SOLAR PHYSICS Advanced Space Academy U.S. Space & Rocket Center.
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Transcript of SOLAR PHYSICS Advanced Space Academy U.S. Space & Rocket Center.
SOLAR PHYSICS
Advanced Space Academy
U.S. Space & Rocket Center
SOLAR PHYSICS
Why the Sun?The Ozone HoleSolar StructureSolar FeaturesSolar Missions
Why The Sun?
Clues to our origins
Curiosity
Energy Source
Predict communication
problems
Avoid endangering astronauts and spacecraft
http://science.nasa.gov/headlines/y2001/ast17sep_1.htm
The Ozone Hole
16,000,000 square miles (26,000,000 square km) in size
Mainly located over Antarctica; however, its boundaries can extend upward uncovering portions of Australia, South America, and South Africa
Exacerbated by CFC’s
Solar Structure
Early Life– Gas & dust
– Shock waves & gravity
– Contraction increased pressure and temperature
– Fusion at 15 million degrees F (8.3 million degrees C)
– Electromagnetic radiation
http://www.windows.ucar.edu/tour/link=/sun/statistics.html&edu=high
Sun Facts
Mass - 1 billion trillion trillion tons330,000 times the Earth’s massDiameter - 864,000 miles (1,390,000 km)75% Hydrogen and 25% Helium by mass93,000,000 miles (150,000,000 km) from
EarthThe sun is an average G2 star
(classification on next slide)
Sun Facts: Classification G2
http://windows.arc.nasa.gov/tour/link=/sun/sun.html&edu=high
Solar Structure
4 layers:– Core
– Photosphere
– Chromosphere
– Corona
Radiation Travel Times:– millions of years from core
to chromosphere
– 8 minutes to Earth
Striated rotation
MidlifeOur Sun contains 99.9% of the
matter in our solar system
http://windows.arc.nasa.gov/tour/link=/sun/activity/solar_cycle.html&edu=high
The Solar Cycle
The Sun goes through a cycle every 11 years
Solar MinimumSolar MaximumThe 11 year sunspot cycle is actually
related to a 22 year cycle for the reversal of the Sun's magnetic field.
Our Sun is an Active Star
http://science.msfc.nasa.gov/ssl/pad/solar/interior.htm
Solar Midlife - Core
Temperature – 27,000,000°F (15,000,000 °C)
Pressure - 250 billion atmospheres
The Radiative ZoneThe Interface LayerThe Convection Zone
Solar Midlife - Core
MAGNETISM – the key to understanding the Sun
The magnetic field is produced in the Sun by the flow of electrically charged ions and electrons most likely in the interface layer
http://science.msfc.nasa.gov/ssl/pad/solar/surface.htm
Solar Midlife - Photosphere
Temperature - 10,500°F (5,800ºC)
The sun’s lower atmosphere
62 miles (100 km) thick It gives off most of its
energy as visible light and heat
Sunspots originate on this layer
http://www.space.com/scienceastronomy/top10_2002_021224-8.html
Photospheric Features
SUNSPOTS appear as dark spots on
the sun They are really several
spots clustered together They originate at the poles They are magnetic Sunspots are “cool”
regions - 6,800°F (3,800ºC) compared to their surroundings
Photospheric Features
SUNSPOTS– Observing sunspots
“moving” across the Sun was how scientists figured out that the Sun actually rotated
http://science.msfc.nasa.gov/ssl/pad/solar/feature1.htm
Photospheric Features
FACULAE– Bright areas seen near
the edge of the solar disk
– These are magnetic areas but the magnetic field is in smaller bundles than in sunspots
http://science.msfc.nasa.gov/ssl/pad/solar/feature1.htm
Photospheric Features
GRANULES– Small cellular features that
cover the entire Sun except for those areas covered by sunspots
– Individual granules last for only about 20 minutes
– The flow within the granules can reach supersonic speeds and produce sonic “booms” that generate waves on the Sun’s surface
http://science.msfc.nasa.gov/ssl/pad/solar/feature1.htm
Photospheric Features
SUPERGRANULES
– Much larger versions of granules
– The fluid flows observed in supergranules carry magnetic field bundles to the edges of the cells where they produce the chromospheric network
Solar Midlife - Chromosphere
Faint and red - seen only briefly during an eclipse
Temperature rises from 10,800°F (6,000ºC) to 36,000°F (20,000ºC)
http://science.msfc.nasa.gov/ssl/pad/solar/feature2.htm#Network
Chromospheric Features
CHROMOSPHERIC NETWORK
– Web-like pattern
– Outlines the supergranule cells seen on the photosphere
http://science.msfc.nasa.gov/ssl/pad/solar/feature2.htm#Network
Chromospheric Features
FILAMENTS – dense, somewhat
cooler, clouds of material suspended above the chromosphere by loops of magnetic field
PLAGE – bright patches above
sunspots
http://science.msfc.nasa.gov/ssl/pad/solar/feature2.htm#Network
Chromospheric Features
PROMINENCES– dense clouds of material
suspended above the surface of the Sun by loops of magnetic field
http://science.msfc.nasa.gov/ssl/pad/solar/feature2.htm#Network
Chromospheric Features
SPICULES– Small jet-like
eruptions seen throughout the chromospheric network
Chromospheric Features
SOLAR FLARES – can release as much energy as a billion megatons of TNT
http://science.msfc.nasa.gov/ssl/pad/solar/t_region.htm
Transition Region
A very thin, irregular layer of the Sun that separates the chromosphere from the corona
Temperature changes very rapidly in this region and causes hydrogen to become stripped of its electrons.
The light emitted by the transition region is dominated by ions illustrated in the pictures
http://science.msfc.nasa.gov/ssl/pad/solar/corona.htm
Solar Midlife - Corona
The Sun’s outermost atmosphere
Temperature is 1,800,000°F (1,000,000°C)
The Solar Corona – The White-Light Corona
– The Emission Line Corona
– The X-Ray Corona
http://science.msfc.nasa.gov/ssl/pad/solar/corona.htm
Solar Midlife - Corona
EMISSION LINE CORONA
Since hydrogen atoms have been ionized only the heavier trace elements like iron and calcium are able to retain a few of their electrons in this intense heat
It is emission from these elements that produce the color associated with the emission line corona
http://science.msfc.nasa.gov/ssl/pad/solar/corona.htm
Solar Midlife - Corona
X-RAY CORONA The corona shines
brightly in x-rays because of its high temperature while other layers of the Sun do not emit x-rays
This allows us to view the corona across the disk of the Sun when we use an X-Ray telescope
http://science.msfc.nasa.gov/ssl/pad/solar/feature3.htm
Coronal Features
HELMET STREAMERS
Large cap-like coronal structures with long pointed peaks that usually overlie sunspots and active regions formed by a network of magnetic loops
http://science.msfc.nasa.gov/ssl/pad/solar/feature3.htm
Coronal Features
POLAR PLUMESLong thin streamers
that project outward from the Sun’s north and south poles
They are associated with the “open” magnetic field lines at the Sun’s poles
http://science.msfc.nasa.gov/ssl/pad/solar/feature3.htm
Coronal Features
CORONAL LOOPS Found around sunspots
and in active regions Associated with the
closed magnetic field lines that connect magnetic regions on the solar surface
Some loops appear after solar flares
http://science.msfc.nasa.gov/ssl/pad/solar/feature3.htm
Coronal Features
CORONAL HOLES Regions where the corona
is dark Associated with “open”
magnetic field lines and are often found at the poles
The solar wind originates in coronal holes
http://www.gsfc.nasa.gov/topstory/20021030solar.html
Coronal Features
CORONAL MASS EJECTIONS (CMEs)
huge bubbles of gas threaded with magnetic field lines that are ejected from the Sun over the course of several hours.
CMEs can disrupt the flow of the solar wind
CMEs are often associated with solar flares and prominence eruptions but they can also occur in the absence of either of these processes.
http://antwrp.gsfc.nasa.gov/apod/ap020101.html
The Solar Wind
The solar wind streams off of the Sun in all directions at speeds of about 1 million miles per hour
The source of the solar wind is the Sun's hot Corona
The temperature of the corona is so high that the Sun's gravity cannot hold on to it
http://sohowww.nascom.nasa.gov/
The Solar and Heliospheric Observatory (SOHO)
The SOHO spacecraft is a joint effort between NASA and ESA
It was launched on December 2, 1995
SOHO will take measurements of the solar interior, the solar atmosphere, and the solar wind
http://antwrp.gsfc.nasa.gov/apod/ap021221.html
SOHO Images
Composite picture of 3 images taken by the EIT instrument on board SOHO
Each individual image shows a different temperature in the upper solar atmosphere and was assigned a specific color
Red at 2 million degrees F Green at 1.5 million degrees F
Blue at 1 million degrees F
http://vestige.lmsal.com/TRACE/
Transition Region and Coronal Explorer (TRACE)
TRACE will explore the magnetic field in the solar atmosphere
TRACE will work in conjunction with SOHO for part of its mission
It was launched by a Pegasus rocket in April 1998
http://vestige.lmsal.com/TRACE/Science/ScientificResults/trace_cdrom/html/trace_images.html
TRACE Images
Solar flare observed on May 19,1998
A solar flare is a rapid release of energy from a localized region on the Sun in the form of electromagnetic radiation, energetic particles, and mass motions
http://genesismission.jpl.nasa.gov/
GENESIS – Search for Origins
What is the Sun made of? Launched August 8, 2001 Genesis will collect solar
wind samples for 2 years Libration points 22.3 ft (6.8m) solar panel
length 1402 lbs (636 kg) at
launch
http://www.astronomynotes.com/evolutn/chindex.htm
Solar Structure
•The End•Hydrogen depletion
•Red giant
•Fusion stops, outward pressure decreases
•Collapse
•Planetary Nebula
•White Dwarf