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Sun-Earth Day Presents: Ancient Observatories, Timeless Knowledge

Technology Through Time: Issue #9, Mount Wilson

Over 200 years after Sir Isaac Newton created a new design for telescopes, astronomers invented yet another way to study one particular star...our own sun. Solar tower telescopes are both productive astronomical instruments, and eye-catching, too!


San Gabriel Mountains, California, USA
Longitude: 118°, 3.4 minutes West
Latitude: 34°, 13.6 minutes North
Elevation: 5715 feet (1742 meters)


First used while still under construction in 1907. Observations made on June 26, 1908, after the telescope was completed, showed unambiguous evidence for a magnetic field on the sun. This was the first observation of an extraterrestrial magnetic field. The 60-foot tower was the world's most sensitive solar telescope in its day.

The tower construction was finished in 1910, and observations began in 1911. The 150-foot tower eclipsed the 60-foot tower as the world's most powerful solar telescope, and remained so until the completion of the McMath Solar Telescope at Kitt Peak in 1962.


Currently used for studies in high-resolution spectroscopy, helioseismology, magnetograms, and dopplergrams.



Image Gallery:

Photo Credit:

Lou Mayo

Related Mount Wilson Links

Technology Through Time Bulletin Board Activity

This bulletin board activity is designed to focus student attention on the role that sun watching has played in humankind's survival through time. As part of this display you may wish to use your own world map ordownload one we have created for you.

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