00:03المترجم للقناة
00:03The 2016 Transit of Mercury
00:06presented by Science at NASA
00:09Solar scientists
00:10are accustomed to seeing spots
00:12on the sun, irregular
00:13islands of magnetism that sometimes erupt
00:16producing strong solar flares
00:17On May 9, 2016
00:20they will see a spot of a very
00:21different kind, a dark circle
00:23moving across the solar disk
00:25This spot is no ordinary
00:27sunspot. It's the planet Mercury
00:29making a rare transit of the sun
00:32Mercury passes directly
00:34between the sun and Earth about 13
00:36times every century
00:37The last time it happened was 10 years ago
00:39in 2006, and the next time
00:42will be November 11, 2019
00:45This year's transit
00:46will be widely visible for most of Earth
00:47including the Americas, the
00:49Atlantic and Pacific Oceans, Europe
00:51Africa, and much of Asia
00:54In the USA, it begins
00:56on the morning of Monday, May 9
00:57around 7.15 a.m.
00:59Eastern Daylight Time
01:00This means it begins before sunrise
01:02on the West Coast, but that's no problem
01:04The transit lasts for more than 7 hours
01:07so Mercury will still be gliding across
01:09the solar disk when the sun comes up
01:11over places like California and Alaska
01:13Everyone in the USA can experience
01:16the event
01:17Caution! Take care when viewing the transit
01:20Mercury's tiny disk
01:22jet black and perfectly round
01:24covers only a tiny fraction
01:25of the sun's blinding surface
01:28Looking at the sun with unprotected eyes
01:30on May 9 is as dangerous as ever
01:31With the proper filter, however
01:33viewing the transit of Mercury can be a
01:35marvelous experience
01:36A telescope with a safe solar filter will be
01:39required to see the tiny disk of Mercury
01:41crawling across the face of the sun
01:44Mercury is too small to be seen without
01:46magnification
01:47You may wish to call your local
01:49astronomy club and ask if they have
01:51a solar telescope
01:51Amateur astronomers love to show off the heavens
01:54The event will provide volunteers
01:56the opportunity to bring their scopes
01:58to classrooms for the transit
01:59If you can't find access to a good telescope
02:02NASA's Solar Dynamics Observatory
02:05will also witness the entire transit
02:07and make it available in real time
02:09on its website
02:10NASA scientists Rosemary Killen
02:12and colleagues plan to use the transit
02:14to study Mercury's ultra-thin atmosphere
02:16or exosphere
02:17The atoms in Mercury's exosphere
02:20come from the surface of Mercury itself
02:22They are blasted into space
02:24by solar radiation, solar wind bombardment, and meteoroids
02:28This gives Mercury a comet-like tail
02:31stretched out as long as 1.2 million miles
02:34You cannot see this tail during the transit, however
02:38Killen says, when Mercury is in front of the sun
02:40we can study the exosphere close to the planet
02:43Sodium in the exosphere
02:44absorbs and re-emits a yellow-orange color
02:47from sunlight
02:47and by measuring that absorption
02:49we can learn about the density of gas there
02:52She says, we will be observing the transit
02:55from the National Solar Observatory
02:57or NSO
02:58in Sunspot, New Mexico
03:00Killen, Carl Schmitt of Latmos
03:02at the French National Research Agency
03:04and Kevin Reardon of the NSO
03:06will be on site making observations
03:09The transit of Mercury offers something to professional astronomers
03:12and backyard sky watchers alike
03:14from scientific discovery
03:16to simple wonder
03:17Mark your calendar for May 9th
03:19and enjoy the show
03:21For more news about rare events in the heavens
03:23stay tuned to science.nasa.gov
03:27Thank you
03:27Thank you
03:27Thank you
03:27Thank you
Comments