Science topics Magnetism Magnetism Sun spots Sun spots Solar flares Solar flares Corona mass ejections Corona mass ejections

Magnetism Magnetism is the force where objects are attracted or repelled to one another. Magnetism is the force where objects are attracted or repelled to one another. Magnets attract metals containing iron, nickel, and/or cobalt but not most other materials Magnets attract metals containing iron, nickel, and/or cobalt but not most other materials Magnets have two poles where magnetic strength is most powerful. Magnets have two poles where magnetic strength is most powerful.

Magnetism and EMR Keep in mind electricity is just another form of electromagnetic radiation Keep in mind electricity is just another form of electromagnetic radiation When a current (EMR) moves or flows, it creates a magnetic field When a current (EMR) moves or flows, it creates a magnetic field Electric current is the source of magnetism. Electric current is the source of magnetism.

Electric current is charge in motion & anywhere there is an electric current there is a magnetic force field Anywhere there is charge there is an electric force field present Electric current is charge in motion & anywhere there is an electric current there is a magnetic force field Anywhere there is charge there is an electric force field present If an object has no net electric current flowing through it, there will be no magnetic field If an object has no net electric current flowing through it, there will be no magnetic field

Magnetism Bar Magnet with magnetic compasses placed around it. Note how the heads of the compass needles point toward the magnetic south pole and away from the magnetic north pole of the Bar Magnet. (

Magnetic Field line tracing of a bar magnet with a dipole magnetic field using compasses.

Jump Rope Generator Jump Rope Generator worksheet Jump Rope Generator worksheet Jump Rope Generator worksheet Jump Rope Generator worksheet

Sunspots Sunspots are places where strong loops of the Sun’s magnetic fields poke through the Sun’s surface Sunspots are places where strong loops of the Sun’s magnetic fields poke through the Sun’s surface The magnetic fields trap plasma inside and do not allow it outside the loops, causing the area to be cooler than average on the photosphere and makes sunspots appear darker. The magnetic fields trap plasma inside and do not allow it outside the loops, causing the area to be cooler than average on the photosphere and makes sunspots appear darker.

Scientists have found that sunspots are like magnetic poles of a bar magnet. Draw what you predict the magnetic field above the surface of the Sun looks like in the region around the sunspots.

Sunspots and Coronal Loops Above the sunspots, the magnetic field loop also traps hot plasmas = coronal loops. Above the sunspots, the magnetic field loop also traps hot plasmas = coronal loops.

Sunspots Sunspots drift in position relative to one another on the photosphere because of convection beneath the photosphere plus the differential rotation of the Sun. Sunspots drift in position relative to one another on the photosphere because of convection beneath the photosphere plus the differential rotation of the Sun. These motions distort the sunspots’ magnetic fields and cause them to twist up and become more and more complicated in shape. These motions distort the sunspots’ magnetic fields and cause them to twist up and become more and more complicated in shape. The more complicated the magnetic fields shape become, the more energy they store The more complicated the magnetic fields shape become, the more energy they store

Photosphere Visible surface of the Sun about 100 km thick Visible surface of the Sun about 100 km thick Sun rotates on its axis once in about 27 days - equatorial regions rotate faster (about 24 days) than the polar regions (rotate once in <30 days). Sun rotates on its axis once in about 27 days - equatorial regions rotate faster (about 24 days) than the polar regions (rotate once in <30 days). The Sun's rotation axis is tilted by about 7.25 degrees from the axis of the Earth's orbit so we see more of the Sun's north pole in September of each year and more of its south pole in March. The Sun's rotation axis is tilted by about 7.25 degrees from the axis of the Earth's orbit so we see more of the Sun's north pole in September of each year and more of its south pole in March. a.gov/images/sunturn.gif

Solar Flares Sudden, rapid, and intense increases in brightness in relatively small regions in the Sun’s atmosphere Sudden, rapid, and intense increases in brightness in relatively small regions in the Sun’s atmosphere Solar flares occur when magnetic fields in the Sun’s atmosphere rapidly change shape and generate currents of electrically charged plasmas. Solar flares occur when magnetic fields in the Sun’s atmosphere rapidly change shape and generate currents of electrically charged plasmas.

Solar Flares The energy released by flares takes the form of light, heat, and the movement of large amounts of plasma. The energy released by flares takes the form of light, heat, and the movement of large amounts of plasma. Light from across the entire electromagnetic spectrum, from radio waves to gamma rays, can be generated in the biggest flares. Light from across the entire electromagnetic spectrum, from radio waves to gamma rays, can be generated in the biggest flares.

Solar Flares and CME’s Some flares also seem to generate gigantic eruptions of matter that are ejected out into interplanetary space = Coronal Mass Ejections (or CME for short). Some flares also seem to generate gigantic eruptions of matter that are ejected out into interplanetary space = Coronal Mass Ejections (or CME for short).

Solar Flares and EMR Light is also produced in solar flares. Light is also produced in solar flares. Plasma consists of charged particlesPlasma consists of charged particles Plasma moves through magnetic field associated with the sunPlasma moves through magnetic field associated with the sun When charged particles move through a magnetic field they do not follow straight paths but spiral around. This spiraling motion is an acceleration that causes the charged particles to radiate light When charged particles move through a magnetic field they do not follow straight paths but spiral around. This spiraling motion is an acceleration that causes the charged particles to radiate light

Coronal mass ejections Powerful eruptions that can blow up to 10 billion tons of the Sun's atmosphere into interplanetary space. Powerful eruptions that can blow up to 10 billion tons of the Sun's atmosphere into interplanetary space. Traveling away from the Sun at speeds of approximately one million mph (1.6 million kph), CMEs can create major disturbances in the interplanetary medium and trigger severe magnetic storms when they collide with Earth's magnetosphere. Traveling away from the Sun at speeds of approximately one million mph (1.6 million kph), CMEs can create major disturbances in the interplanetary medium and trigger severe magnetic storms when they collide with Earth's magnetosphere.

CME’s Large geomagnetic storms directed towards Earth can damage and even destroy satellites, are extremely hazardous to Astronauts when outside of the protection of the Space Shuttle performing Extra Vehicular Activities (EVAs), and they have been known to cause electrical power outages. Large geomagnetic storms directed towards Earth can damage and even destroy satellites, are extremely hazardous to Astronauts when outside of the protection of the Space Shuttle performing Extra Vehicular Activities (EVAs), and they have been known to cause electrical power outages.

Space Weather Solar storm from the Sun travels through space and impacts the Earth’s magnetosphere. Solar storm from the Sun travels through space and impacts the Earth’s magnetosphere. Studying space weather is important to our national economy because solar storms can affect the advanced technology we have become so dependent upon Studying space weather is important to our national economy because solar storms can affect the advanced technology we have become so dependent upon

Space Weather Energy and radiation from solar flares and coronal mass ejections can: Energy and radiation from solar flares and coronal mass ejections can: Harm astronauts in spaceHarm astronauts in space Damage sensitive electronics on orbiting spacecraft…Damage sensitive electronics on orbiting spacecraft… Cause colorful auroras, often seen in the higher latitudes…Cause colorful auroras, often seen in the higher latitudes… Create blackouts on Earth when they cause surges in power grids.Create blackouts on Earth when they cause surges in power grids.

Solar Wind The solar wind speed is not uniform The solar wind speed is not uniform Always directed away from the Sun Always directed away from the Sun Solar wind speed is 800 km/s over coronal holes and low (300 km/s) over streamers. Solar wind speed is 800 km/s over coronal holes and low (300 km/s) over streamers. High and low speed streams interact with each other and pass by the Earth as the Sun rotates and can produce storms in the Earth's magnetosphere. High and low speed streams interact with each other and pass by the Earth as the Sun rotates and can produce storms in the Earth's magnetosphere.

Solar wind The solar wind consists of particles, ionized atoms from the solar corona, and fields, in particular magnetic fields. The solar wind consists of particles, ionized atoms from the solar corona, and fields, in particular magnetic fields. As the Sun rotates the magnetic field transported by the solar wind gets wrapped into a spiral As the Sun rotates the magnetic field transported by the solar wind gets wrapped into a spiral Variations in the Sun's magnetic field are carried outward by the solar wind Variations in the Sun's magnetic field are carried outward by the solar wind

Solar wind Solar wind streams off of the Sun in all directions at speeds of about 400 km/s (about 1 million miles per hour). Solar wind streams off of the Sun in all directions at speeds of about 400 km/s (about 1 million miles per hour). Source of the solar wind is the Sun's corona where the temperature is so high that the Sun's gravity cannot hold on to it. Source of the solar wind is the Sun's corona where the temperature is so high that the Sun's gravity cannot hold on to it. We do not understand the details about how and where the coronal gases are accelerated to these high velocities. We do not understand the details about how and where the coronal gases are accelerated to these high velocities.

Magnetosphere Solar wind and its magnet field, is strong enough to interact with the planets and their magnetic fields to shape magnetospheres Solar wind and its magnet field, is strong enough to interact with the planets and their magnetic fields to shape magnetospheres A magnetosphere is the region surrounding a planet where the planet's magnetic field dominates A magnetosphere is the region surrounding a planet where the planet's magnetic field dominates

Magnetosphere protects life on Earth Because ions in the solar plasma (wind)are charged Because ions in the solar plasma (wind)are charged They interact with these magnetic fieldsThey interact with these magnetic fields Solar wind particles are swept around planetary magnetospheres.Solar wind particles are swept around planetary magnetospheres. Life on Earth has developed under the protection of this magnetosphere.Life on Earth has developed under the protection of this magnetosphere.

Shape of Earth’s Magnetosphere Solar wind compresses its sunward side to a distance of 6 to 10 times the radius of the Earth. Solar wind compresses its sunward side to a distance of 6 to 10 times the radius of the Earth. A shock wave is created sunward of Earth like a sonic boom – called the bow shock. A shock wave is created sunward of Earth like a sonic boom – called the bow shock. Most of the solar wind particles are heated and slowed at the bow shock and detour around the Earth. Most of the solar wind particles are heated and slowed at the bow shock and detour around the Earth.

Solar wind drags out the night-side magnetosphere to possibly 1000 times Earth's radius (exact length unknow) Solar wind drags out the night-side magnetosphere to possibly 1000 times Earth's radius (exact length unknow) This extension of the magnetosphere is known as the magnetotail. Many other planets in our solar system have magnetospheres of similar, solar wind-influenced shapes. This extension of the magnetosphere is known as the magnetotail. Many other planets in our solar system have magnetospheres of similar, solar wind-influenced shapes.

Earth’s Magnetosphere Magnetosphere is dynamic and fluctuates with time Magnetosphere is dynamic and fluctuates with time

Magnetism in space In space there is no magnetic iron, yet magnetism is widespread. In space there is no magnetic iron, yet magnetism is widespread. Sunspots consist of glowing hot gas, yet they are all intensely magnetic. Sunspots consist of glowing hot gas, yet they are all intensely magnetic. The Earth's own magnetic powers arise deep in its interior, and temperatures there are too high for iron magnets The Earth's own magnetic powers arise deep in its interior, and temperatures there are too high for iron magnets It is all related to electricity It is all related to electricity

Remember: anywhere there is an electric current there is a magnetic force field and anywhere there is charge there is an electric force field present Remember: anywhere there is an electric current there is a magnetic force field and anywhere there is charge there is an electric force field present So movement of sunspots with plasma and CME’s will pass through magnetic fields and produce electric fields So movement of sunspots with plasma and CME’s will pass through magnetic fields and produce electric fields

On the left, a model of the magnetic field (spiral lines) of the Sun (in the middle) is shown as one looks down on the Sun’s axis of rotation. This magnetic field is known as the interplanetary magnetic field (IMF). The orbits of Mercury, Venus, and Earth are shown as circles. The spiral of the IMF shown here is due to the fact that the IMF is attached to the rotating Sun, but we draw it from a non-rotating perspective from above.