Tag: aurorae

Astonishing all-sky aurora time lapse video

By Phil Plait | October 15, 2012 7:00 am

I have got to get to Yellowknife, in Canada. They seem to get spectacular aurorae all the time there!

A few days ago I posted an aurora picture taken by Stéphane Guisard. Well, in October he was up in Yellowknife, and using a special camera he took an all-night all-sky time lapse video of the aurorae as it flickered and snapped across the sky. It’s magical:

Holy wow. Seriously, make this full screen. The slowly-moving stars of the Big Dipper and other constellations take a back seat (nearly literally) to the eerie green and red glowing ribbons created when the Earth’s magnetic field fires subatomic particles down into our atmosphere. Of course, when the three-week-old Moon rises, it dominates the scene, but not for long. The aurorae draw the eye, and it’s impossible to look away. Even the towering Milky Way wheeling around the sky couldn’t distract me from the lights for long.

I also love how the clouds stream in, and it gets a bit confusing distinguishing them from the aurorae. And finally, as the video draws to a close you can see Venus hanging just behind the sickle of Leo’s head, a sure sign the Sun won’t be long to rise. And on cue it does, lighting the sky and washing away the glory of the magnetic storm going on overhead.

Stéphane has more aurora shots on his site, and tons more amazing sky images, too. Go see.


Related Posts:

- Up, up, and aurora!
- Time lapse: Within Two Worlds
- Lapland lights
- Surreal Arctic time lapse

CATEGORIZED UNDER: Astronomy, Cool stuff, Pretty pictures

The 50th anniversary of Starfish Prime: the nuke that shook the world

By Phil Plait | July 9, 2012 6:05 am

On July 9, 1962 — 50 years ago today — the United States detonated a nuclear weapon high above the Pacific Ocean. Designated Starfish Prime, it was part of a dangerous series of high-altitude nuclear bomb tests at the height of the Cold War. Its immediate effects were felt for thousands of kilometers, but it would also have a far-reaching aftermath that still touches us today.

In 1958, the Soviet Union called for a ban on atmospheric tests of nuclear weapons, and went so far as to unilaterally stop such testing. Under external political pressure, the US acquiesced. However, in late 1961 political pressures internal to the USSR forced Khrushchev to break the moratorium, and the Soviets began testing once again. So, again under pressure, the US responded with tests of their own.

It was a scary time to live in.

The US, worried that a Soviet nuclear bomb detonated in space could damage or destroy US intercontinental missiles, set up a series of high-altitude weapons tests called Project Fishbowl (itself part of the larger Operation Dominic) to find out for themselves what happens when nuclear weapons are detonated in space. High-altitude tests had been done before, but they were hastily set up and the results inconclusive. Fishbowl was created to take a more rigorous scientific approach.


Boom! Goes the dynamite

On July 9, 1962, the US launched a Thor missile from Johnston island, an atoll about 1500 kilometers (900 miles) southwest of Hawaii. The missile arced up to a height of over 1100 km (660 miles), then came back down. At the preprogrammed height of 400 km (240 miles), just seconds after 09:00 UTC, the 1.4 megaton nuclear warhead detonated.

And all hell broke loose.

1.4 megatons is the equivalent of 1.4 million tons of TNT exploding. However, nuclear weapons are fundamentally different from simple chemical explosives. TNT releases its energy in the form of heat and light. Nukes also generate heat and light, plus vast amounts of X-rays and gamma rays – high-energy forms of light – as well as subatomic particles like electrons and heavy ions.

When Starfish prime exploded, the effects were devastating. Here’s a video showing actual footage from the test, 50 years ago today:

As you can see, the explosion was roughly spherical; the shock wave expanding in all directions roughly equally since there is essentially no atmosphere at that height. Another video has many more views of the test; I’ve linked it directly to those sequences, but if you start at the beginning it’s actually an hour-long documentary on the test.


Nuke ‘em ’til they glow

Read More

Surreal Arctic time lapse

By Phil Plait | June 25, 2012 7:00 am

Oh, wow. We’re having a heat wave here in Boulder — which isn’t helping the fire situation — so I’m really glad I watched this time lapse video by Tor Even Mathisen. It is, quite literally, cool.

He filmed this in Tromsø (specifically Kvaløya and Tromsøya), in northern Norway, which is apparently a mecca for aurorae (see Related Posts below). Mathisen is an editor and cameraman for Norwegian Broadcasting, and clearly has an excellent eye for the sky. He has another aurora video he shot in 2010.

This is exactly what I needed as temperatures here push 40°C. It’s nice to know that while we’re sizzling here, the atmosphere is sizzling with cold light elsewhere.

Tip o’ the parka hood to John Markus Bjørndalen.


Related Posts:

- Fire, water, and ice
- Real time footage of aurora shows them dancing and shimmering
- Will you see the lights tonight?
- The softly glowing night sky

CATEGORIZED UNDER: Astronomy, Pretty pictures

What a dramatic sunspot!

By Phil Plait | June 14, 2012 12:07 pm

Active sunspots are pretty dramatic all by themselves, but a little over-the-top music can’t hurt.

This spot has been spitting out some low-level activity, but the Sun is tricksy. We’ll see if we get some bigger ones as this thing rotates in our direction over the next few days. Be on alert for aurorae!

[Footage by NASA's Solar Dynamics Observatory]


Related Posts:

- GORGEOUS solar eruption!
- The Sun decided to blow off a little steam today. Twice.
- The Sun’s angry red spot
- HD footage of last night’s flare

CATEGORIZED UNDER: Astronomy, Cool stuff, NASA

The green fire of the aurora, seen from space

By Phil Plait | April 3, 2012 6:00 am

On March 4, 2012, the International Space Station passed over the Indian Ocean. Solar activity was high, and a gorgeous aurora raged in Earth’s upper atmosphere, yet still below the astronauts. On board the ISS, an astronaut took a series of still photos which were later put together into this video:

[Set the resolution to hi-def to really see the detail.]

Isn’t that lovely? I added the music (Supernatural by Kevin MacLeod at incompetech.com). Did you spot the moving light, traveling from left to right just as the video begins? That’s almost certainly another satellite, moving along its own orbit hundreds or even thousands of kilometers away.

I’ve written about aurorae (like here) and this method of time lapse photography many times; check out Related Posts below. With the Sun still being tempestuous, expect to see lots more gorgeous photography of our active geomagnetic field over the coming months!

Tip o’ the spacesuit visor: Remi Boucher. Credits: Image Science and Analysis Laboratory, NASA-Johnson Space Center. "The Gateway to Astronaut Photography of Earth." Here’s the original footage. Music: Kevin Macleod, Incompetech.com.


Related Posts:

- JAW DROPPING Space Station time lapse!
- Flying around the Earth
- The stars, from orbit
- Real time footage of aurora shows them dancing and shimmering

The rocket, the laser, and the northern lights

By Phil Plait | February 26, 2012 7:00 am

Some pictures just have it all. Like, say, a rocket and a laser and an aurora:

OK, that’s awesome. All it needs is a rampaging T-Rex to be the greatest single picture ever taken. [Click to enalfvénate.]

So what you’re seeing here is a wide-angle lens time exposure of a rocket launch on February 18, 2012, from Fairbanks Alaska at the Poker Flat Research Range. The aurorae are obvious enough; they’re the green glow in the sky. The bright streak is the rocket going up, and the pink hook halfway up is the first stage dropping away — note how the streak dims from the ground up to that point, then brightens again when the second stage ignited.

The green streak on the left is a laser being shot into the sky. Lasers excite (give energy to) atoms and molecules in the atmosphere, and that can be used to measure what’s going on up there. The beam appears to curve because this is a wide angle lens which distorts the geometry of the image.

So why the launch? On board the rocket was the Magnetosphere-Ionosphere Coupling in the Alfvén resonator (MICA) mission, designed to measure the magnetic and electric fields high above the Earth during an aurora — so it’s no coincidence that you’re seeing the northern lights here. Alfvén waves are a way for magnetic fields to move energy around, and they’re generated in certain kinds of aurorae. By measuring them with MICA, we can learn more about how the Sun’s magnetically-driven interacts with Earth’s own magnetic field, producing aurorae. And it’s a good time to do this: the Sun has been spitting out lots of energy lately, which has been generating aurorae left and right. As we head into the peak of the current solar cycle — sometime next year, probably — it’ll be the green golden age for studying how it affects the Earth.

Image credit: Lee Wingfield, NASA Wallops

CATEGORIZED UNDER: Cool stuff, Pretty pictures, Science

Holy aurora

By Phil Plait | February 6, 2012 7:58 pm

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

CATEGORIZED UNDER: Astronomy, Pretty pictures
MORE ABOUT: aurorae, time lapse

Real time footage of aurora shows them dancing and shimmering

By Phil Plait | January 28, 2012 10:56 pm

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 not like solid curtains of material are flapping. The lights are caused by atoms in the upper atmosphere getting hit by subatomic particles blasted out by the Sun, caught by our Earth’s magnetic field, and funneled down into our air. These particles dump energy into the atoms, moving the electrons up in energy (called excitation). The electrons then jump back down, emitting light in the process (de-excitation). As I said in an earlier post, it’s like needing energy to jump up stairs, but releasing it as you jump down.

Different atoms have different energy levels for the electrons — think of it as more or less spacing vertically between steps in a staircase — so the energy emitted is different, resulting in different colors emitted. That’s why we see green, red, purple… they come mostly from oxygen and nitrogen in the air. So as the magnetic field fluctuates, the particles are sent shooting down in different places, giving the appearance of motion while the atoms themselves don’t move.

The physics is complex and interesting, but the beauty of these lights is, to use another term, magical. Not in the fantasy sense, but in the sense of the emotional response we have to them. They are simply breathtaking in these videos, and are a wonderful by-product of our tempestuous Sun.

Tip o’ the lens cap to sunspotter.


Related posts:

- Two lovely aurora time lapse videos
- Time lapse: The Aurora
- Water falls, moonbow shines, aurorae glow
- JAW DROPPING Space Station time lapse!

Two lovely aurora time lapse videos

By Phil Plait | January 25, 2012 2:54 pm

The solar storm that impacted Earth Tuesday produced a lot of auroral activity, though it’s hard to say if it was really that much stronger than usual. Still, any aurora is better than none… and I have two videos to show you!

The first was taken on January 22, and shows the effects of an earlier wave of subatomic particles spat out by the Sun. It was made in Birtavarre, Norway by Ørjan Bertelsen, who put together 1600 exposures to make it:

It’s amazing to get the three-dimensional effect as the sheets of glowing atmospheric molecules pass overhead, and you’re seeing them nearly edge-on. And I love picking out familiar constellations in videos like that; did you see Leo, Gemini, Cancer, and Taurus?

The second video was shot in Abisko National Park, Sweden, by Chad Blakley, and all I can think of as I watch it is how cold those people must have been!

As I mentioned in a radio interview on Tuesday, I’ve never seen a bright aurora. Once in Maryland I saw a reddish glow to the extreme north during a particularly big display, but that’s really about it. Someday, though, I’ll get a chance. As the Sun gets more active over the next two years I may very well finally see these magnificent light shows. After writing about them so much, I think I’ve earned it.

Tip o’ the parka hood to John Markus Bjørndalen.


Related posts:

- The Sun aims a storm right at Earth: expect aurorae tonight!
- Will you see the lights tonight?
- Time lapse: The Aurora
- JAW DROPPING Space Station time lapse!
- Stunning Finnish aurora time lapse

CATEGORIZED UNDER: Pretty pictures
MORE ABOUT: aurorae, time lapse

Will you see the lights tonight?

By Phil Plait | January 24, 2012 11:45 am

The solar storm that erupted from the Sun yesterday reached the Earth today at about 15:00 UTC (10:00 a.m. Eastern US time). The wave of subatomic particles has been impacting the Earth’s magnetic field, and we’re starting to see some auroral activity:

Isn’t that lovely? That was taken at 18:00 UTC today from a webcam in Abisko, Sweden. Can you see the handle of the Big Dipper right below the green curtain? [More aurora webcam sites are listed below.]

The two biggest questions I’m getting on Twitter and Google+ are 1) is there any danger to this storm, and b) can I see the aurora from [my location]?

First, no, we’re not in any danger from this event. Even though it sounds terrifying — an explosion the equivalent of billions of nuclear weapons launching hundreds of millions of tons of subatomic particles Earthward at speeds of million of kilometers per hour! — we’re pretty well protected down here on the surface. The Earth’s magnetic field catches the particles, and most of those get dumped harmlessly in our upper atmosphere. That can create the aurora displays, but won’t dose everyone with radiation and give them superpowers.

Sorry. [UPDATE (19:00 UTC): a ground current surge was reported in Sweden, but so far that's the only physical impact I've heard of.]

But the aurorae are pretty cool, and that brings us to the second question. The answer depends on where you are, and when it’s dark out. As I write this, activity is on the rise. Here are some live webcams for aurorae, some of which are showing spectacular activity! Note they only show views when it’s nighttime locally:

Lapland

Fairbanks, Alaska

Yellowknife, Canada

Tromso, Norway

As for seeing them wherever you are, that’s tough to say. The Geophysical Institute has a map showing predicted activity for North America, for example, and NOAA’s Space Weather Prediction Center has a continuously updated map showing auroral activity for both hemispheres. Universe Today has a guide on how to see the aurorae, and Astronomy magazine has a discussion of aurorae, too.

I’m getting conflicting info on potential aurorae tonight; the webcams in Scandinavia listed above are showing strong (and gorgeous) activity, but the prediction for Canada and the US appear moderate at best. But don’t let that discourage you! If you have clear skies, go outside once it’s good and dark and take a look. Even if there’s no aurora, you can see Venus and the thin crescent Moon to the west right after sunset, and that’s always a plus. And if things perk up, you might get a nice light show to the north, too!


Related posts:

- The Sun aims a storm right at Earth: expect aurorae tonight!
- Time lapse: The Aurora
- JAW DROPPING Space Station time lapse!
- Stunning Finnish aurora time lapse

CATEGORIZED UNDER: Astronomy, Cool stuff, Pretty pictures
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