News, Updates, and Resources for Our Very Own Star
- January 2011. JHelioviewer software. JHelioviewer
is open-source software for viewing the Sun from a variety of sources,
created by a team from the European Space Agency.
- March 2010. Online Resources:
- 2005 March 10. Hands-On
Exercise: Finding Solar North. [NASA Sun-Earth Day
activity] Context: A compass uses the
Earth's magnetic field to find north and therefore points
toward magnetic north, which is not in the same place
as geographic or due north. A shadow plot can help you
obtain a feel for how the Sun's path changes across the
sky from day to day. During the course of only one day
a shadow plot can help you determine which direction
is due north at the location where the shadow plot is
made.
Materials: pointed stick (example: skewer stick),
5 to 15 cm tall; piece of cardboard, at least 30 x 50
cm; cardboard box at 5 to 10 cm tall (example: lid to
copier paper box works well); protractor and ruler; markers;
glue; large paper, at least 30 x 50 cm; tape.
Set Up: Have students work in groups of 3 or 4.
Activity: Tape the larger piece of paper to the
piece of cardboard. Mark the center of the paper with
a dot using the marker. Through this dot draw two lines
that are perpendicular to each other: one from top to
bottom across the paper, and the other from left to right
across the paper. Insert the pointed end of the stick
through the center dot and into the cardboard. Use tape
to secure the stick on the bottom of the box. Using the
protractor, verify that the stick is straight. This is
very important.
On a clear day, find a large open area outside
(a parking lot area works best). Place the longest edge
of paper along the edge of the parking lot or along a
painted mark on the parking lot. (Remember this orientation
of the box and the way your orientated your paper or
tape the box to the ground.) Starting as early in the
morning as possible, trace the shadow of the stick every
half hour until the end of the day, labeling the time
after each tracing. Find two shadows that are the same
length. They should be on different sides of the paper
(either one towards the top and one towards the bottom,
or one towards the left and one towards the right). Trace
the angle of these two lines, then bisect the angle.
On the original sun plot draw the bisector angle. When
the plot is in its established position on the parking
lot, this line points towards true solar north. Check
the newspaper to find the times for sunrise and sunset;
determine the midpoint between these two times. Check
the midpoint on your plot to determine your accuracy.
This activity is part of the complete activity
designed by NASA Connect for 2005 Sun-Earth Day.
- 2008 September 23. NASA
RELEASE: 08-241. Ulysses Reveals Global Solar Wind Plasma
Output At 50-Year Low. Excerpt: WASHINGTON
-- Data from the Ulysses spacecraft, a joint NASA-European
Space Agency mission, show the sun has reduced its output
of solar wind to the lowest levels since accurate readings
became available. The sun's current state could reduce
the natural shielding that envelops our solar system.
"The sun's million mile-per-hour solar wind inflates
a protective bubble, or heliosphere, around the solar
system...." said Dave McComas, Ulysses' solar wind
instrument principal investigator.... "Ulysses data
indicate the solar wind's global pressure is the lowest
we have seen since the beginning of the space age."
...Galactic cosmic rays carry with them radiation
from other parts of our galaxy," said Ed Smith,
NASA's Ulysses project scientist at the Jet Propulsion
Laboratory in Pasadena, Calif. "With the solar wind
at an all-time low, there is an excellent chance the
heliosphere will diminish in size and strength. If that
occurs, more galactic cosmic rays will make it into the
inner part of our solar system."
Galactic cosmic rays are of great interest to NASA.
Cosmic rays are linked to engineering decisions for unmanned
interplanetary spacecraft and exposure limits for astronauts
traveling beyond low-Earth orbit....
- 2008 January 25. NASA
PODCAST: WHERE DID THE SUN'S MAGNETIC FIELD COME FROM? The
sun contains the most powerful magnetic field of any
body in our solar system. In this 12 minute podcast,
NASA scientist, Sten Odenwald, discusses a major question
in solar physics: "Where does the Sun's magnetic
field come from?"
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