4. Look familiar?
This is the International Space Station and the NASA space shuttle (left) in
silhouette as photographed by an amateur using a telescope with a solar filter.
5. The sun calmly rises each morning
in the east, just like clockwork.
Credit: the SolarMax IMAX film
6. The Sun, with all the planets revolving
around it, and depending on it, . . .
Credit: Chris Linder
7. can still ripen a bunch of grapes as though . . .
Credit: Chris Linder
8. . . . it had nothing else in the universe to do.
. . . Galileo
Credit: Chris Linder
9. Amateurs capture the Sun
Amateur astronomers can
now use $500 telescopes
and cameras to take
photographs that show
features of activity
12. Our Solar System The Sun is the center of our
solar system. All the planets and
comets, everything in the solar
system revolves around it.
13. The Milky Way galaxy
• Our galaxy, the
Milky Way, is just
one of perhaps
billions of galaxies
in the universe
• The closest star to
Earth is about four
light years away
• There are more stars
than grains of sand
on Earth
Our Milky Way galaxy seen at night
16. The Dynamic Sun
The Sun, like all
stars, is a
dynamic star,
always active,
always changing.
The more we
learn about it, the
more we learn
about all stars.
17. Where the action is
• Nuclear fusion occurs in
the Sun’s core
• Hydrogen atoms combine
to form helium and
release huge amounts of
energy, radiation and
light
• It takes over 10,000 years
for the light to get to the
Sun’s surface
The Sun vibrates from material moving inside of it and we have translated those
vibrations into sound. Click HERE and turn up your volume to hear it.
18. Solar influence
We live in the atmosphere of the Sun, basking in its light
and warmth, protected by our magnetic shield, the
magnetosphere (green lines in the video clip). We are
also struck constantly by the flow of its solar wind.
19. The Sun is also the source of radiation and storms that we call
SPACE WEATHER!
Credit: the SolarMax IMAX film
20. First recorded sunspots
Galileo in 1610, using one of the first (just invented) telescopes, was the
first person to observe and record the path of sunspots across the Sun for
several weeks.
21. Sunspots from down under
• Sunspots are magnetic
structures that emerge
from beneath the surface
• The white lines represent
magnetic field lines
• When the lines tangle and
break apart, they are the
creators of solar storms
22. A sunspot is a kind of whirlpool controlled by intense magnetic forces
where hot gases from inside the Sun are blocked from reaching the surface.
Therefore they are cooler than the rest of the Sun and appear darker.
Sunspots
The Sun as
seen here
rotates about
every 27 days.
23. The average sunspot is about the size of Earth, though the
largest can be 20 times the size of Earth.
24. Zooming in for a closer look
From far away
sunspots appear like dark
blobs on the Sun, but up
close, they reveal
incredible complexity.
In the most close-up
view, each little cell-like
gray area you see is
about the size of Texas.
Credit: Swedish Solar Telescope
25. This close-up video shows how sunspots and
the Sun’s surface can change in just half an hour.
26. Solar Cycles
Since about 1750, people have kept written records of sunspots, so that we
know of the solar cycle, which is the rise and fall of sunspot numbers (and
solar activity) about every 11 years. This is due to the Sun’s changing
magnetic structure.
27. Next solar cycle
• Was near its peak
level or “solar
maximum” at late
2000 or early
2001.
• Scientists predict
that the next solar
maximum period
(around 2013)
will be milder
than usual.
• Dotted lines show
range of
prediction; solid
curve is the
average; jagged
lines are monthly
counts
28. Solar Rotation
• The Sun rotates every 27 days or so. This causes magnetic field
lines to become twisted and stretched to the breaking point.
These eventually break and reconnect, creating heat, intense
active regions, and solar blasts of charged particles.
29. Different Solar Rotation
It must be noted that since the Sun is made of a gaseous plasma and is not a
solid body, it does not rotate at the same speed at all places. Specifically, near
the poles the surface rotates in around 35 days, but near its equator the Sun
rotates about every 25 days. This is called differential rotation. This process
leads to stretching and stressing of the Sun’s magnetic field, which does cause
solar storms.
30. Underlying magnetism
Sunspots are magnetic
features of the Sun.
Magnetic field lines get
tangled up in sunspots,
block energy, and make
the area cooler and
darker. When a surface
image of sunspots is
compared to a black and
white image of the
Sun’s magnetic field
strength (see video clip),
the features line up
almost exactly.
31. It’s all in the magnetism!
The Sun is strongly affected by magnetic forces. Solar storms carry
magnetic fields with them into space. These can interact with Earth’s
magnetic field and often cause aurora to appear in the night sky.
32. Storms at their source
When the magnetic forces above sunspots become tangled and break apart, violent
storms can burst from the Sun. This is the main source of our strongest space
weather events, either coronal mass ejections or solar flares. The white specks
near the end of the clips are protons from the blast hitting the spacecraft’s imager.
33. Coronal mass ejections (CMEs)
• CMEs are large solar
storms that can blast out a
cloud of billions of tons of
particles at over two
million Km per hour.
Smaller ones can occur
almost any day.
• The clouds reach Earth’s
orbit in 1 to 3 days but
only a few of them
actually head our way.
34. Solar flares
• Flares are quick, intense
but smaller explosions
than CMEs
• They appear as bright
flashes sometimes
followed by a burst of
high energy particles
that can travel at half the
speed of light. Large
flares can occur several
times a year when the
Sun is near its peak
activity.
(Green tint has been added)
35. Loops after a storm
This close-up video
shows a whole parade
of bright magnetic loop
forming as the magnetic
field reorganizes after a
powerful flare/CME
combination.
36. Magnetic struggles
In UV light, the
area above a
sunspot is seen
from the side as
wildly violent as
magnetic forces
fight for control.
The video shows
about 2 days of
activity.
37. Stormy
weather
In October 2003 the Sun produced a record series of strong storms. This
UV light video (green color added) shows many bursts of solar storms.
The largest are called coronal mass ejections. These occur almost daily,
but the larger ones occur only a few times a year. The brightest flashes are
solar flares. Sometimes these both occur together.
38. CME in a Coronagraph
In this stop-motion clip with the Sun blocked (red disk) to reveal the
faint corona, we see a coronal mass ejection (CME) bursting into
space over a few hours. This instrument that produced this kind of
image is a coronagraph. The white circle represents the covered Sun.
39. CME clouds heading into space
With the Sun blocked out, clouds of material blasting out into space at about 2
million MPH can be seen. This clip shows 5 days of powerful solar activity.
40. Earth’s magnetic shield
The Earth has a magnetic field with north and south poles. The
Earth's magnetic field reaches 36,000 miles (57,000 km) into space.
Earth is surrounded by a
region called the
magnetosphere. This
prevents most of the
particles from the Sun,
carried in solar wind and
storms, from hitting the
Earth. Some particles can
enter the magnetosphere.
Particles that enter from
the tail end travel toward
the Earth and create the
aurora light shows.
41. A solar storm heads our way
A CME hits Earth’s magnetic shield and flows to the back side,
where magnetic energy builds up. Earth’s magnetic field then
snaps back, sending material back into our atmosphere near the
poles along the magnetic field lines.
42. Polar auroral ovals
Actual aurora footage shown on a model Earth
If a storm cloud of charged particles is headed towards Earth, we will experience
space weather first-hand in one to three days. Our magnetic field
(magnetosphere) shields us, but energized particles can spiral down our
magnetic field lines and glow as oval aurora near the Earth’s Poles.
44. Aurora
Aurora, often called the Northern and Southern Lights, are visible signs of the
Sun’s electrical connection to the Earth. The video clip shows aurora in real
time as it changes -- not speeded up. Video credit: Aurora Experience
45. Space weather upsets
There are less pleasant space weather effects. Energy pumped into our
atmosphere upsets modern technology. Radio signals and
communications become disrupted. Satellites orbiting around Earth
can suffer damage. On the ground, magnetic field changes can damage
electrical equipment on Earth.
46. Astronaut safety
Astronauts can get high doses of radiation from solar storms and cosmic
radiation when out in space. For humans to travel to the Moon and
Mars, better storm forecasting and shielding will be needed.
47. Global Warming?
It is important to understand the long-term changes in the Sun and their
potential effects on
climate. These
changes include
general activity level
(see chart), UV
radiation, and total
energy output. Solar
general activity may
influence cloud
formation which can,
in turn, trap heat in
Earth’s atmosphere.
Man-made factors
seem to play an
important role in
global warming.
48. The Sun’s role
Is the Sun's variability tied to Earth's climate? Some scientists cite a
correlation with droughts, small ice ages, and large-scale weather
patterns on Earth. Many scientists are researching this topic today.
The latest research suggests that a small variability of the Sun can
drive large-scale changes in weather. The small increase in solar
radiation over the past 200 years may account for a part of our
global warming. The general consensus is that man-made causes
are the major driving force in global warming.
During the “Little Ice Age” in the 17th
Century, Holland’s canals often froze in
winters, a very rare event that does not
occur anymore. This coincided with a
period of very few sunspots and much
lower than normal solar activity.
49. Solar exploration in space
NASA is actively
involved in
exploration of the
Sun and space
weather. SOHO (the
Solar and
Heliospheric
Observatory) has
been the main solar
watchdog for over 11
years. Another,
TRACE, is learning
more about solar
storms. And there are
others too!
50. SOHO
(Solar and Heliospheric Observatory)
• a joint mission of NASA and
the European Space Agency
(ESA) studying the Sun since
1996
• 12 instruments to study the
Sun’s interior, atmosphere,
and solar wind all day every
day
• a major tool for monitoring
space weather
• weighs 2 tons; its solar panels
span 25 feet
• SOHO is 1 million miles (1.6
million Km) towards the Sun
51. SOHO science
• Discover the source
of high speed solar
wind
• Learn more about the
structure inside the
Sun
• Find the causes of
solar storms
• Monitor space
weather for the world
52. TRACE
• Studies the Sun and
solar events at a much
smaller scale than
SOHO
• Launched in 1999
• Works closely with
SOHO
53. Some TRACE Images
• Close-ups of flares
and loops
Video credit: SolarMax IMAX film
54. A recent solar mission, STEREO , launched in Oct. 2006, is unique.
A pair of nearly identical NASA spacecraft are studying the Sun from
positions ahead of and trailing Earth. They are collecting data and providing
3-D views of solar storms for the first time ever.
55. First image of the Sun from STEREO
Dr. Lika Guhathakurta,
STEREO Program Scientist,
NASA
This looks a lot like a SOHO image, doesn’t it? The
difference is in the level of details that the STEREO imager
can capture -- two times as much!
56. Detailed STEREO images
• New
coronagraph
and
ultraviolet
images
provide
sharper
details than
ever before
(2007)
Solar loops arcing above active regions in extreme UV light
57. STEREO sees erupting prominence
• With images taken
every 10 minutes
in four
wavelengths of
light, STEREO
captures more
events like this
than SOHO can.
58. 3-D Sun
Scientists have waited for years to view the first ever 3-D views of the Sun from
STEREO and at a level of detail never seen before! (You need 3D glasses to
see this in 3D.)
This image is a composite made from three wavelengths of light
captured by each of the two STEREO spacecraft
59. More Sun-Earth missions
Missions from NASA and other U.S. and TIMED
foreign agencies exist or are planned for
launch to study and monitor space
weather. These will create a way to
THEMIS
observe the Sun-Earth connections as an
interactive system. Hinode
Solar Dynamics
Observatory
Magnetospheric
Multi-Scale
Solar Sentinels
60. Solar Dynamics Observatory (SDO)
• A “supercharged” SOHO on steroids
• To launch in 2009
• With images 4 times more detailed and 10 times more
often than SOHO
61. Monitoring the Sun
Solar activity is being monitored around the clock. If there
is a possible impact predicted from a solar storm, alerts
are sent out from NOAA’s Space Environment Center to
the rest of the world.
62. NASA will continue to explore the Sun-Earth connection over the next solar cycle
and beyond. The more dependent we become on technology, the more we need to
understand space weather and how it can affect our lives.
Video clip: SolarMax, Chicago Museum of Science & Industry
