Sun Corona Current Affairs - 2019
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Scientists from NASA for first time are planning to chase the shadow of the moon using two of NASA’s WB-57F research jets during the upcoming total solar eclipse in US. The purpose of the chase is to capture the clearest ever images of the Sun’s outer atmosphere.
The research jets (planes) will have twin telescopes mounted on the noses of the planes to capture clearest images of Sun’s corona to date. They will also undertake first-ever thermal images of Mercury to reveal how temperature varies across the planet’s surface.
Need for research
The corona of sun (gaseous envelope surrounding sun) is heated to millions of degrees, but the lower atmospheric layers like the photosphere are only heated to a few thousand degrees. So far, scientists are not sure how this inversion happens. One theory proposes micro explosions, termed nanoflares (too small and frequent to detect individually) with a large collective effect might be releasing enarmous heat into the corona.
The total solar eclipse will provide rare opportunity for scientists to study the sun, particularly its atmosphere. During this eclipse, moon will completely cover the sun and perfectly blocking its light so that faint corona is easily seen against the dark sky.
The two research planes will observe the total eclipse for about three and a half minutes each. The vantage point on planes will provide distinct advantages over ground-based observations as no one has yet directly seen nanoflares. Moreover, the high-resolution and high-speed images to be taken from the WB-57F jets might also reveal their effects on the corona.
The planes will also take observations of Mercury 30 minutes before and after sky is still relatively dark. These images will be taken in the infrared and will be the first attempt to map the variation of temperature across the surface of the planet.
The planes will be flying high in the stratosphere to avoid Earth’s atmosphere for improving image quality. The sky will be also 20–30 times darker at the altitude where planes will be flying than as seen from the ground. There is also much less atmospheric turbulence, that will allow fine structures and motions in sun’s corona to be visible.