NASA spots giant hole enveloping sun
Black hole sun, won鈥檛 you come and wash away the rain....
This week, NASA鈥檚 captured an incredible sight 鈥� a massive dark spot spreading across the sun鈥檚 surface. The astronomical phenomenon, known as a coronal hole, has captivated spectators for its apocalyptic appearance.
But aside from a few cosmic inconveniences, it鈥檚 perfectly harmless.
A coronal hole is a low-density spot in the corona, which is the plasma layer that surrounds our sun. It opens the sun鈥檚 magnetic field to interplanetary space, creating solar wind streams that shoot coronal matter outward.
鈥淭he plasma structures visible in extreme ultraviolet (EUV) imagery are not present in the coronal hole regions, hence their darker appearance,鈥� says Robert Steenburgh, a researcher at the National Oceanic and Atmospheric Administration's聽Space Weather Prediction Center in Boulder, Colo., in an email to 海角大神. 鈥淭he hole is not visible in all types of imagery, [such as] white light images of the sun.鈥�
Coronal holes are a natural phenomenon that occur sporadically, and they鈥檙e generally not a cause for concern despite their chilling appearance. But some effects can still be felt 鈥渄ownstream,鈥� on our side of the solar system.
鈥淒ownstream, you get the phenomenon known as coronal mass ejection (CME), which is a giant plume of billions and billions of tons of plasma that鈥檚 flowing from sun to Earth,鈥� says Bob Weigel, director of the Space Weather Lab at George Mason University in Fairfax, Va., in a phone interview with the Monitor.
The resulting聽聽can interfere with radio signals, disrupt airline communication, and cause GPS errors. In 1989, a geomagnetic storm caused the Hydro-Qu茅bec power network to crash. The resulting blackout affected 6 million people and lasted nine hours.
Space weather also affects machines and humans outside Earth's protective magnetosphere. Astronauts have strict exposure limits to protect themselves from solar particle radiation, which spikes during coronal hole events. A聽 did occur between the Apollo 16 and Apollo 17 missions 鈥� if the timing had been off on either side, astronauts could have experienced 鈥渓ife threatening鈥� particle radiation, according to NASA.聽The high-powered particles emitted from coronal holes can also shorten satellite lifespans.聽
But solar storms aren鈥檛 just a nuisance 鈥� they can also create some pretty spectacular views.
In October, a similar on Earth, NASA reported. For several nights, the multi-colored display was visible to the naked eye. With any luck, this new occurrence might do the same.
But coronal holes and northern lights are nothing new. So why all the hype now?
鈥淚nvestigators working on NASA missions are under constant pressure to generate PR images for NASA public affairs folks to feed out to the public,鈥� says John Mariska, a research professor specializing in space weather at George Mason University, in an email to the Monitor. 鈥淚n my view, there is a tendency to overdo the hype. That being said, trying to inspire young people to consider a career in science is very important to the future of our country.鈥�
