A total solar eclipse is coming to the USA – an experience of a lifetime… and a half. The last time a total eclipse crossed the entire continent was 99 years ago.
This will be the most extensive eclipse the US has seen in nearly a century, and the hype and momentum are building. The whole of North America will experience some degree of eclipse on 21 August 2017, with the path of totality tracking from the north-western to the south-eastern USA. Even areas across South America, Africa, and Europe will experience a partial eclipse.
In order to make the most of the event, NASA has more than 50 high-altitude balloons, 11 NASA and NOAA satellites, and the international space station all trained on the eclipse. Scientists across the country are poised to record atmospheric radiant energy both on the ground and spacecraft – an opportunity that has never been exploited prior to this event. NASA is even enlisting citizen scientists to report temperature and cloud cover data through their Globe Observer program and app from anyone in North America.
But that’s not all – NASA has fitted two jets with telescopes and is sending them more than 15,000 m into the stratosphere to obtain photographs. These photographs are anticipated to be the best quality images ever obtained of the Sun’s outer atmosphere, the corona. Those on the ground in the pathway of the eclipse will experience about two minutes of darkness, but at their position in the stratosphere, scientists will have about three and a half minutes to photograph the eclipse and about an hour to photograph Mercury while light levels are still dim. Photographs of the Sun will be primarily visible light, as opposed to the UV light photographs taken by NASA’s space-based telescopes. The cameras also have the capacity to take 30 photographs per second, which is about three times faster than your Nikon.
If successful, the first ever infrared images of Mercury will also be obtained. Mercury’s proximity to the Sun make it a difficult target for astronomers under normal, non-eclipse conditions to view; the planet hovers near the horizon for mid-to high-latitude observers, which means light and greater thickness of atmosphere at that low angle interfere with observations. Making matters worse, the world’s most powerful telescope, the Hubble Space Telescope, is expressly banned from making observations due to the risk of frying the optical systems if the telescope were to stray onto the Sun.
If NASA can pull this off, they will once again contribute to the ever-increasing list of discoveries and breakthroughs attributed to solar eclipse observations, including Einstein’s theory of relativity in 1919.
Let’s hope for clear skies.