NASA Solar Dynamics Observatory spots giant dark area on Sun called coronal hole
Q. NASA’s solar dynamics observatory has discovered a dark giant area on the upper half of the Sun. What is it called?- Published on 01 Jun 16a. Coronal Hole
b. Coronal Shade
c. Coronal Height
d. Coronal Width
ANSWER: Coronal Hole
NASA’s Solar Dynamics Observatory has spotted a giant dark area on the upper half of the Sun known as a coronal hole. Coronal holes are areas on the Sun where the solar magnetic field extends up and out into interplanetary space, sending solar material speeding out in a high-speed stream of solar wind.
- Scientists study these fast solar wind streams because they sometimes interact with Earth’s magnetic field, creating what is called a geomagnetic storm, which can expose satellites to radiation and interfere with communications signals.
- Coronal holes are low-density regions of the Sun’s atmosphere, known as the corona. They contain little solar material and have lower temperatures, thus appearing much darker than their surroundings, researchers said.
- Coronal holes are visible in certain types of extreme ultraviolet light, which is typically invisible to our eyes.
