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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