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WHAT IS AN AURORA? - Contenido educativo

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Subido el 1 de abril de 2021 por Alicia M.

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Every second, one million tons of matter is blasted from the sun at a velocity of one million miles per hour. 00:00:15
And it's on a collision course with Earth. 00:00:23
But don't worry, this isn't the opening of a new Michael Bay movie. 00:00:28
This is the journey of the polar lights. 00:00:32
The northern and southern lights, also known as the aurora borealis and aurora australis respectively, 00:00:36
occur when high-energy particles from the sun collide with neutral atoms in our atmosphere. 00:00:42
The energy emitted from this crash produces a spectacle of light that mankind has marveled at for centuries. 00:00:46
But the particle's journey isn't just as simple as leaving the sun and arriving at Earth. 00:00:53
Like any cross-country road trip, there's a big detour, and nobody asks for directions. 00:00:56
Let's track this intergalactic voyage by focusing on three main points of their journey. 00:01:02
Leaving the sun, making a pit stop in the Earth's magnetic fields, and arriving at the atmosphere above our heads. 00:01:06
The protons and electrons creating the northern lights depart from the sun's corona. 00:01:13
The corona is the outermost layer of the sun's atmosphere and is one of the hottest regions. 00:01:17
Its intense heat causes the sun's hydrogen and helium atoms to vibrate and shake off protons and electrons, 00:01:22
as if they were stripping off layers on a hot, sunny day. 00:01:28
Impatient and finally behind the wheel, 00:01:31
these freak protons and electrons move too fast to be contained by the sun's gravity 00:01:33
and group together as plasma, an electrically charged gas. 00:01:38
They travel away from the Sun as a constant gale of plasma, known as the solar wind. 00:01:41
However, the Earth prevents the solar wind from traveling straight into the planet by setting up a detour, the magnetosphere. 00:01:46
The magnetosphere is formed by the Earth's magnetic currents and shields our planet from the solar winds by sending out the particles around the Earth. 00:02:01
Their opportunity to continue the journey down to the atmosphere comes when the magnetosphere is overwhelmed by a new wave of travelers. 00:02:08
This event is coronal mass ejection, and it occurs when the Sun shoots out a massive ball of plasma into the solar wind. 00:02:14
When one of these coronal mass ejections collides with Earth, it overpowers the magnetosphere and creates a magnetic storm. 00:02:21
The heavy storm stresses the magnetosphere until it suddenly snaps back, like an overstretched elastic band, flinging some of the detoured particles towards Earth. 00:02:28
The retracting band of the magnetic field guides them down to the aurora ovals, 00:02:37
which are the locations of the northern and southern lights. 00:02:41
After traveling 93 million miles across the galaxy, 00:02:45
the sun's particles finally produce their dazzling light show with the help of some friends. 00:02:48
Twenty to two hundred miles above the surface, 00:02:52
the electrons and protons meet up with oxygen and nitrogen atoms, 00:02:55
and they sure are happy to see each other. 00:02:58
The sun's particles high-five the atoms, 00:03:01
atoms, giving their energy to the Earth's neutral oxygen and nitrogen atoms. 00:03:03
When the atoms in the atmosphere are contacted by the particles, they get excited and emit 00:03:07
photons. 00:03:11
Photons are small bursts of energy in the form of light. 00:03:13
The colors that appear in the sky depend on the wavelength of the atom's photon. 00:03:16
Excited oxygen atoms are responsible for the green and red colors, whereas excited nitrogen 00:03:20
atoms produce blue and deep red hues. 00:03:24
The collection of these interactions is what creates the northern and southern lights. 00:03:27
Polar lights are best seen on clear nights in regions close to the magnetic north and 00:03:35
south poles. 00:03:39
Nighttime is ideal because the aurora is much dimmer than sunlight and cannot be seen in 00:03:40
daytime. 00:03:44
Remember to look up at the sky and read up on the sun's energy patterns, specifically 00:03:45
sunspots and solar flares, as these will be good guides for predicting the auroras. 00:03:50
Subido por:
Alicia M.
Licencia:
Dominio público
Visualizaciones:
58
Fecha:
1 de abril de 2021 - 18:03
Visibilidad:
Público
Centro:
IES LA SENDA
Duración:
04′ 09″
Relación de aspecto:
1.78:1
Resolución:
1920x1080 píxeles
Tamaño:
110.21 MBytes

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