Looking at the Sun in a New Light

October 12, 2011 · 0 comments

With orbiting observatories and solar probes now available to scientists, it might seem that studying the Sun (and its effects on weather and climate) has largely shifted to space-based technology. But in fact, ground-based monitoring of the Sun provides significant opportunities that aren’t possible from space. And the future of looking at the Sun from Earth is primed to become brighter with the recent announcement that the National Solar Observatory (NSO) will be moving to the University of Colorado at Boulder.

The NSO currently operates in two locations: Kitt Peak National Observatory in Arizona and Sacramento Peak Observatory in Arizona. The consolidation of these two locations and the move to Colorado will be a multiyear process, with the actual physical relocation to begin around 2016.

The move will include the deactivation of older telescopes–some of which date to the 1950s–and will coincide with the construction of the Advanced Technology Solar Telescope (ATST), which when completed will be the largest optical solar telescope in the world. The ATST will be located in Hawaii, but the new NSO in Boulder will be the ATST’s science, instrument development, and data analysis center.

The dual projects should result in major advancements for solar exploration from the ground. The ATST will provide “unprecedented resolution and accuracy in studying the finescale magnetic field and solar activity that controls what happens in the solar atmosphere and beyond,” according to the NSO’s Stephen Keil.

Jeff Kuhn of the University of Hawaii explains how the ATST will be valuable in studying the Sun’s magnetic field, which drives much of the sun’s activity:

Most of the changes that happen on the Sun are caused by changes in magnetic fields,  and the ATST is a very specialized instrument that allows us to see those changes, and in fact has a sensitivity to measure changes in the magnetic field at the same kind of magnetic field strength as the . . . magnetic field that exists on the Earth that makes your compass needle work.

The high-resolution images needed to study the Sun’s magnetic field require very large telescopes that are too expensive to send into space. With the development of adaptive optics technology, ground-based observations are now much sharper than in the past, allowing for the study of “extremely small, violently active magnetic fields that control the temperature of the corona, and the solar wind, that produce flares [and] x-ray emission,” according to Eugene Parker of the University of Chicago.

Additionally, ground-based observatories have the capability of not just creating images, but also of making movies that track solar changes on time scales of minutes or even seconds.

The NSO has created a video (available on this page) that explains more about the atmospheric effects of solar activity and other advantages of ground-based solar research.