Bad Astronomy » Astronomy

The staring eye of a crescent moon

Phil Plait — Fri, 10 Feb 2012 17:39:56 +0000

Sometimes, the images from the Cassini Saturn probe are so cool it’s tempting just to post them and say, "Look at THAT!"

See what I mean? [Click to gigantesenate.]

But of course, I can’t just leave it at that. This image, taken on January 4, 2012, is a bit different than most. Sure, we see Saturn’s magnificent rings, nearly edge on from this perspective. And we’ve seen this icy moon Enceladus many, many times (see Related Posts below for tons more pictures). Look at the bottom of the moon: see those fuzzy streaks? Those are geysers of water spewing from cracks in the moon’s south pole! Cassini has been studying them intently ever since they were discovered; they are proof that liquid water exists under the surface of Enceladus, though it’s still being argued over whether it’s in pockets, like lakes, or the whole moon has an ocean of water under the surface.

Despite all that, I keep getting drawn to the crescent shape itself. We can never see that from Earth. Saturn is much farther out from the Sun than we are, and geometry demands that from ...

When the Moon hits your apse in a way-cool time lapse

Phil Plait — Thu, 09 Feb 2012 18:00:10 +0000

Photographer Maik Thomas posted this time lapse video on Google+, and it made me chuckle. The bright object is the Moon, and as it sets it turns red, looking like a missile from space curving right into a church.

I love the star trails effect. It’s just a way of adding the individual frames together to show motion, but it does give the video an oddly other-world feel to it. And in this case it really makes the Moon look like some sort of re-entering rocket!

Related posts:

- Star Light, People Bright
- Alps lapse
- The stars above, the luminescence below
- The lines in the sky are stars

Funhouse galaxy

Phil Plait — Wed, 08 Feb 2012 14:00:10 +0000

Sometimes, I like to think of a photon of light as a car on a road. As the road dips and curves, a car has to follow that path, dipping and curving as well. It might be weird to think of space as curving, but it does. Gravity from massive objects warps space, and a beam of light moving through that curved space curves along with it.

This is the principle behind what’s called gravitational lensing. A beam of light passing by an object — a big galaxy, say, or a cluster of galaxies — bends one way. A beam headed in a slightly different direction bends a slightly different way. This can really mess with what we see… which I can prove! Check this out: a Hubble image of the galaxy RCSGA 032727-13260.

What a mess! All those arcs and blue smudges are images of that one galaxy. The light from that galaxy traveled nearly 10 billion light years to get here! But when it was halfway here, that light passed by the big cluster of galaxies — the red fuzzballs — in the middle ...

Science Getaways: Update

Phil Plait — Tue, 07 Feb 2012 16:36:40 +0000

I love science. OK, duh, but I really do. And when I go on vacation, I can’t help but see science everywhere, and in every case it makes the trip more fun for me. Seeing local geology, biology, how the stars might look different at a different latitude… it adds to the vacations, makes it better.

That’s why my wife and I started a company called Science Getaways. We figured there are lots of other folks out there like us who would really enjoy taking a vacation that has bonus science added in. Our first planned trip is to a gorgeous Colorado dude ranch called C Lazy U. Besides the usual amenities of such a place — horseback riding, great food, spectacular views of the Rocky Mountains — we’re adding SCIENCE! And scientists: we have a geologist, a biologist, and an astronomer — hey, me! — who will be on hand to give talks about the local nature scene, and then we’ll take hikes to put that new-found knowledge to practical use. I’ll be running a stargazing session every evening with my new 8" ...

Exoplanet in a triple star system smack dab in the habitable zone

Phil Plait — Tue, 07 Feb 2012 14:00:54 +0000

In the race to find the weirdest planet orbiting another star, we may have a front runner: GJ 667Cc, a super-Earth orbiting one star in a triple system that’s actually relatively closeby. And oh yeah: it just so happens to be in just the right spot to be potentially inhabitable!

Of course, I have some caveats, so don’t get too excited. But this is a weird and pretty cool one!

GJ 667 is a triple star system that’s right in our back yard as these things go: it’s only about 22 light years away, making it one of the closest star systems in the sky. It’s composed of two stars a bit smaller and cooler than the Sun which orbit each other closely, and a third, smaller star orbiting the pair about 35 billion km (20 billion miles) out. Stars in multiple systems get capital letters to distinguish them, so the two in the binary are GJ 667 A and B, and the third one is GJ 667C.

That third star is the interesting one. It’s a cool, red M dwarf with about a third the diameter of the ...

Holy aurora

Phil Plait — Tue, 07 Feb 2012 02:58:26 +0000

I really don’t think I need to add anything to this. Set it to HD, make it full screen, and turn the sound up.

Tip o’ the magnetometer to Tom Lowe, aka Timescapes.

Related posts:

- Two lovely aurora time lapse videos
- Real time footage of aurora shows them dancing and shimmering
- Time lapse: The Aurora
- Awesome timelapse video: Rapture

An astronomer’s paradise

Phil Plait — Sun, 05 Feb 2012 14:00:39 +0000

Cerro Paranal, in the high, dry, Atacama desert in Chile, is where some of the best astronomy in the world is done. It’s graced with incredibly dark and steady skies, and a view of the southern hemisphere skies that, frankly, makes me jealous.

So it’s hard to argue with the title of this short time lapse video, An Astronomer’s Paradise:

This was taken by photographer Babak Tafreshi, who alerted me that he had put it online. Watch it to 1:30 in if only to watch Orion rise — upside down, to my northern hemisphere bias! — with colors and texture that are simply stunning.

Isn’t that awesome? And then a few seconds later, he shows a still image of the great Carina Nebula with the four domes of the Very Large Telescope Interferometer silhouetted against the sky. You can get a better look at that at The World At Night website, which has amazing shots of the sky.

I hope someday to make a trip to this part of the world. To see this for myself…

Credit: Babak Tafreshi

Space caturday

Phil Plait — Sat, 04 Feb 2012 14:00:54 +0000

This is cute and all, but I was debating whether to run it on the blog or not when I got to the 1:05 mark or so, and decided to go ahead. Why? Watch:

Did you get the joke?

It’s a Chandra X-ray Observatory image in the background if that helps. Note the cat.

Also, the next shot shown of a cat batting at Io was also pretty funny.

They did miss a sure bet, though: Cat’s Eye, and the Cat’s Paw nebula. Neither of which, I’ll note, is in Leo.

Video of the lunar far side from GRAIL/Ebb

Phil Plait — Fri, 03 Feb 2012 17:49:19 +0000

This is so cool: NASA’s twin GRAIL spacecraft (now named Ebb and Flow) have cameras on board to take images of the lunar surface, and an animation has been put together of Ebb’s view of the Moon’s far side!

Pretty neat. I love the wide-angle view; the individual images were taken while Ebb was still over a thousand kilometers from the Moon. The huge circular feature you can see on the right 30 seconds into the video is Orientale Basin, an impact so huge it must’ve lit up the solar system a few billion years ago. That basin is nearly 1000 km (600 miles) across! See the LRO image below for a clearer view, and click it for more info.

I’m really looking forward to seeing what will be done with these cameras. As Principal Investigator Maria Zuber explains in the video, they were installed specifically for educational purposes, and kids all over America will get a chance to examine the data. I love this idea, since it means these children will be invested in the project itself, and remember it for their whole lives. It’s a fantastic idea.

In the dark abyss, a slightly warped mirror on the Milky Way

Phil Plait — Fri, 03 Feb 2012 14:00:31 +0000

There is just something wonderful when Hubble points to nearby spiral galaxies. Sprawling and detailed, we get both great resolution on smaller features as well as a jaw-dropping overview of a grand spiral… like, say, NGC 1073:

Yeah, I know. [Click to galactinate -- I had to shrink it to fit here, and it lost a lot of the coolness when I did -- or grab the 3900 x 3000 pixel version.]

NGC 1073 is a decent-sized spiral galaxy about 60 million light years away. It’s actually part of a small, tight group of galaxies many of which are far more famous (like NGC 1068). But 1073 is important because of a simple property: it looks like us.

While it’s not a perfect match, NGC 1073 does bear an interesting resemblance to our Milky Way galaxy (UGC 12158 looks more like our galaxy, but is far bigger, for example). Both have large, rectangular bars going across their centers. Bars are a bit odd, since you’d expect the arms just to wind all the way down to ...

Q&BA: Pound for pound, are humans hotter than the Sun?

Phil Plait — Thu, 02 Feb 2012 18:19:08 +0000

[Note: Every week I hold a live video chat on Google+ where I answer questions from readers. I call it Q&BA, and when I get a question that stands alone, I'll make it its own video. ]

Every now and again, I hear this urban legend that pound for pound, the human body is actually hotter (or has more energy) than the Sun. I got this question in a recent Q&BA video chat session, so I tackled it. The answer is pretty interesting, and depends on how you ask the question!

I actually wrote about this legend on the blog a while back, and I show all the math. I really like this question, since it has a straightforward answer that makes it seem wrong, but then if you look at it more carefully the answer is a little trickier. And even in the video and that other post, it’s not really a complete answer; if you read the comments on the post you’ll see people arguing over it.

That’s really the best kind of question: the ones that keep on going! There’s ...

Give Pluto your stamp of approval

Phil Plait — Wed, 01 Feb 2012 18:00:32 +0000

In 2015, NASA’s New Horizons spacecraft will zip past Pluto, giving us our first close-up view of this tiny world.

The team behind the space probe have a nice idea to help raise awareness of it: make a new US Post Office stamp commemorating it. My friend Dan Durda, both an accomplished astronomer and artist, created this lovely design of the stamp:

[Click to enhadesenate. Note: the word "Forever" means the stamp is always good for first class postage, and is crossed out here to prevent forgery.]

It shows the spacecraft going by Pluto and its (relatively) freakishly large moon Charon. I like how he didn’t go for photorealism, but instead used an oil paint-like feel for it. The stamp is meant as a followup — I might even say send-up — of a US stamp issued in 1990 about Pluto that has the label "Not Yet Explored".

I like this stamp! I’d love to see it made official, too. Alan Stern, the head guy for the mission, created a petition to help that along. It takes more than just a nice stamp design ...

Amazing moonset video taken from space!

Phil Plait — Wed, 01 Feb 2012 01:32:31 +0000

Thanks to astronaut Ron Garan on Google+, I was alerted to some amazing footage of the Moon setting as seen by astronauts on board the International Space Station. I uploaded it to YouTube and added some comments to show you something really cool…

[Set it to high-def and make it full screen!]

Astonishing, isn’t it? As the Moon sets, you’re seeing it through thicker and thicker air. The air acts like a lens, bending the light upward. The part of the Moon nearer the Earth’s limb gets bent up more, so the Moon looks like it’s getting flattened. Watch it again; the top of the Moon doesn’t appear to be affected much. It looks more like the bottom slows down and the top pushes into it. You can read about this effect in more detail in an earlier blog post.

Weirdly, as I watched the video, it looked very much like the whole Moon was shrinking as it set, as if it were receding rapidly. When I saw that I knew intuitively that couldn’t be real; the ISS is only moving a few thousand kilometers ...

Does the planet Fomalhaut b exist?

Phil Plait — Tue, 31 Jan 2012 14:00:34 +0000

Well, this is depressing: Fomalhaut b may not exist.

Fomalhaut is one of the brightest stars in the sky, and is only about 25 light years away — that’s close, on a cosmic scale. It’s young, not more than a few hundred million years old, and surrounded by a vast ring of dust, leftover from the formation of the star itself. The ring is about 20 billion km (12 billion miles) in radius, and has a sharp inner edge.

That last bit is important: the easiest way we know to make the inside edge that well-defined is if a planet is orbiting the star just inside the ring. Its gravity would draw in particles, sculpting what would otherwise be a fuzzy boundary into a clean-cut ring. Not only that, but the ring is off-center; again, that’s likely due to the gravitational influence of a planet.

In 2008, astronomers announced they had found that planet: it appeared in two different Hubble Space Telescope images (shown above; click to embiggen) separated by two years. During that time, it had moved a little bit, by just what you’d expect for a planet ...

Strange yet cool VLA time lapse video

Phil Plait — Mon, 30 Jan 2012 17:20:30 +0000

I’m sure what I can say about this, except that it’s oddly engaging.

I’ve been to VLA*, many years ago to do a video for an educational activity, and I don’t recall seeing them behave quite this way. Maybe I should’ve waited until night time.

Tip o’ the side lobe to my pal and science nerd Jeri Ryan on Google+.

* Yes, I know the name was recently changed to the Karl G. Jansky Very Large Array, but I’ll be honest: I don’t like the new name. If they had just called it the Jansky Array that’d be fine. But if the old name was clunky, it had an easy acronym. Now the name is longer and the acronym harder! So to me, it’ll always be the VLA. And get off my lawn.

Dione and Mimas have a mutual event

Phil Plait — Mon, 30 Jan 2012 14:00:08 +0000

As Cassini weaves its way around the multiple moons of Saturn, it’s not really a coincidence when one gets in the way of another. As a matter of fact, it’s a guarantee. These are called mutual events, and when Cassini dove past Dione, it saw this terrific view of Mimas peeking out from behind it:

Nifty, huh? [Click to encronosenate.]

Dione is nearly 3 times larger than Mimas (1100 versus 400 km wide), but Mimas was also more than 6 times farther away, making Dione loom nearly 20 times larger in this shot. I like how you can’t really see the unlit side of Dione, but Mimas marks it pretty well, sliced in half by the edge of the larger moon.

Funny, too: I was thinking to myself that if Cassini was in position to catch this shot, then it should have also caught Mimas when it was on the other side of Dione, the lit part. Well, seek and ye shall find: I searched the Cassini raw image archive and found it! I put a small ...

Mesmerizing, towering loops of solar magnetism

Phil Plait — Sun, 29 Jan 2012 14:02:58 +0000

I know I’ve been writing about the Sun quite a bit lately, but I have a followup to yesterday’s cool video of the big solar flare… and you’re gonna like it.

I was fooling around with helioviewer.org, watching the flare in different wavelengths of light detected by NASA’s Solar Dynamics observatory, when I switched to 17.1 nanometers — in the far ultraviolet. At that wavelength, the glowing plasma that flows along the Sun’s magnetic field lines is very bright. The images were so beautiful, so incredible, I made a video animation of them, covering the time range of January 26, 2012 at midnight to January 28 at noon (UTC), which includes the huge X2 solar flare that erupted on the 27th. The video shows huge loops of magnetism on the Sun’s surface, glowing plasma flowing along them… and then 48 seconds in the flare changes everything. Watch:

Holy wow! Isn’t that awesome? Make sure you watch in in HD, and make it full screen to get the whole effect.

What you’re seeing is Active Region 1402, a sunspot cluster. This is a tangled collection of magnetic field lines piercing the surface of the Sun. Like ...

Real time footage of aurora shows them dancing and shimmering

Phil Plait — Sun, 29 Jan 2012 05:56:25 +0000

Photographer Alistair Chapman traveled to Tromso, Norway — 300 km north of the Arctic Circle — to capture video of the aurorae from the recent spate of solar storms. What he caught on camera is remarkable: shimmering, waving, dancing lights moving in real time!

[Make sure you set it to 720p; Chapman says higher-def footage is coming soon.]

That’s amazing. Aurorae video is generally done with time lapse to show the movement, which is usually slow. I’ve often wondered just how fast the movement really is; I always figured fluctuations in the solar particle density, speed, and magnetic fields would produce real-time changes in the lights, but I’d never seen anything like this! After a search of YouTube I actually found several more.

I know some people will think this is fake, and I had my skeptic hat on while watching it. Note that in most time lapse you can see the stars move; in this they don’t, indicating (unless it’s a complete fake) short periods of time during the filming. Given that, plus the existence of other video like it, I’m thinking this is real.

Mind you, the movement you’re seeing isn’t a physical motion. It’s ...

The Sun’s still blasting out flares… BIG ones

Phil Plait — Sat, 28 Jan 2012 13:35:22 +0000

Active Region 1402, the same sunspot cluster that blew out a solar flare and caused all the ruckus last week, is still being feisty: just before rotating to the other side of the Sun, it erupted in an intense, pulsing solar flare that actually was much more powerful than the one that happened last Monday. This was an X2 class flare, making it more than twice as energetic as Monday’s.

Happily, the flares were on the edge of the Sun’s disk, so the bulk of the radiation was aimed away from the Earth, but it still makes for some pretty dramatic footage. Using helioviewer.org I created a video showing about 2.3 hours of the Sun as seen by NASA’s Solar Dynamics Observatory. It shows the Sun in the extreme ultraviolet (at a wavelength of 19.3 nanometers if you wanna get geeky), where magnetic activity is seen easily. Watch the upper right corner of our friendly star… and make sure you make it HD and full screen.

Isn’t that awesome? The flare got so bright the automatic software dimmed the rest of the Sun to compensate, giving you an idea of just how powerful ...

Siriusly twinkling

Phil Plait — Fri, 27 Jan 2012 16:19:42 +0000

If you live nearly anywhere on Earth — those of you north of 73° you’re out of luck, but I’m guessing there aren’t many of you! — and look to the southeast shortly after sunset, you’ll see the figure of Orion. Follow the three belt stars to the east, and you’ll see a bright star: Sirius, the brightest star in the night sky. If it’s near the horizon, you may see it twinkling madly: flickering, dancing, perhaps even changing color.

This gave astronomer David Lynch an idea: take a time exposure of Sirius with a camera and telephoto, and purposely wiggle the mount. He tried it on January 4, 2012, and the result he got is actually quite lovely:

Isn’t that cool? As the vibrating camera caused the star to trail around, the changing colors got recorded along the track. The changing brightness of Sirius can be seen as well, as parts of the loop-de-loop fade and intensify.

The reason stars twinkle is because of our atmosphere: little blobs of air are constantly in motion. These air parcels act like lenses, and as light ...

Weekly Space Roundup for January 26, 2012

Phil Plait — Fri, 27 Jan 2012 14:05:59 +0000

Yesterday was the weekly live video Space Roundup, run by Fraser Cain from Universe Today. This week we had Pamela Gay, Alan Boyle, Nicole Gugliucci, and Ian O’Neill. We talked about the solar storm, black holes, arsenic life, Newt Gingrich, Phobos-Grunt, and answered some questions from the listeners. Here’s the video:

We do these every week on Google+ at 18:00 UTC on Thursday. Come join us!

This is a galaxy

Phil Plait — Thu, 26 Jan 2012 19:23:16 +0000

I have nothing to add to this, except to say it’s great, and I saw it because Brian Cox mentioned it on Twitter.

Oh yeah: one more thing; watch it in HD and full screen. Coooool.

Rosetta’s stunning Mars

Phil Plait — Thu, 26 Jan 2012 13:52:58 +0000

In 2007, the European Space Agency probe passed by Mars on its way to visit a comet. It used Mars for a gravity assist to help it on its way, and got close enough to take some very detailed pictures (it also passed by the asteroid Lutetia and returned amazing shots; see the gallery at the bottom of this post). That data wasn’t initially released by the mission leader (that’s fairly common in some missions), but they were finally made available late last year. My pal Emily Lakdawalla from the Planetary Society Blog grabbed a bunch of them and put together some simply amazing pictures from them, including this jaw-dropper:

Yeah. You really want to click that to Barsoomenate it. Holy dry ice polar caps!

In fact, you should go over to her blog where she gives all the details and has more incredibly cool pictures of the Red Planet as well. I don’t want to spoil her fun by giving it all away here. Go!

Credit: ESA / MPS / UPD / LAM / IAA / RSSD / INTA / UPM / DASP / IDA / processed by ...

Spectacular site for Supernova 2012A

Phil Plait — Wed, 25 Jan 2012 14:00:04 +0000

The first supernova of the year was spotted a couple of weeks ago: Supernova 2012A, in the galaxy NGC 3239 in the constellation of Leo. Adam Block of the Mount Lemmon SkyCenter took a phenomenal image of it:

[Click to corecollapsenate.]

Funny, the supernova isn’t what you’d expect; it’s not that really bright star (which is probably a star in our own galaxy that happens to be superposed on the galaxy) but instead the fainter one indicated. Images taken years ago show no sign of the new star.

The galaxy is called NGC 3239 (or Arp 263), and is a weird galaxy technically classified as irregular. Its distance isn’t well known, but it’s something like 25 million light years away or so. I imagine we’ll get a better distance determination very soon, since that’s important in understanding how much energy a supernova puts out.

The shape of the galaxy is probably the result of the collision of two separate galaxies which are still in the process of merging. The odd shape is a consequence of that. The pinkish glow is from gas clouds ...

Interview on KPCC about the flare and aurorae

Phil Plait — Wed, 25 Jan 2012 02:59:02 +0000

I was interviewed by Patt Morrison on NPR’s KPCC radio in Los Angeles today about the solar storm. It’s online for your listening pleasure, or you can grab the MP3 directly.

We talked about the event itself, how it was not nearly as strong as it was thought it would be (though still producing some aurorae and a bit of ground current in Sweden), what impacts it might have had, and what we can learn from things like this to protect ourselves in the future.

I really enjoyed this interview; Patt is knowledgeable and easy to talk to, and I hope I can be on the show in the future to talk about more astronomical events!