This is my last post for the Bad Astronomy Blog on Discover Magazine. As of today – Monday, November 12, 2012 – the blog has a new home at Slate magazine.
It has been my pleasure and honor to be a Discover blogger for more than four years. Still, I remember my science teacher in third grade quoting Heraclitus to us: "Nothing is permanent except change". That’s true today, of course, and just as obviously in the Age of the Internet the velocity of that change is accelerating.
But in this case I hope the change isn’t too shocking for you, dear BABloggees. All you have to do is switch a URL in your bookmarks or update your RSS feed (to do that, just copy that link address into your feed reader). I’ll still be writing the same sort of material, I’ll still make dumb puns, and I’ll still be Tweeting, Facebooking, and GooglePlussing like mad.
To be clear: all the archives of my blog will be copied to Slate magazine, but will still have a home here at Discover. I’d be obliged if you updated links to the new archive, but old links shouldn’t break.
And so, I bid a fond adieu to Discover. What I said in my post announcing the move still holds true: I encourage everyone to read the fantastic collection of science blogs that live here, among the best such blogs in the world; fantastic company in which to be. And I hope you follow me to Slate.
It’s a big Universe out there, roomy enough for all of us. And there’s still a vast amount left to explore and understand.
Folks, it’s time. And an appropriate time: for my penultimate post here at Discover Magazine, I’ve decided to show you my tattoo.
I’ve been meaning to post this for a while, but there were a lot of behind-the-scenes issues getting permissions I won’t bore you with. But by the time I was able to post this it was so long after I got inked it seemed a little silly. Still, Discover Magazine was the reason I got it, so it seems fair and fitting to post this now. And I’ve dyeing to let y’all know anyway.
As a brief recap, a few years ago I made a bet with then-Discover Magazine CEO, Henry Donahue: if I got 2 million page views in one month, and the magazine got 5 million total, we’d both get tattoos. In March 2009 we did it! So Henry and I went about getting inked.
He got a pretty nifty Celtic fish on his shoulder. For mine, I decided to turn to you, my readers, for suggestions. And they poured in. I narrowed it down to a handful I liked, then made my decision. Henry and I thought it would be fun for me to try to get my tattoo on the TV show "L.A. Ink", so I applied. They accepted! Discover Magazine generously offered to cover my expenses, and so a little while later I was on my way to Hollywood to get myself some ink.
That’s the basic story. So, without further ado, here it is: my tattoo!
Cool, huh? It’s perfect, and just what I wanted! And how appropriate is it to get an asteroid burning up over the Earth? I know, the scale’s a bit off, but it’s a tattoo, not a scientific graphic in the Astronomical Journal. And I love the flames and the colors.
The actual clip never wound up getting aired on TLC, but they did create a fully-produced version and put it up on YouTube – they have a higher res version on the TLC site. For those of you too lazy to click, here is the YouTube video version:
The first thing to note in the video is that while I seem upbeat I was actually screaming in pain inside my head. The whole thing took just under four hours, and the last quarter of that was where Dan was going over the flames again and again, shading in all the reds and oranges. The pain was, um, astonishing.
Still, I love the end result! If you’re looking to get a full-color tattoo, you could do a lot worse than Dan Smith. He’s an excellent artist, and a friendly guy. If I were to get another tattoo – which will never ever happen – I’d want him to do it.
Thank you Henry, thank you Dan, and thank you Discover Magazine for supporting this bit of fun. It was quite a ride, and I have a nice piece of art to show for it that’ll last the rest of my life.
The Cascade range of volcanoes is pretty impressive to see from the ground. Stretching from California up to Washington, it includes famous mountains like Saint Helens, Hood, and Rainier. I’ve seen many of these while driving in the area, and they’re even cooler from an airplane.
But I have to say, the view from the International Space Station might be best.
[Click to cascadienate.]
This shot was taken from the ISS on September 20, 2012, and shows the region around Mount Shasta, a 4300 meter peak in northern California. It’s technically dormant – it erupted last in 1786. In geologically recent history it’s erupted every 600 years or so, but that’s not a precise schedule, so geologists keep an eye on it, as they do many of the peaks in the Cascades. As well they should.
To the west of the mountain (to the right in the picture, near the edge) is the much smaller Black Butte. I only point that out because you can see a highway winding around it to the right. That’s I5, a major north-south highway, and a few years back when my family lived in Northern California, I drove it on our way to and back from Oregon. Black Butte was a pretty impressive lava dome, looking exactly what you expect a volcano to look like. And looming in the distance was Shasta, but more standard mountainy looking. That appearance is, of course, quite deceiving.
I love volcanoes, and I’m fascinated by them. I’m hoping to visit some more very soon.. and I’ll have some news about that, I think, in the near future.
Image credit: NASA
Do you like volcano pictures from space too? Here’s a bunch of ‘em!
Speaking of Neil Tyson, if you’re a fan of his you’ll be pleased to know that his show, Star Talk Radio, is now going to be part of the Nerdist Channel network! Thats actually a pretty big deal; Chris Hardwick has created this juggernaut of Nerdist and it reaches a lot of folks.
The new show is essentially a video version of the radio show. Chris interviewed Neil about it for The Nerdist website. If you’re curious what it’ll be like, here’s a video of a live Star Talk interview he did with several comedians (Hodgman! Schaal!) and Mike Massamino, a NASA astronaut:
Cool, eh? And maybe I’ll have more news about this soon, too. Superman isn’t the only guy who walks around in his underwear Neil has talked to.
I love it when kids get excited enough about science to go out and do something about it. That’s why I’m digging Jeffrey Tang – who’s 10 – because he created the Astronomy For Kids podcast, where he talks about different astronomical things. The first podcast went up in February 2012 ("The Solar System") and he’s done others on Stars, the Moon, Saturn, and gravity. They’re only a few minutes long, perfect for a kid to listen to, and the ones I listened to were accurate and covered the ground pretty well. They’re also interesting and fun!
If you have a kid who likes science, I bet they’ll like this podcast. And I can see these being played in schools, too. Who better to connect with kids than another kid?
[Today is Carl Sagan’s birthday, celebrated by lovers of science and rationality around the planet. I wrote the following post last year, but I think it’s still appropriate (and I updated his age). Happy birthday, Carl. It’s a darker cosmos without you, but we still walk with the candle you lit for us.]
If Carl Sagan were still alive, he’d be 78 years old today. Perhaps he wouldn’t have been overly concerned with arbitrary time measurements, especially when based on the fickle way we define a "year", but it’s human nature to look back at such integrally-divisible dates… and Carl was very much a student of human nature.
I’ve written about him so much in the past there’s not much I can add right now, so I thought I would simply embed a video for you to watch… but which one? Where James Randi eloquently and emotionally talks about his friendship with Carl? Or the wonderful first installment of Symphony of Science using my favorite quote by Carl? Or this amazing speech about how life seeks life?
But in the end, the choice is obvious. Carl Sagan’s essay, "Pale Blue Dot", will, I think, stand the test of time, and will deservedly be considered one of the greatest passages ever written in the English language.
Happy birthday to Doctor Carl Sagan, Professor of Astronomy, scientist, skeptic, muse, and – though he may not have thought of himself this way — poet.
I’ll leave you with this, something I wrote abut Carl a while back, when asked about what his greatest legacy is:
Sagan’s insight, his gift to us, is the knowledge that we all have the ability to examine the Universe with all the power of human curiosity, and we need not retreat from the answers we find.
Of all the amazing pictures returned from the moon by the Lunar Reconnaissance Orbiter – and I may include the Apollo landing sites among them – I think my favorites are the ones showing boulders that rolled down slopes.
Did I say rolled? I mean bounced!
[Click to enselenate.]
This shot from LRO shows the floor of crater Shuckburgh E, an impact crater about 9 km (~6 miles) across. The image shows a region about 655 meters (0.4 miles) across. The crater floor here is not level; it’s tilted up from left to right, and also has contours. Boulders dislodged for some reason (a seismic event, or a nearby impact) on the right have rolled down to the left… and some actually skipped along, bouncing and bounding as they did.
The two biggest trails are dashed, indicating the boulders had a bit of a rollicking time before coming to rest. You can see both boulders at the left of the trails, where they came to a stop. Note that the sunlight is coming from the bottom of this picture, which can play tricks on perspective. I see the boulders looking almost like craters and the skidding trails they left like little mounds. If you flip the picture over it may look better to you.
As always, pictures like this are a strong reminder that even on the Moon, where time stretches long and processes are slow, changes do occur. Maybe not often, and maybe not recently, but given enough time you have to think of the Moon as a dynamic place.
Image credit: NASA/GSFC/Arizona State University
Astronomers are discovering a lot of planets these days. The official count is 800+, with thousands of more candidates (unconfirmed but suspiciously planet-like).
Right now we give them alphabet soup names. Alpha Centauri Bb. HR 8799b (through HR8799 e). And of course, everyone’s favorite, 2MASS J04414489+2301513b.
These catalog names are useful, but less than public friendly. In science fiction we get Vulcan, Psychon, Arrakis, and other cool names. So why not in real life?
The folks at Uwingu asked themselves this very thing. Uwingu (pronounced oo-WIN-goo) is an astronomy and space startup company that’s looking to fund scientific research and exploration. I wrote an intro to Uwingu back when it was soliciting funds to get initially rolling (happily, that goal was met). The idea is to sell goods and services to space enthusiasts, and use the proceeds toward doing real science. The folks in charge are professional astronomers and space scientists at the tops of their fields, people like Alan Stern and Pamela Gay. Full disclosure: I am on the Board of Advisors for Uwingu, an unpaid position, but I’d write about it and support it anyway. These are top-notch scientists behind the project.
What does this have to do with the letter and number salad that is the current state of exoplanet names? As their first foray, the folks at Uwingu decided to let people create a suggested names list for these planets. For $0.99 a pop, you can submit a name you like to the database, and for another $0.99 you can vote for your favorite in the current list. I’ll note these names are not official – they are not assigned to specific planets, and only the International Astronomical Union can make these official (and mind you, they’re the ones who so elegantly handled the Pluto not being a planet issue (yes, that’s sarcasm)). But, these names will be seen by planetary astronomers, and eventually those planets are going to need names. Why not yours?
I think this is a fun idea. There are currently nearly a hundred names in the database as I write this, but it’s expected to grow rapidly. If you think there should be a Q’onoS, Abydos, or even Alderaan – in memoriam, of course – then head over to Uwingu.
Well now, this is an interesting discovery: astronomers have found what looks like a "super-Earth" – a planet more massive than Earth but still smaller than a gas giant – orbiting a nearby star at the right distance to have liquid water on it! Given that, it might – might – be Earthlike.
This is pretty cool news. We’ve found planets like this before, but not very many! And it gets niftier: the planet has at least five siblings, all of which orbit its star closer than it does.
Now let me be clear: this is a planet candidate; it has not yet been confirmed. Reading the journal paper (PDF), though, the data look pretty good. It may yet turn out not to be real, but for the purpose of this blog post I’ll just put this caveat here, call it a planet from here on out, and fairly warned be ye, says I.
The star is called HD 40307, and it’s a bit over 40 light years away (pretty close in galactic standards, but I wouldn’t want to walk there). It’s a K2.5 dwarf, which means it’s cooler, dimmer, and smaller than the Sun, but not by much. In other words, it’s reasonably Sun-like. By coincidence, it appears ot be about the age as the Sun, too: 4.5 billion years. It was observed using HARPS, the High Accuracy Radial Velocity Planet Searcher (I know, it should be HARVPS, but that’s harvd to pronounce). This is an extremely sensitive instrument that looks for changes in the starlight as a planet (or planets) orbits a star. The gravity of the star causes the planet to orbit it, but the planet has gravity too. As it circles the star, the star makes a littler circle too (I like to think of it as two kids, one bigger than the other, clasping hands and swinging each other around; the lighter kid makes a big circle and the bigger kid makes a smaller circle). As the star makes its circle, half the time it’s approaching us and half the time it’s receding. This means its light is Doppler shifted, the same effect that makes a motorcycle engine drop in pitch as it passes you.
Massive planets tug on their star harder, so they’re easier to find this way. Also, a planet closer in has a shorter orbit, so you don’t have to look as long to find it. But in the end, by measuring just how the star is Doppler shifted, you can get the mass and orbital period of the planet. Or planets.
In this case, HD 40307 was originally observed a little while back by HARPS, and three planets were found. But the data are public, so a team of astronomers grabbed it and used a more sensitive method to extract any planetary signatures from the data. They found the three previously-seen planets easily enough, but also found three more! One of them is from a planet that has (at least) seven times the mass of the Earth, and orbits with a 198 day period. Called HD 40307g (planets are named after their host star, with a lower case letter after starting with b), it’s in the "super-Earth" range: more massive than Earth, but less than, say Neptune (which is 17 times our mass).
We don’t know how big the planet is, unfortunately. It might be dense and only a little bigger than Earth, or it could be big and puffy. But if its density and size are just so, it could easily have about the same surface gravity as Earth – that is, if you stood on it, you’d weight the same as you do now!
But the very interesting thing is that it orbits the star at a distance of about 90 million kilometers (55 million miles) – closer to its star than is is to the Sun… but that’s good! The star is fainter and cooler than the Sun, remember. In fact, at this distance, the planet is right in the star’s "habitable zone", where the temperature is about right for liquid water to exist!
That’s exciting because of the prospect for life. Now, whenever I mention this I hear from people who get all huffy and say that we don’t know you need water for life. That’s true, but look around. Water is common on Earth, and here we are. We don’t know that you need water for life, but we do know that water is abundant and we need it. We don’t know for sure of any other ways for life to form, so it makes sense to look where we understand things best. And that means liquid water.
Here’s a diagram of the system as compared to our own:
Note the scales are a bit different, so that the habitable zones of the Sun and of HD 40307 line up better (remember, HD 40307g is actually closer to its star than Earth is to the Sun – an AU is the distance of the Earth to the Sun, so HD 40307 is about 0.6 AU from its star). What makes me smile is that the new planet is actually better situated in its "Goldilocks Zone" than Earth is! That’s good news, actually: the orbit may be elliptical (the shape can’t be determined from the types of observations made) but still stay entirely in the star’s habitable zone.
And take a look at the system: the other planets all orbit closer to the star! We only have two inside Earth’s orbit in our solar system… but all five of HD 40307’s planets would fit comfortably inside Mercury’s orbit. Amazing.
So this planet – if it checks out as being real – is one of only a few we’ve found in the right location for life as we know it. And some of those we’ve found already are gas giants (though they could have big moons where life could arise). So what this shows us is that the Earth isn’t as out of the ordinary as we may have once thought: nature has lots of ways of putting planets the right distances from their stars for life.
We’re edging closer all the time to finding that big goal: an Earth-sized, Earth-like planet orbiting a Sun-like star at the right distance for life. This planet is a actually a pretty good fit, but we just don’t know enough about it (primarily its size). So I’m still waiting. And given the numbers of stars we’ve observed, and the number of planets we found, as always I have to ask: has Earth II already been observed, and the data just waiting to be uncovered?
Image credits: ESO/M. Kornmesser; Tuomi et al.
– ALPHA CENTAURI HAS A PLANET!
– Kepler confirms first planet found in the habitable zone of a Sun-like star!
– A nearby star may have more planets than we do
– Exoplanet in a triple star system, smack dab in the habitable zone
– Super-Earth exoplanet likely to be a waterworld
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And they’re right. As I wrote last night, there is much work to be done. I don’t think we can or even should put our differences aside – we need them to keep a check on runaway beliefs. But that doesn’t mean we can’t work together to move things forward.