Dr. Amir Caspi from the SOUTHWEST Research Center in Boulder, Colorado and his team used airplanes with unique infrared cameras that were developed in general to monitor the shuttle launches after the Columbia disaster to photograph the solar eclipse from a height of 15 kilometers.
For most viewers of the August 21, 2017 solar eclipse - the eclipse will last less than two and a half minutes, but for one group of NASA-funded scientists, the eclipse will last more than seven minutes. Their secret is to fly following the shadow of the moon in two WB-57F jet planes equipped with special equipment.
Amir Caspi, a senior researcher at the Southwest Research Institute in Boulder, Colorado, and his team will use two of NASA's WB-57F research aircraft to chase the darkness across the US on August 21. After installing twin telescopes on the noses of the planes, Caspi and his team want to capture the clearest images of the sun's outer atmosphere - the Atara, as well as the first ever thermal images of the planet Mercury, as well as reveal how the temperature changes on the surface of the Earth during the solar eclipse.
"These may be the best observations of phenomena that occur with high frequency in the corona," says Dan Seaton, of the University of Colorado at Boulder and a co-researcher on the project. "Extending the observation time and raising it to very high altitudes may allow us to see events or to track light frequencies that would be invisible in the almost two minutes of observations from the ground."
The total eclipse time will provide a rare opportunity for scientists to study the Sun, especially its atmosphere when the Moon completely covers the Sun and perfectly blocks its light during a solar eclipse. The corona is weak and only during a solar eclipse will it be possible to see it against the background of the dark sky. NASA is funding 11 science projects across the Americas so scientists can take advantage of the unique astronomical event to learn more about the Sun and its effects on Earth's upper atmosphere.
Composite image of WB-57F aircraft and eclipse. During the solar eclipse, members of a NASA-funded team of scientists will track the Sun's corona using telescopes mounted on two NASA WB-57F research aircraft. This vantage point provides clear advantages over ground-based observations, as demonstrated in this composite image of the aircraft against the backdrop of the 2015 heat wave in the Faroe Islands. Image: NASA / Faroe Islands / SWRI
The corona heats up to a temperature of millions of degrees, but the lower atmospheric layers such as the photosphere - the visible surface of the sun - only reach a few thousand degrees. Scientists are not sure how this reversal happens. One theory suggests that magnetic waves called Alfvén waves transfer energy in the Sun's outer atmosphere, where they are dissipated as heat. Alternatively, tiny explosions, called nanoflares (tiny flames). These explosions are too small and frequent to detect individually, but their collective effect is large, and may release heat into the corona.
Due to technological limitations, no one has yet directly seen these tiny flames, but high-resolution, high-speed images that can be taken from the WB-57F aircraft may reveal their effect on the corona. After the operation, it will be possible to analyze the high definition images, which will be taken thirty times per second, and detect the movement of such waves in the corona to see if the waves are moving towards the surface or away from the surface of the sun, and what their strength is.
"We see the evidence of heating resulting from the flames, but we don't know where they are occurring," Caspi said. "If they occur higher up in the corona, we might expect to see waves moving downward, causing the little explosions to occur and collectively redefine the magnetic fields. In this way, nanoflares may also be the missing link that allows for the chaotic mess of the Sun's magnetic field, and explains why the corona has ordered loops of magnetic fields. The direction and nature of the waves will help us distinguish between the competing models of heating the corona."
The two planes, departing from Ellington Field near NASA's Johnson Space Center in Houston, will view the total eclipse for about three and a half minutes each as they fly over Missouri, Illinois and Tennessee.
In an interview with the Hidan website, Caspi says that he was born in Tel Aviv and left Israel at the age of six. He is 39 years old, and he graduated in 2001 with a bachelor's degree in physics, astronomy, mathematics and computer science at the University of Maryland, and a direct PhD in the Faculty of Physics at the University of California, Berkeley in 2010. The subject of his doctorate was the physics of solar explosion research.
"I work at the Southwest Research Institute, a non-profit scientific institute based in Texas and I am at the branch of the institute in Boulder, Colorado. The reason for opening the branch over 20 years ago was that in Colorado and in Boulder in particular, a lot of space research is being carried out - in particular solar research and aerospace technologies. In my lab in Boulder we do solar research, planets and a little do astrophysics as well. In this framework, I am the main researcher of the solar eclipse observation experiment with the help of NASA's aircraft.
"Most of my research has dealt with solar flares - very energetic events on the Sun and the question of why the corona is very hot - millions of degrees Celsius instead of just thousands of degrees. The explosions on the sun that I've been studying for the last 15 years play a part in this.
Solar eclipses are not uncommon, have you flown these planes before?
"No. This is the first time we do an observation of this kind, during which we use airplanes as a tool to chase the shadow of the moon. Admittedly, there have already been such promotions. Concorde chased a solar eclipse in 1973 but this is the first time the WB-57Fs will make astronomical observations from the air. The devices we use are the best devices with which we have ever observed a solar eclipse from the air and in general this is the first time that NASA has performed such an experiment. These are airplanes with a large wingspan.
Will you fly on one of the planes?
Caspi: "On each plane there will be two crew members who will operate the devices and we will observe what they will show via satellite transmission. Of course I'm sad that I can't be on the plane. This is my first eclipse and I need to see it on TV, because I will be in Texas where the planes will take off from."
What data do you intend to collect?
"In every plane we use two cameras, one in normal light, actually in the green frequency, and the other in infra-red light (5-3 microns). Both will shoot in high resolution at a frequency of 30 times per second.
The plane will fly at a speed of 700 km/h and the shadow at about 2,300 km/h in the area where we will be waiting for it. Because of the flight speed, we can gain about 45% more time for observation. Each plane will see almost four minutes. However, since the planes will cross the shadow at a distance of about 20 km from each other, there will be an overlap of 10-XNUMX seconds when the two planes will be on both sides of the shadow, each plane will get almost four minutes of total eclipse, and with the overlap between them we will have about seven and a half minutes between Both planes.
There is another advantage to flying at a high altitude - 15 km - so we will be above the clouds and will surely see the eclipse in its entirety. At an altitude of 15 kilometers we are above 90-85 percent of the atmosphere, this also increases the quality of the images because the light has to cross a much thinner atmosphere than at ground level, including the eddies at the bottom of the atmosphere.
So why not use supersonic planes?
You can fly at high speed and increase the exposure time to the eclipse, but around a plane moving at supersonic speed, a lot of turbulence is created and this spoils the quality of the images.
If so then why not use three or more planes?
We would like to use a lot of planes but there are currently only two such planes active and the third is dismantled for maintenance. These are planes from the XNUMXs. Also, there are only two devices and we didn't have the budget to buy another device. One of the reasons we are using this plane and these devices is because the devices already existed and it didn't take a lot of money to adapt them for the experiment. These are devices that were built after the Columbia disaster so that NASA planes could 'chase' the shuttle when it took off and also photograph it from a high altitude to make sure that no part fell during take off. We didn't build them for research but we were able to adapt them to our research.
