Know Your Sun

Image Credit: NASA/Jenny Mottar

NASA has just released five new videos called "Mysteries of the Sun". The videos describe the science of the sun and its effects on the solar system and Earth. Scientists study the sun not only to better understand the orb that influences life, but also to study how it sends solar material out into space, filling up the bubble that defines the farthest reaches of the solar system. The sun can also impact Earth's technology: solar storms can affect our communications satellites and cause surges in power lines. These movies cover the breadth of solar, heliospheric, and geospace science, a field known as heliophysics.

The five movies, available online at http://missionscience.nasa.gov/sun and on DVD, cover five areas of heliophysics: Space Weather, Solar Variability, the Heliosphere, Earth's magnetosphere, and Earth's upper atmosphere.

ATREX Mission Successfully Launched

NASA successfully launched five suborbital sounding rockets this morning from its Wallops Flight Facility in Virginia as part of a study of the upper level jet stream. The first rocket was launched at 4:58 a.m. EDT and each subsequent rocket was launched 80 seconds apart.

Launch of a sounding rocket Wallops Island, Virginia early in the morning of March 27. Credit: NASA/Wallops

Each rocket released a chemical tracer that created milky, white clouds at the edge of space. Tracking the way the clouds move can help scientists understand the movement of the winds some 65 miles up in the sky, which in turn will help create better models of the electromagnetic regions of space that can damage man-made satellites and disrupt communications systems.

A Jet Stream Study to Light Up the Sky

Update:  The mission was launched around 5 a.m. March 27.  Some photos are coming soon.

Little is known about the about the atmosphere above 50 miles, yet below where spacecraft orbit.  This is generally known as the Thermosphere above the Mesopause (See the graphic to the left, Image Credit: NASA).  The only way to study this region is with sounding rockets.  Some 35 to 40 feet long, sounding rockets shoot up into the sky for short journeys of eight to ten minutes, allowing scientists to probe difficult-to-reach layers of the atmosphere.

NASA will be conducting an experiment aimed at studying high-level winds near the edge of space at altitudes of 60 to 65 miles.  Winds at this altitude move at speeds of 200 to 300 miles per hour.  To study the winds NASA will release trimethyl aluminum which forms milky, white clouds that allow those on the ground to "see" the winds in space and track them with cameras.

Five sounding rockets will be launched in approximately five minutes to study these high-altitude winds and their intimate connection to the complicated electrical current patterns that surround Earth. First noticed in the 1960s, the winds in this jet stream shouldn't be confused with the lower jet stream located around 30,000 feet, through which passenger jets fly and which is reported in weather forecasts. This rocket experiment is designed to gain a better understanding of the high-altitude winds and help scientists better model the electromagnetic regions of space that can damage man-made satellites and disrupt communications systems. The experiment will also help explain how the effects of atmospheric disturbances in one part of the globe can be transported to other parts of the globe in a mere day or two.

The experiment is known as the Anomalous Transport Rocket Experiment (ATREX).  It is scheduled for 1:30 a.m. on March 15.  The backup dates are March 16 through April 3.  There will be a webcast of the mission beginning 2 1/2 hours prior to launch and can be viewed at: http://sites.wff.nasa.gov/webcast.

Geomagnetic Storm in Progress

The sun erupted late Sunday night with an M8.7 class flare, an earth-directed coronal mass ejection (CME), and a burst of fast moving, highly energetic protons known as a "solar energetic particle" event.  This is producing the strongest radiation storm since September 2005 according to NOAA's Space Weather Prediction Center.

That news was flashed around the globe yesterday in preparation for the arrival of the CME.  It arrived at earth about 15z (11 a.m. ET) this morning.  It does not pose a threat to anyone on the surface, but some planes flying over the poles have been rerouted.

The event was captured by NASA's Solar Dynamics Observatory.  The video shows the eruption toward the end.

From NASA:

What is a solar flare?

 A solar flare is an intense burst of radiation coming from the release of magnetic energy associated with sunspots. Flares are our solar system’s largest explosive events. They are seen as bright areas on the sun and they can last from minutes to hours. We typically see a solar flare by the photons (or light) it releases, at most every wavelength of the spectrum. The primary ways we monitor flares are in x-rays and optical light. Flares are also sites where particles (electrons, protons, and heavier particles) are accelerated.

What is a coronal mass ejection (CME)?

The outer solar atmosphere, the corona, is structured by strong magnetic fields. Where these fields are closed, often above sunspot groups, the confined solar atmosphere can suddenly and violently release bubbles of gas and magnetic fields called coronal mass ejections. A large CME can contain a billion tons of matter that can be accelerated to several million miles per hour in a spectacular explosion. Solar material streams out through the interplanetary medium, impacting any planet or spacecraft in its path. CMEs are sometimes associated with flares but can occur independently.

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This storm is likely to cause enhanced auroral displays tonight as well as some navigational and electrical grid problems.  The potential problems will exist through tomorrow when the storm is expected to subside.

It is rare to see auroras as far south as South Carolina.  However, the chances increase during such storms.  It may be worth watching the skies tonight since they are expected to be clear.  Just be sure to bundle up, because it will be chilly.