NASA Launching New Sun Observing Spacecraft Thursday
July 4, 2012

NASA Launching New Sun Observing Spacecraft Thursday

Lee Rannals for - Your Universe Online

While the nation shoots off plenty of fireworks for the Fourth of July, NASA will be sending off its own rocket the next day.

The space agency will be launching its Solar Ultraviolet Magnetograph Investigation (SUMI) on Thursday to study the magnetic fields on the sun.

SUMI will set out to study the constantly changing magnetic fields in an area of the sun's low atmosphere called the chromosphere.

These magnetic fields lie at the heart of how the sun can create huge explosions of light, like solar flares and eruptions of particles like coronal mass ejections (CMEs).

"What's novel with this instrument is that it observes ultraviolet light, when all the others look at infrared or visible light," Jonathan Cirtain, a solar scientist at NASA's Marshall Space Flight Center, said in a prepared statement. "Those wavelengths of light correspond to the lowest levels in the sun's atmosphere, but SUMI will look at locations higher in the chromosphere."

The higher layer of the chromosphere is known as the transition region, because the chromosphere transitions there into the part of the sun's atmosphere called the corona. NASA said this region is dominated by the magnetic fields, in which solar material heats up dramatically forming the corona and the base of the solar wind.

According to the space agency, understanding the structure of the magnetic fields in the transition region will allow scientists to understand how the corona is heated and how the solar wind is formed.

The area of the sun is also believed to be where flare accelerated particles originate from, so understanding more about the process can help predict eruptions on the sun.

SUMI will be observing the ultraviolet light emitted from two types of atoms on the sun, Magnesium 2 and Carbon 4.

The spacecraft will help scientists measure the original strength and direction of the magnetic fields, and create a three-dimensional magnetic map of the region.

NASA said this trip for SUMI is "largely" a test flight to make sure it´s instruments work, and to assess possible improvements. The instrument flew in July 2010, but experienced a higher G-force than expected, which broke screws holding the main mirror in place so it was unable to gather accurate data.

"With the knowledge we get from a successful SUMI mission, we can go on to build space-based instrumentation that will help us understand the processes that form flares and CME's and help us predict space weather," Cirtain said.

SUMI will be launching from White Sands Missile Range in New Mexico on a Black Brant rocket. The flight to space will last a total of eight minutes.

Image 2 (below): The chromosphere is a narrow layer above the photosphere that raises in temperature with height. Normally, it can't be seen by the naked eye because the light from the photosphere of the Sun overpowers it. The coloring of the chromosphere (deep red) is caused by the immense hydrogen supply it contains. Credit: NASA