• 4 months ago
After Northern Lights appeared as far south as Colorado, Live Science discusses how "cannibal" coronal mass ejections (CME) are formed and what impact they have on Earth.
Transcript
00:00There are some beautiful auroras happening in the northwest of America right now.
00:04Yeah, so like NOAA scientists have given this a really, really simple explanation,
00:09and it's called a cannibal coronal mass ejection.
00:14That's the thing that's causing all of these auroras going on right now.
00:19Cannibal corona mass ejection.
00:22Yeah.
00:22That sounds a little terrifying.
00:24I mean, it's kind of funny, right?
00:25Because just as soon as we get over one kind of corona, we get hit by another.
00:28But this one, a cannibal coronal mass ejection, if I break that down for you,
00:34it's caused by sunspots.
00:36So there's a sunspot on the sun called AR2975 right now.
00:41And what it's been doing over the last, say, few days is producing up to 17 solar eruptions,
00:48two of which have headed straight towards us.
00:52Now, one of them was traveling faster than the other.
00:55It was the one that came just after the first one that was emitted.
01:01Now, when that second coronal mass ejection caught up with the first, it cannibalized it.
01:09It swept it all up into this one big wave of these charged particles,
01:14and then they all swept towards the Earth.
01:16And then when they hit it, they caused a geomagnetic storm.
01:21Where they come from in how sunspots are created is magnetic fields are created on the sun.
01:26The sun is just a giant ball of plasma.
01:29So there's loads of charged particles eddying and moving around inside the sun, across the
01:34sun's surface.
01:35Now, when you have charged particles moving, you're going to induce some magnetism there.
01:40But because magnetic field lines can't cross, and you've got all these moving particles,
01:44like this giant traffic jam of particles moving everywhere,
01:47you'll inevitably get these field lines bunched up next to each other.
01:50They'll form into these tight knots that can't escape anywhere else.
01:54And eventually, they will have to snap and release energy.
01:58Now, they release energy either in the form of a solar flare, like a bright flare of radiation,
02:03or they'll release energy in the form of like chucking out some of that plasma from the sun.
02:07What's the difference between solar flares and coronal mass ejections?
02:11So solar flares is just the bright flash that you'll see of radiation
02:16from that field line snapping that energy release.
02:19A coronal mass ejection is some of the sun's plasma soup actually being burped out of the sun.
02:26I love that phrase, plasma soup.
02:28Yeah, tasty plasma soup.
02:31I mean, pretty, but I mean, a little terrifying, right?
02:36I mean, does it affect Earth?
02:40So it does.
02:41But not in like a...
02:44So not in an always really terrible way.
02:47Most of the time, the Earth has a pretty strong magnetic field,
02:51which is really, really good news for us,
02:53because it protects us from all of these like highly energized particles
02:57that the sun has just spewed out at us.
02:59In this case, at like speeds of like 2 million miles per hour,
03:02which is just, I guess, 33 times less than the speed of light.
03:06Pretty quick.
03:07So what the Earth's magnetic field will do is it will absorb all of these particles.
03:14The energy will go into stretching out the magnetic field in space.
03:18So it's like it's kind of bunched out towards the...
03:21It gives it a long tail.
03:24And then most of those particles will gather kind of towards the poles
03:29where they will like go downwards and then energize some of the molecules in the atmosphere.
03:36And when these molecules in the atmosphere then give out light
03:41in order to kind of go down to a lower energy level,
03:44that's why we see the aurora.
03:46Now, because there's so many of these like particles coming in,
03:50you're getting auroras much lower down along the northern hemisphere
03:54than you would normally expect to see.
03:57That's a pretty...
03:59That's a nice effect there.
04:01And I know that people had already taken video from it.
04:06This is from Manitoba in Canada.
04:11Beautiful.
04:11Just absolutely beautiful.
04:13Yeah, yeah, yeah.
04:14And like I think also you could see the aurora in the U.S.
04:17certainly like as far south as Pennsylvania, Iowa and Oregon over the last few days as well.
04:23Oh, right.
04:24On spaceweather.com that you guys were sharing information from,
04:29they showed some pictures.
04:30Purple.
04:31I mean, purple.
04:33What an aura that Earth is giving off of this aurora.
04:37And when you mentioned poles,
04:41I'm like, that's why they're always up there towards the poles.
04:44We got to get closer to some poles, Ben.
04:46Yeah, yeah.
04:47But so, okay.
04:48So that's the good.
04:51How about damage?
04:53Okay, yes.
04:54So damage.
04:57So they can cause damage.
04:59So one of the most recent kind of power outages that was caused by a storm of this type
05:06was the 1989 Quebec power cut, which was caused by a geomagnetic storm.
05:11Now, most of the time,
05:13especially when it comes to people who provide like power lines and stuff,
05:16a lot of them have shielded like their power cables and things like that
05:20with a kind of Faraday cage, basically, which diverts the energy.
05:25Or they also have like other techniques that allow them to kind of siphon off excess energy
05:30that might be given to power lines by storms like this.
05:33But like that hasn't always been the case.
05:35Like, especially back in 1859,
05:38there was a really big event called the Great Carrington event,
05:41which was the largest sort of solar storm in modern human history.
05:45I'm sure there have been solar storms just as large throughout our past.
05:50But like before that point, we weren't really documenting it.
05:53We didn't have many electronics around, so we didn't really care.
05:57But in this case, the Great Carrington event fried
06:01most of the telegram systems in the US and in Europe that had been developed at the time.
06:06And it also led to auroras that could be seen around like as far south as the Caribbean.
06:13And like there were people waking up at night,
06:16thinking that it was daytime in the Caribbean
06:20because of these enormous auroras from this event.
06:23I mean, we're freaked out about it now when we see things like that.
06:26We know more, but I can't even imagine, you know, over 100 years ago.
06:30Yeah, exactly.
06:32In terms of more modern sort of phenomena that have caused more modern damage,
06:37other than the Quebec event,
06:39recently, actually, there was another geomagnetic storm
06:42that caused the downing of 40 of SpaceX's Starlink satellites.
06:48That was one thing that happened.
06:50And on top of that as well,
06:52there's a potential risk that the internet in general,
06:57especially in the United States, could be cut out by a geomagnetic storm
07:02because a lot of these cables run underwater
07:05through latitudes that would be affected by it.
07:09And you would have a geomagnetic storm.
07:12They're not shielded.
07:13So they would basically be probably quite severely affected by this.
07:16But as is the case with a lot of things and how they're done with legislation,
07:22it's like earthquakes.
07:22It doesn't often get legislated for until the worst has already happened.
07:26Yeah, that's a shame.
07:27I mean, I really like the internet.
07:29I really, I like to keep it around.
07:31This is how we get to communicate, right?
07:36But you're saying that we have protections now.
07:39So I think most power companies have already built in protections
07:44into their grids for these kind of things.
07:46It's just, yeah, you're not going to be getting any,
07:49I guess, coronal mass ejection memes in the middle of a coronal mass ejection.
07:53You have to wait a few weeks for them to fix the underwater cables.
07:57Yeah.
07:57And luckily, Earth, we have this nice electromagnetic shield, right?
08:02Already built in, otherwise we'd be goners.
08:05Yeah, it would fry us and it would also fry our atmosphere.
08:08Like a big reason why Mars doesn't have much of an atmosphere, for instance,
08:11is it doesn't really have a very active magnetic field.
08:14So all of the atmosphere, when it gets hit by this wave of hydrogen particles,
08:21like these protons, the atmosphere gets stripped away quite quickly.
08:25Poor Mars, poor Mars.
08:27Yeah.
08:28But that's why we're here, right?
08:30I mean, we are on Mars, but not yet.
08:33Not yet, not yet.
08:34Well, so is there a way to know when things like this will happen?
08:39I know we watch the sun, we have video of the sun.
08:42It seems more like after the fact.
08:46Yeah.
08:46So you get a bit of advanced warning.
08:49For instance, the Great Carrington Event is named after Richard Carrington,
08:52who spotted intense solar flares in the sky a few hours,
08:58maybe about 15 hours before the actual event hit.
09:02But the sun is quite a complex object.
09:05There's loads going on in those magnetic fields.
09:08It's still really, really hard for scientists to predict what's going on there.
09:11Yeah, if only, if only.
09:14Well, until the next major astronomical event.
09:18Thanks so much, Ben.
09:19Thank you.

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