon, the speed is the speed of light, and the distance is a wee bit more then you’d go for a family outing.

In this case, the retroreflector was left by the Apollo 15 team. I knew this right away! How? Because this:

Apollo landing sites
Close-up of the laser shot (left) compared to a map of the Moon showing the Apollo 15 landing site (right; Apollo 17 is also listed).

Photo by Dan Long; Soerfm/wikipedia

Apollo 15 landed on the very eastern edge of Mare Imbrium (the large dark circle; actually a lava plain), near the border with Mare Serenitatis. As you can see, the beam converges right at the Apollo 15 spot. I know it looks like the beam is coming from there, but that’s perspective for you! The beam appears to get smaller with distance, and your eye can’t tell if it’s getting smaller as it heads away, or getting bigger as it comes closer.

Astronomers have been measuring the Moon’s distance for many years, and it’s from that we’ve learned the Moon is moving away from the Earth by about 4 centimeters per year due to the complicated interaction with Earth’s gravity. But today I learned something about this: During a full Moon, the amount of light reflected back from the Moon drops. This was a mystery for quite some time, but it turns out that’s due to the way the mirrors there are set up; the Sun shines down them and heats them up, and they lose their efficiency at reflecting light back to us. During an eclipse, though, the Earth blocks the Sun during the full Moon, so the mirrors don’t heat up. They reflect light back to us just fine, proving that solar heating was the problem.

It’s funny to think that while I was collecting photons to make photos and video of the Moon, astronomers a thousand kilometers south of me were sending photons to the Moon … and getting them back.

Tip o’ the X-Wing to Dan Long for letting me use his photo, and to APOD, where I first saw it. I'll note this is at least the fourth time I've used a variation of this headline, and it's funny every flippin' time.

Correction, April 20, 2014: I had originally attributed the photo incorrectly to Tom Murphy, who works on the ranging experiment.

April 18 2014 9:07 PM

Incredible: SpaceX Dragon Capsule Video Taken From the Ground!

Update, April 19 at 15:00 UTC: Several people on Twitter have pointed out that what is seen in this video is most likely not the capsule and deployed arrays, but actually the upper stage of the Falcon 9 rocket and the ejected solar panel covers. That does seem likely to me given the scale of the objects, so I have sent Legault an email asking him about it, and I will update this post again when I know more.

Correction, April 19 at 15:15 UTC: Aha! Yes, I do now think what we are seeing here is the upper stage of the Falcon 9, the Dragon capsule, and the two solar panel covers (used to protect the Dragon's panels during launch, and which are ejected before the panels are deployed). What I somehow missed at the end of the video are the silhouettes of trees in the distance. That gives a sense of scale to the video; the Dragon capsule itself plus the solar panels would be far smaller than seen here. Also, around 30 seconds in you can see the stars of the Big Dipper in the background, showing the field of view of this video is far larger than I had originally supposed.


So to be clear, this is NOT just the capsule and solar panels, it is a larger set of objects that are physically separated in space by quite a bit, making it much easier to photograph them. This is still a cool video, but it isn't the technical achievement I first assumed. I have struck through the original text below and added the correct info.

Thierry Legault is a gifted astrophotographer renowned for his footage of the International Space Station and (once upon a time) the Space Shuttle that he takes through his telescope. His ability to capture these rapidly moving objects is nothing short of spectacular, and I always think there's no way he can top what he's already done.

Then I see this: Video of the SpaceX Dragon capsule in orbit a mere 25 minutes after launch!

Incredible. This is seriously amazing work; being able to spot the capsule, get it framed up, and then to track it by hand as it glides over France less than a half hour after launch? Holy wow. You can actually just make out the capsule itself, and the extended solar panels on either side (those power the Dragon for the two or so days it takes for it to catch up to the space station). To give you a sense of scale, the capsule is 7.2 meters (24 feet) long and 3.7 meters (12 feet) wide. The panels are about 16.5 meters (55 feet) across. It was roughly 370 km (230 miles) above the Earth's surface when he shot this.

What you're seeing here is wide-angle footage, showing the upper stage of the Falcon 9, the Dragon capsule, and the ejected solar panel covers moving along together in orbit around the Earth. This was taken a few minutes after the capsule separated from the rocket upper stage, so all the individual things you see here were still near each other in space. Over the next two days the capsule itself will "catch up" the space station and be grappled on Sunday.

So yeah Legault is the best. I've written about his work, many, many times; go read it. Trust me here: You'll be astonished at what people can do when they're at the top of their game.

Congrats to Thierry for this achievement, and to SpaceX for another successful launch!