#SUN CORONA EXPERIMENT MOVIE#
#SUN CORONA EXPERIMENT FULL#

The probe will swoop within 6.4 million kilometers of the sun and take the first direct measurements of the corona - and perhaps figure out more precisely where the corona becomes the solar wind.įor now, the STEREO observations “are just tantalizing hints at an entire new set of phenomena,” DeForest says. That’s still a big range, but NASA’s Parker Solar Probe spacecraft, scheduled to launch in 2018, will fly right through that boundary. The researchers also found that the corona probably fades into the solar wind between 14 million and 56 million kilometers away from the sun - about 10 to 40 times the sun’s diameter. “There’s almost certainly reconnection in the outer corona.” “It turns out the apparent smoothness is a reflection of our instruments, not the corona itself,” DeForest says.

#SUN CORONA EXPERIMENT FULL#

Surprisingly, the team found that the outer corona is full of moving blobs and fine streams of plasma that vary in density by a factor of 10, suggesting that the magnetic field lines there are moving and merging more than scientists thought. The researchers also processed the resulting images in a new way to bring those changes into focus. The data revealed structures, including blobs and knots, in that outer zone that were not apparent in earlier movies.ĭeForest and colleagues collected data for three days with STEREO in 2014 to gain more detail about small-scale changes in the outer corona than previously obtained.

#SUN CORONA EXPERIMENT MOVIE#

“Using STEREO, we’ve recently been able to drill in deeply enough to see the transition at the outer edge of the corona, where the dynamics change from what we might call coronal plasma to what we might call the young solar wind plasma.”ĭEEP VIEW This movie was made using three days of data from NASA’s STEREO spacecraft, which blocked out the sun (center) to see the outer corona better. “That’s changed,” solar physicist Craig DeForest of the Southwest Research Institute in Boulder, Colo., said at the AGU meeting. What’s more, physicists couldn’t tell where the boundary between the corona and the solar wind began, which might help to find that missing energy source.

To explain that smoothness, field lines would have to keep their distance from each other without a lot of reconnection.

Reconnection releases energy and helps move plasma around, so the process could be important to heating the corona and driving solar wind.īut in the best observations until now, the outer corona appeared smooth and uniform. And they don’t understand why the corona, which sizzles at several million degrees Celsius, has such higher temperatures than the solar surface, which chills at a mere 5,500° C ( SN Online: 8/20/17).īoth problems might be cleared up by better understanding an energetic process called reconnection, which happens when magnetic field lines merge when they get too close to each other. At a certain distance from the sun, though, that plasma escapes the corona and streams through the solar system as the solar wind, a constant flow of charged particles that pummels the planets, including Earth ( SN Online: 8/18/17).īut solar physicists don’t know where the plasma gets enough energy to accelerate away from the massive, magnetic sun. Spectral broadening indicates a marked progressive increase in plasma irregularities with decreasing ray altitude at scales between about 1 and 100 km.The corona is made up of charged plasma, which roils in famous loops and fans that follow magnetic field lines emerging from the surface of the sun ( SN Online: 8/17/17). Power spectra of the 3.5- and 13-cm signals at a heliocentric radial distance of about 2 R sub s have a 1/2 power width of several hundred hertz and vary sharply with proximate geometric miss distance. Observations of integrated plasma density near the south pole of the sun generally agree with a model of the corona which has an 8:1 decrease in plasma density from the equator to the pole. The data can be used to determine the plasma density integrated along the radio path, the velocity of density irregularities in the coronal plasma, and the spectrum of the density fluctuations in the plasma. Data were obtained within at least 0.3 and 0.8 R sub s of the photosphere at the 3.5- and 13-cm wavelengths, respectively. During the conjunction period, coherent 3.5- and 13-cm wavelength radio waves from the orbiters passed through the solar corona and were received with the 64-m antennas of the NASA Deep Space Network. The Viking solar corona experiment The 1976 Mars solar conjunction resulted in complete occultations of the Viking spacecraft by the sun at solar minimum.

Sun corona experiment