Welcome guest blogger Dr. David Alexander, Director of the Rice Space Institute.
If there’s one star in the sky that everyone can name — and point to, if needed — it’s the Sun. Kisosen, Wuriupranili, Huitzilopochtli, Bel, Ra, Sol, Apollo — the Sun has many names and has served many purposes for humanity over the ages. As a banisher of night, celestial timekeeper, or navigational aid, the Sun has been a constant presence over the history of humankind, bringing the hope of a new day and the renewal of returning spring.
Even today, in the early years of the 21st century, the Sun is no less important, although perhaps in a very different way. As we increasingly rely on technology in our daily lives, the Sun’s impact on the Earth can be both beautiful and alarming. The Earth is not only bathed in the light from the Sun but is embedded in its atmosphere, and as such is subject to the vagaries of the Sun’s dynamic activity. You might say that when the Sun burps, the Earth reaches for the Lysol.
Spectacular aurora over the city of Tromsø, Norway. Courtesy of Pål Brekke.
The Sun exhibits a wide range of energetic activity over a wide variety of timescales. The most dramatic of these are the so-called solar storms that drive clouds of ionized gas (plasma) outward from the Sun at speeds of millions of miles an hour. When these clouds reach the Earth some one to three days later, the effects can be catastrophic. The immediate effect is energizing the Earth’s magnetic environment in space, leading to a wide array of effects from enhanced atmospheric phenomena such as aurora, with the biggest storms generating aurora as far south as Houston, to increased particle energies and densities in low earth orbit, causing severe hazard for spacecraft and astronauts. In addition, the geomagnetic enhancements caused by these storms can also lead to noticeable effects on the ground, including the disruption of regional electrical grids with power outages being a not uncommon occurrence.
Today, a flotilla of spacecraft and a battalion of ground-based observatories are constantly monitoring the Sun across the electromagnetic spectrum and measuring the changing properties of the solar atmosphere, its magnetic field, and flow speed. Solar scientists use this huge wealth of information to generate an understanding of the physical processes that govern the solar variability and how the effects of this variability propagate through space and ultimately interact with the Earth.
Dr. PĂĄl Brekke
On Thursday, Nov. 15, the Houston Museum of Natural Science, the Rice Space Institute and the Royal Norwegian Consulate host solar physicist and author Dr. Pål Brekke of the Norwegian Space Centre for a lecture in the Museum’s Wortham Giant Screen Theatre as part of Transatlantic Science Week 2012. Dr. Brekke will present a visually spectacular tour of the solar atmosphere and the geomagnetic phenomena that it generates. So please, join us as we celebrate Apollo, the Sun, in all his celestial glory as he burps his way through the 21st century. Tickets are $18 and may be purchased in advance here.
About our guest blogger: Â
Dr. David Alexander is a Professor of Physics and Astronomy and Director of the Rice Space Institute. He is Chair of the Solar Physics Division of the American Astronomical Society and the Solar Heliospheric and Interplanetary Environment (SHINE) program. He received the Presidential Early Career Award for Scientists and Engineers in 2004 and was appointed a Kavli Frontiers Fellow in 2006 by the National Academy of Sciences. He is author of The Sun, part of the Greenwood Press Guides to the Universe series.
