SDO Observes Massive Eruption And Scorching Rain

Just last week, scientists working with NASA's new Solar Dynamics Observatory (SDO) released the most astonishing movies of the sun anyone had ever seen. Now, they're doing it again.

"SDO has just observed a massive eruption on the sun-one of the biggest in years," says Lika Guhathakurta of NASA headquarters in Washington DC. "The footage is not only dramatic, but also could solve a longstanding mystery of solar physics."

Karel Schrijver of Lockheed Martin's Solar and Astrophysics Lab is leading the analysis. "We can see a billion tons of magnetized plasma blasting into space while debris from the explosion falls back onto the sun surface. These may be our best data yet."

The movie, recorded on April 19th, spans four hours of actual time and more than 100,000 km of linear space. "It's huge," says Schrijver. Indeed, the entire planet Earth could fit between the plasma streamers with room to spare.

Astronomers have seen eruptions like this before, but rarely so large and never in such fluid detail. As science team member Alan Title of Lockheed Martin pointed out at last week's press conference, "no other telescope comes close to the combined spatial, temporal and spectral resolution of SDO."

Schrijver says his favorite part of the movie is the coronal rain. "Blobs of plasma are falling back to the surface of the sun, making bright splashes where they hit," he explains. "This is a phenomenon I've been studying for years."

Coronal rain has long been a mystery. It's not surprising that plasma should fall back to the sun. After all, the sun's gravity is powerful. The puzzle of coronal rain is how slowly it seems to fall. "The sun's gravity should be pulling the material down much faster than it actually moves. What's slowing the descent?" he wonders.

For the first time, SDO provides an answer.

"The rain appears to be buoyed by a 'cushion' of hot gas," says Schrijver. "Previous observatories couldn't see it, but it is there."

One of SDO's game-changing capabilities is temperature sensing. Using an array of ultraviolet telescopes called the Atmospheric Imaging Assembly (AIA), the observatory can remotely measure the temperature of gas in the sun's atmosphere. Coronal rain turns out to be relatively cool-"only" 60,000 K. When the rains falls, it is supported, in part, by an underlying cushion of much hotter material, between 1,000,000 and 2,200,000 K.

"You can see the hot gas in the color-coded temperature movie," says Schrijver. "Cool material is red, hotter material is blue-green. The hot gas effectively slows the descent of the coronal rain."

Dick Fisher, the head of NASA's Heliophysics Division in Washington DC, has been working in solar physics for nearly forty years. "In all that time," he says, "I've never seen images like this."

"I wonder, what will next week bring?"

Nasa's Solar Dynamics Observatory returns first images

The first public release of images from the satellite record huge explosions and great looping prominences of gas.

The observatory's super-fine resolution is expected to help scientists get a better understanding of what drives solar activity.

Launched in February on an Atlas rocket from Cape Canaveral, SDO is expected to operate for at least five years.

Researchers hope in this time to go a long way towards their eventual goal of being able to forecast the effects of the Sun's behaviour on Earth.

Solar activity has a profound influence on our planet. Huge eruptions of charged particles and the emission of intense radiation can disrupt satellite, communication and power systems, and pose a serious health risk to astronauts.

Scientists working on SDO say they are thrilled with the quality of the data received so far.

"When we see these fantastic images, even hard-core solar physicists like myself are struck with awe, literally," said Lika Guhathakurta, the SDO programme scientist at Nasa Headquarters.

SDO is equipped with three instruments to investigate the physics at work inside, on the surface and in the atmosphere of the Sun.

The probe views the entire solar disc with a resolution 10 times better than the average high-definition television camera. This allows it to pick out features on the surface and in the atmosphere that are as small as 350km across.

The pictures are also acquired at a rapid rate, every few seconds.

In addition, the different wavelengths in which the instruments operate mean scientists can study the Sun's atmosphere layer by layer.

A key quest will be to probe the inner workings of the solar dynamo, the deep network of plasma currents that generates the Sun's tangled and sometimes explosive magnetic field.

It is the dynamo that ultimately lies behind all forms of solar activity, from the solar flares that explode in the Sun's atmosphere to the relatively cool patches, or sunspots, that pock the solar disc and wander across its surface for days or even weeks.

"The SDO images are stunning and the level of detail they reveal will undoubtedly lead to a new branch of research into how the fine-scale solar magnetic fields form and evolve, leading to a much, much better understanding of how solar activity develops," said co-investigator Richard Harrison from the UK's Rutherford Appleton Laboratory (RAL).

"It's like looking at the details of our star through a microscope," he told BBC News.

And Dr Guhathakurta added: "It's thought that [SDO] is going to revolutionise heliophysics much as the Hubble Space Telescope has revolutionised astrophysics and cosmology, which is true. There is however a very key difference. While Hubble is designed to observe almost everything in the cosmos, SDO is designed to study only one thing and that is our very own star. It is tailor-made for the study of Sun star."

SDO's three remote-sensing instruments are:

Helioseismic and Magnetic Imager (HMI) : will study the motions and magnetic fields at the Sun's surface, or photosphere, to determine what is happening inside the star. It will try to decipher the physics of the solar dynamo - the very source of the Sun's activity. The dynamo regulates all forms of solar activity from the lightning-fast eruptions of solar flares to the slow decadal undulations of the sunspot cycle.

Atmospheric Imaging Assembly (AIA) : is a suite of four telescopes that will image the corona, the outer layer of the Sun's atmosphere. The AIA filters cover 10 different wavelength bands, or colours, from the extreme ultraviolet to the visible. It will see details as small as 725km across. These images will be acquired every 10 seconds. Previous observatories have taken pictures at best every few minutes.

Extreme Ultraviolet Variability Experiment (EVE) : will measure the Sun's energy output in extreme-ultraviolet (E-UV) wavelengths (this is called irradiance) with unprecedented precision. The Sun is at its most variable in the E-UV. E-UV rays can break apart atoms and molecules in the Earth's upper-atmosphere, creating a layer of ions that can severely disturb radio signals.

The UK has a prominent role in the mission through the Rutherford Appleton Laboratory in Didcot; the e2v company in Chelmsford which supplied CCD camera detectors; the Mullard Space Science Laboratory in London; the University of Warwick; the University of Sheffield; and the University of Central Lancashire (UCLan) in Preston.

UCLan handles the SDO data coming into the UK. With the mission producing some 1.5 tera-bytes per day, it requires a dedicated gateway for scientists to exploit.

Source:- SDO

NASA Successfully Launches a New Eye on the Sun

CAPE CANAVERAL, Fla. - NASA's Solar Dynamics Observatory, or SDO, lifted off Thursday from Cape Canaveral Air Force Station's Launch Complex 41 on a first-of-a-kind mission to reveal the sun's inner workings in unprecedented detail. The launch aboard an Atlas V rocket occurred at 10:23 a.m. EST.

The most technologically advanced of NASA's heliophysics spacecraft, SDO will take images of the sun every 0.75 seconds and daily send back about 1.5 terabytes of data to Earth -- the equivalent of streaming 380 full-length movies.

"This is going to be sensational," said Richard R. Fisher, director of the Heliophysics Division at NASA Headquarters in Washington. "SDO is going to make a huge step forward in our understanding of the sun and its effects on life and society."

The sun's dynamic processes affect everyone and everything on Earth. SDO will explore activity on the sun that can disable satellites, cause power grid failures, and disrupt GPS communications. SDO also will provide a better understanding of the role the sun plays in Earth's atmospheric chemistry and climate.

SDO is the crown jewel in a fleet of NASA missions to study our sun. The mission is the cornerstone of a NASA science program called Living With A Star. This program will provide new understanding and information concerning the sun and solar system that directly affect Earth, its inhabitants and technology.

The SDO project is managed at NASA's Goddard Space Flight Center in Greenbelt, Md. NASA's Launch Services Program at Kennedy Space Center managed the payload integration and launch.

For launch coverage, briefing materials, and multimedia, visit: http://www.nasa.gov/mission_pages/sdo/news/briefing-materials-20100209.html

For more information about the SDO mission, visit: http://www.nasa.gov/sdo