NASA's Solar Sentinels -Predicting Future Behavior of the Sun

"What if you woke up one morning and found your whole planet had been swallowed by the atmosphere of a star?

"Get out of bed, look out the window. Auroras are dancing along the horizon. Dark sunspots crackle overhead—each little 'pop' more powerful than a nuclear bomb. On TV, a weather forecaster warns astronauts, "a solar flare is sure to erupt," although he can't say exactly when. Moments later, the satellite signal begins to flicker.

"Where is this place?

"Welcome to planet Earth."

Lika Guhathakurta, program manager of NASA's Living with a Star program.

"It's true. We live inside the atmosphere of the sun," says Lika Guhathakurta, program manager of NASA's Living with a Star (LWS) program, a program set up to broaden our understanding of just what it means to go gallivanting across space.

One of the nice things about living on Earth, is that for the most part, we don’t have to deal with the Sun's more eccentric activities. Solar winds and radiation storms are dealt with by Earth’s magnetic field, and only when a massive coronal ejection or sun flare occurs do we notice anything, when all our technology starts turning off.

But "we're not staying on Earth," says Guhathakurta. "Civilization is spreading into space." And out in space, there is no nice cushy magnetic field to keep us safe.

So in 2001, the Living with a Star program was set up, so that we could further understand the effects that our sun has on the space around it. With over 500 active satellites trundling around Earth, a space station, and goals to head to the Moon and Mars, such information is going to prove vital in the future. "If we're going to live inside the sun's atmosphere, we need to learn more about it—especially how to predict the storms," says Guhathakurta.

And just as studying weather on Earth requires a mass of satellites in the atmosphere to measure readings, LWS is “going to launch a fleet of 'weather stations' – spacecraft that observe different aspects of sun’s atmosphere,” into orbit to complete its five separate missions.

#1 - The Solar Dynamics Observatory (SDO): "Get ready for jaw-dropping photos," says Guhathakurta. A camera onboard the observatory will take HDTV quality photographs of sunspots and solar flares, revealing the onset of storms in never-before-seen detail.

Pictures alone, however, do not tell the whole story. NASA solar physicist Alex Pevtsov explains: "Solar activity is a bit like a puppet show. If you want to understand the motion of the puppets, you need to see the strings. On the sun, the 'invisible strings' are magnetic fields; they penetrate the sun's atmosphere, guiding the flow of heat and orchestrating mighty explosions. SDO will be able to produce detailed maps of magnetism on the sun, revealing the strings for all to see."

But who (or what) is pulling the strings? "That would be the sun's magnetic dynamo," says Pevtsov. "It lies hidden beneath the surface of the sun." Fortunately, SDO can look down there, too. The technique is called helioseismic imaging. By monitoring the sun's vibrating surface, SDO can probe the stellar interior in much the same way that geologists use seismic waves from earthquakes to probe inside Earth. In this way, mission scientists hope to map the ebb and flow of the sun's inner magnetic dynamo, the root of all solar activity.

Status: SDO is built and almost ready to go. "Right now, SDO is in a thermal vacuum chamber getting tested for the rough ride to space."

#2 - Solar Probe Plus: "This could be the most exciting mission of all." It is a heat-resistant spacecraft designed to plunge deep into the sun’s atmosphere where it can sample solar wind and magnetic fields in situ. "No spacecraft has ever been as close to the sun as Solar Probe Plus will go, only 7 million km from the surface. That's unexplored territory, and we expect to learn a great deal about the sun's atmosphere by going there."

Status: Solar Probe Plus is still in an early design phase, called "pre-phase A" at NASA Headquarters. It is expected to launch no earlier than 2015.

#3 - Solar Sentinels: "We're going to surround the sun," says Guhathakurta. Three well-instrumented probes from NASA and a fourth (the Solar Orbiter) from the European Space Agency will station themselves around the sun's equator, providing the first truly global view of solar activity. "Imagine trying to figure out Earth's climate by watching only one side of the planet. Impossible! Yet that's what we've been doing with the sun." The one-sided view from Earth limits studies of solar climate and weather—a problem Solar Sentinels will remedy.

Status: "We've just finished the Science and Technology Definition Team report, which lays out the whole strategy for Solar Sentinels." Launch is expected no earlier than 2015.

#4 - The Radiation Belt Storm Probes: "There's no point in studying the sun if you don't understand what it does to Earth," declares Guhathakurta. This mission makes the crucial Sun-Earth connection. Wisps of the sun's atmosphere can become trapped by Earth's magnetic field, inside radiation belts, where energetic particles lie in wait for astronauts and satellites trying to leave or simply orbit the planet. The Radiation Belt Storm Probes (two of them) will explore these regions and discover how they are populated and energized by space weather.

Status: The two probes are under construction at the Johns Hopkins Applied Physics Lab and slated for launch no earlier than 2011.

#5 - The Ionosphere-Thermosphere Storm Probes: Two more probes will orbit Earth and study the upper reaches of Earth’s atmosphere where air makes "first contact" with solar UV radiation. This is a realm of electrically charged particles that strongly affect the propagation of radio waves, influencing almost all forms of telecommunication and GPS navigation. It is also a place where the atmosphere breathes in and out in response to changes in solar UV heating. An outward breath can envelop and drag down satellites, while an inward breath decreases the drag. The Ionosphere-Thermosphere Storm Probes will monitor the response of this layer to all kinds of solar storms.

Status: "This is an important mission, but not yet funded," says Guhathakurta. "Right now we have our hands full with the others."

As humans continue to expand their knowledge of the universe, the Sun is going to receive a lot more focus. And you can guarantee that, once a year, we’re going to see a newspaper headline opining about visiting the Sun during the night.

Posted by Josh Hill. Adapted from NASA Press Release

http://www.physorg.com/news138457883.html
http://science.nasa.gov/headlines/y2008/19aug_lws.htm

Comments

[Ariel]

wow. this information is absolutely crazy.

[Ariel]

wow. this information is absolutely crazy.

[Ariel]

wow. this information is absolutely crazy.

[Ceren Burcak]

It's indeed interesting; only before a while everyone said that even a certain major distance from the surface of sun was so burning that you couldn't approach it. But now we're considering to discover the unrevealed parts of the sun and go quite near it. Actullay I'm very curious about the time after 2020's.

[radyo dinle]

thanks for this great post