The Sun interacts with the Earth throughThe Sun interacts with the Earth throughElectromagnetic RadiationElectromagnetic Radiation
andandThe The Solar Solar WindWind
Image courtesy of National Aeronautics and Space Administration (NASA)
Electromagnetic RadiationElectromagnetic Radiation
Travels at the speed of light, 300,000 km/s (186,000 mi/s)
Takes approximately 8 minutes to reach the Earth
Image courtesy of Occupational Safety & Health Administration (OSHA)
The Solar WindThe Solar Wind
Consists of charged Consists of charged particles (protons and particles (protons and electrons)electrons)
Takes several days to Takes several days to reach the earthreach the earth
Average density is 5Average density is 5--10 particles per cubic 10 particles per cubic centimetercentimeter
Courtesy of SOHO/EIT consortium. SOHO is a project of international cooperation between ESA and NASA
The CoreThe Core
It’s HOT!!!! 15 It’s HOT!!!! 15 Million degrees Million degrees KelvinKelvin
It’s DENSE!!!! 10 It’s DENSE!!!! 10 times more dense times more dense than leadthan lead
And……Image courtesy of Tungsten Heavy Powder, Inc.
FusionFusion
At that temperature At that temperature and density, nuclear and density, nuclear fusion occursfusion occurs
Fusion is the source Fusion is the source of the sun’s of the sun’s electromagnetic electromagnetic radiationradiation
Image courtesy of the Lawrence Berkeley National Laboratory
Did You Know?Did You Know?
The sun converts The sun converts 5 million tons 5 million tons of matter into of matter into energy every energy every second.second.
RadiativeRadiative ZoneZoneEnergy is Energy is transported from transported from the core through the core through radiationradiation
Energy is Energy is constantly constantly absorbed and reabsorbed and re--emitted by atomsemitted by atoms
Courtesy of SOHO/EIT consortium. SOHO is a project of international cooperation between ESA and NASA
It’s a LONG RoadIt’s a LONG Road
It takes thousands to It takes thousands to millions of years for millions of years for the energy released by the energy released by the fusion process to the fusion process to reach the sun’s reach the sun’s convective zoneconvective zone
Image credit Yohkoh Public Outreach Project
Convective ZoneConvective Zone
Energy transfer is Energy transfer is similar to motion of similar to motion of boiling water in a potboiling water in a pot
Hot interior gases Hot interior gases move outward as move outward as cooler gases sinkcooler gases sink Image courtesy of the Alder Planetarium
Layer of the Sun we see
Visible sunspots
Exhibits granulation
PHOTOSPHERE
Image courtesy of Space Science News
Solar GranulesSolar Granules
Visible proof of Visible proof of convection zoneconvection zone
Masses of hot gas that Masses of hot gas that rise and fall rise and fall
Each granule is about Each granule is about the size of an earth the size of an earth continent continent
Image courtesy of National Aeronautics and Space Administration (NASA)
Sun’s outer atmosphere
Temperature rises to millions of degrees K
Extends millions of kilometers into space
CoronaCorona
Image courtesy of National Aeronautics and Space Administration (NASA)
Did You Know?Did You Know?
The Sun’s corona The Sun’s corona or atmosphere is or atmosphere is hundreds of times hundreds of times hotter than its hotter than its surfacesurface
Image courtesy of National Aeronautics and Space Administration (NASA)
Solar EventsSolar Events
Sun spotsSun spots
Solar flaresSolar flares
Coronal mass Coronal mass ejections (CME’s)ejections (CME’s)
Courtesy of SOHO/EIT consortium. SOHO is a project of international cooperation between ESA and NASA
Sun SpotsSun Spots
Cool areas of the Cool areas of the photospherephotosphere
Number varies in Number varies in approximate 11 year approximate 11 year solar cyclesolar cycle
Produced by local Produced by local solar magnetic fieldssolar magnetic fields Size of Earth
Courtesy of SOHO/MDI consortium. SOHO is a project of international cooperation between ESA and NASA
Solar FlaresSolar Flares
Most occur in and Most occur in and around sun spotsaround sun spots
Frequency follows Frequency follows solar cyclesolar cycle
Source of dangerous Source of dangerous levels of radiationlevels of radiation
solar flare
Courtesy of SOHO/EIT consortium. SOHO is a project of international cooperation between ESA and NASA
Coronal Mass Ejection (CME)Coronal Mass Ejection (CME)
Eruption of large Eruption of large bubble of solar bubble of solar materialmaterial
Creates the most Creates the most adverse effect on adverse effect on Earth’s Earth’s magnetospheremagnetosphere
Courtesy of SOHO/LASCO consortium. SOHO is a project of international cooperation between ESA and NASA
Two main components of the earth system affected by solar activity are:
The earth’s ionosphere (upper atmosphere)
The earth’s magnetic field, called the magnetosphere
The Structure of the Earth
Image credit – The Canadian Space Agency http://www.space.gc.ca/
Image courtesy of National Aeronautics and Space Administration (NASA)
The IonosphereThe IonosphereFar above the area in Far above the area in which we livewhich we live
Layer of the earth's Layer of the earth's atmosphere that is atmosphere that is ionized by solar radiation ionized by solar radiation
Plays a significant role in Plays a significant role in radio, television, and radio, television, and satellite communicationssatellite communications
Courtesy of Windows to the Universe, http://www.windows.ucar.edu
The MagnetosphereThe Magnetosphere
Area of space around the Area of space around the Earth that is controlled by Earth that is controlled by the Earth's magnetic fieldthe Earth's magnetic field
Shape is the direct result Shape is the direct result of being blasted by solar of being blasted by solar wind wind
Protects us from most of Protects us from most of the harmful effects of the harmful effects of space weatherspace weather
Image courtesy of National Aeronautics and Space Administration (NASA)
Space WeatherSpace Weather
The condition of the The condition of the space environment space environment influenced by the suninfluenced by the sun
Earth consequences Earth consequences can be beautiful but can be beautiful but disruptive disruptive
Image courtesy of Stanford Solar Center
Aurora BorealisAurora BorealisAlso known as the Also known as the northern lightsnorthern lights
Solar wind excites Solar wind excites gases in the gases in the ionosphereionosphere
Most common sign Most common sign of space weather of space weather activityactivity Image courtesy of National Aeronautics and Space
Administration (NASA)
Did You Know?Did You Know?During a major During a major solar storm, solar storm, auroras can be auroras can be seen as far south seen as far south as Florida, Texas, as Florida, Texas, and even Mexicoand even Mexico..
Image courtesy of National Aeronautics and Space Administration (NASA)