- The total solar eclipse of August 21 will track eastward across the US starting around 9 a.m. PDT.
- NASA will fly "eclipse jets" to make totality — when the moon blocks out the sun — last nearly three times as long.
- The jets will use telescopes to study the sun's corona, or outer atmosphere.
The total solar eclipse of August 21 will be the first in nearly 100 years to cut across the entire continental United States.
For most Americans in the path of the eclipse's umbra — where the moon blocks out the sun and casts its darkest shadow — the strange phenomenon of totality will last about 2 minutes 30 seconds as the eclipse tracks from west to east.
In the US, the eclipse is projected to begin around 9 a.m. PDT in Oregon and end around 4 p.m. EDT in South Carolina. (Figure out the exact time for your viewing location with NASA's interactive eclipse map.)
But NASA-funded scientists at the Southwest Research Institute in Boulder, Colorado, have a clever plan to beat any potential cloudy weather conditions and extend the duration of totality to about seven minutes — nearly triple the time seen on the ground.
Part of the team, led by the space scientist Amir Caspi, will fly inside two of NASA's high-speed "eclipse jets" and chase the shadow as it moves east.
The expedition isn't a pleasure cruise — it's one of 11 research projects NASA has funded in advance of the total solar eclipse.
How to chase a total solar eclipse
Each WB-57F research aircraft, as eclipse jets are officially called, will take off from Ellington Field, which is located near NASA's Johnson Space Center in Houston, Texas.
Once they reach about 50,000 feet, they'll make their way over Missouri, Illinois, and Tennessee as they chase the umbra.
Each aircraft has a suite of sensitive instruments mounted on its nose. One is a pair of telescopes, which the institute's researchers will point at the sun to record what may be the clearest photos of the sun's corona, or outer atmosphere.
The corona is millions of degrees hotter than the surface of the sun, which is about 10,000 degrees Fahrenheit, and scientists don't fully understand why.
Part of the challenge is that the corona is difficult to study. It's dramatically dimmer than our star's main disk, and instruments in space like NASA's Solar Dynamics Observatory (which has hardware that's now more than seven years old) can't record the phenomenon as well as more recent camera models.
"The problem is that SDO doesn't image quickly enough ... for what we are trying to study, and it also doesn't look far enough away from the solar surface," Caspi told Business Insider in an email.
But from Earth, the moon happens to be exactly the size of the sun's disk. So when the moon passes in front of the sun, it will reveal the wispy corona extending millions of miles from the solar surface deep into space — and allow scientists to record the scene with modern gear.
Caspi and his team will mainly be looking for a rarely seen, high-speed phenomenon called Alfvén waves. Such waves were discovered in 2007 and may be the key to shuttling heat from the sun's surface to its corona.
"Extending the observing time and going to very high altitude might allow us to see a few events or track waves that would be essentially invisible in just two minutes of observations from the ground," Dan Seaton, a coinvestigator of the project, said in a NASA press release on Tuesday.
total solar eclipse corona solar sun atmosphere nasa druckmueller
The sun's outer atmosphere, or corona, during a total solar eclipse. M. Druckmüller/NASA
In addition to studying Alfvén waves, researchers plan to point the telescopes on each jet toward Mercury. They'll take those observations before and after totality, when the sky is still mostly dark and the telescopes can map Mercury's surface temperatures.
According to NASA, those measurements could help reveal the planet's soil composition and "give scientists insight into how Mercury and other rocky planets may have formed."
Read the original article on Tech Insider. Copyright 2017.
.ow watch: A solar eclipse will be visible across the entire US for the first time in 99 years, here's how to make the most of it