Mercury poised for rare 'transit' across sun's face on Monday

Mercury Set to Cross the Sun in Rare Celestial Event

CAPE CANAVERAL, Fla. (Reuters) - Stargazers will have a rare opportunity on Monday to witness Mercury fly directly across the face of the sun, a sight that unfolds once every 10 years or so, as Earth and its smaller neighboring planet come into perfect alignment.

The best vantage points to observe the celestial event, known to astronomers as a transit, are eastern North America, South America, Western Europe and Africa, assuming clouds are not obscuring the sun. In those regions, the entire transit will occur during daylight hours, according to Sky and Telescope magazine.

But Mercury is too small to see without high-powered binoculars or a telescope, and looking directly at the sun, even with sunglasses, could cause permanent eye damage.

Fortunately NASA and astronomy organizations are providing virtual ringside seats for the show by live-streaming images of the transit in its entirety and providing expert commentary.

RELATED: Other space events occurring in 2016:

2016 space calendar
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Mercury poised for rare 'transit' across sun's face on Monday

January 3, 4 - Quadrantids Meteor Shower

You may still have some leftovers from that New Years Eve when the first meteor shower of the year hits its peak. On Sunday evening you'll have a chance to catch up to 40 meteors per hour at peak, but the shower runs annually from January 1-5. Keep your eye on the constellation Bootes for the best chance of seeing one. 

(Photo via NASA/MSFC/MEO) 

March (date uncertain)

This one will likely be easier to watch on your smartphone via livestream, but sometime in March Astronaut Scott Kelly and Cosmonaut Mikhail Kornienko are scheduled to return to Earth after their groundbreaking "Year in Space" mission on board the International Space Station -- they've already been having a blast.  

(Photo via AOL)

March 9 - Total Solar Eclipse

Skywatchers will be treated to a total solar eclipse in early March. The best views will be seen in central Indonesia and the Pacific Ocean where the sun will be fully blocked. A partial eclipse will be visible in most parts of northern Australia and southeast Asia. If you can't be in that part of the world, keep your eye out for the livestream. 

(Photo via GREG WOOD/AFP/Getty Images)

April 22 - Full Pink Moon

One of many full moons in 2016, the April moon was known by Native American tribes as the Full Pink Moon because it typically shows up when the pink flowers of spring return. This year's will be noteworthy because it coincides with a meteor shower.

(Photo by Franco Origlia/Getty Images)

April 22, 23 - Lyrids Meteor Shower

 The Lyrids shower runs from April 16-25. This year it will peak on the same night as as the full moon, which will make all but the brightest meteors hard to see. For the best chance, keep your eye on the constellation Lyra.

(Photo by Fatma Selma Kocabas Aydin/Anadolu Agency/Getty Images)

May 6, 7 - Eta Aquarids Meteor Shower

You might not know this shower well, but you probably know the celestial body that causes it: Halley's Comet. For those in the Southern Hemisphere, this is a big shower, with up to 60 meteors per hour at its peak. Up north, expect more like 30 meteors per hour. The shower runs from April 19 to May 28 and peaks on the evening of May 6 and coincides with a new moon (no moon) which means darker skies and likely a better show. Look to the constellation Aquarius for this one.

(Photo via NASA)

May 9 - Rare Transit of Mercury Across the Sun

You'll want to find a telescope and good solar filter to check out this view, as Mercury will passes between the Earth and the Sun. This is extremely rare event occurs only once every few years, and other than one other transit in 2019, we won't have a chance to see Mercury pass over the Sun until 2039. While this one will be visible throughout North America, Mexico, Central America, South America, and parts of Europe, Asia, and Africa, those on the East Coast of the U.S. and east side of South America will get the best views. 

(Photo by SSPL/Getty Images)

May 21 - Blue Moon

The the third of four full moons in this season, the May 21 full moon is known as a blue moon. This rare calendar event only happens once every few years, giving rise to the term, “once in a blue moon.” There are normally only three full moons in each season of the year, but fourth "blue" moons pop up every 2.7 years on average. Unfortunately, they are not actually blue. 

(Photo credit should read ROBERT ATANASOVSKI/AFP/Getty Images)

May 22 - Mars at Opposition

If you want to snap a picture of Mars, this is your best chance in 2016 (unless you happen to be a robot on Mars). The red planet will be at its closest point to Earth and its face will be fully illuminated by the Sun. A great time to photograph the planet, it's also a great time to capture some of the details on the surface with a medium-sized telescope.

(Photo by: Universal History Archive/UIG via Getty Images)

June 3 - Saturn at Opposition

Mere days after Mars comes in for its close up, Saturn swings on by too. The ringed planet will be brighter than any other time of the year on the 3rd -- and you'll be able to see not only its famed rings, but also a handful of bright moons as well if you pick up a telescope.  

(Photo by: Universal History Archive/UIG via Getty Images)

June 20 - June Solstice

The longest day and official start of summer in the Northern Hemipshere brings the shortest day in the Southern Hemisphere. It's another great chance to visit Stonehenge (you definitely won't be alone) or if you're the type of person who never wants the day to end, head up to somewhere like Anchorage, Alaska, where the day will last a full 22 hours. 

(Photo credit should read DESIREE MARTIN/AFP/Getty Images)

July 4 - Juno at Jupiter

Hello Jupiter! NASA's Juno spacecraft is on pace to arrive at Jupiter after a five year journey on July 4, 2016. Launched on August 5, 2011, Juno will be inserted into a polar orbit around the giant planet to begin studying Jupiter’s atmosphere and magnetic field until October 2017, when it will go out in a blaze of glory as it crashes onto the planet's surface.

(Photo by Bill Ingalls/NASA via Getty Images)

July 28, 29 - Delta Aquarids Meteor Shower

Another great meteor shower that focuses on the constellation Aquarius, this one runs annually from July 12 to August 23 and peaks the night of July 28. The visible moon will block fainter meteors more than a few good ones should shine through. 

(Photo via dtana/Flickr)

August 12, 13 - Perseids Meteor Shower

The Perseids is consistently one of the best meteor showers for those who like to count "shooting stars" with up to 60 meteors per hour at its peak. This year's conditions are especially good for anyone willing to stay up late, since the waxing moon should set shortly after midnight. The meteors are produced by comet Swift-Tuttle, lasting from July 17 to August 24 and peaking on the night of August 12. Look to the constellation of Perseus for the best sight. 

(Photo credit should read SERGEY BALAY/AFP/Getty Images)

September 3 - Neptune at Opposition

If you have access to a telescope and want to catch a view of the blue giant planet, this is your best shot. Neptune will come closest to the Earth than any other time of the year, but at a distance of about 2.8 billion (on average) miles, you'll still need to find a powerful telescope to see it.

(Photo via NASA)

September 16 - Penumbral Lunar Eclipse

The Moon will only darken slightly during this eclipse, since it's passing through the Earth's penumbra and not full shadow, but it'll seen visible in most of eastern Europe, eastern Africa, Asia, and western Australia.

(NASA Map and Eclipse Information)

 (Photo by SSPL/Getty Images)

September 22 - September Equinox

The first day of fall in the Northern Hemisphere and the first day of spring in the Southern Hemisphere brings nearly equal amounts of day and night around the world. For those who can visit China, you'll have a chance to celebrate the Mid-Autumn Festival, also known as the Moon Festival, and eat moon cakes. 

(Photo by Rob Stothard/Getty Images)

October 7 - Draconids Meteor Shower

The Draconids is an unusual shower in that the best viewing is in the early evening, and it only produces 10 or so meteors an hour at its peak. Meteors will come from the constellation Draco, and you'll want to find the darkest conditions possible to watch this one. 

(Photo via Pete Hunt/Flickr)

October 16 - Full Moon, Supermoon

October's full Moon will also be the first of supermoons for 2016. Supermoons occur when the Moon is both full and closest to the Earth, meaning it appears slightly larger and brighter than usual for many.

(Photo by Matt Cardy/Getty Images)

October 21, 22 - Orionids Meteor Shower

Halley's Comet left behind dust that creates the Orionids shower each year. This average shower has around 20 meteors per hour at its peak, which happens peaks this year on October 21 at night. Best viewing will be from a dark location after midnight, and look for meteors to come from the constellation Orion.

(Photo via NASA)

November 4, 5 - Taurids Meteor Shower

Although it's a relatively light meteor shower, the Taurids are unique in that they consists of two separate streams: one that comes from dust of Asteroid 2004 TG10 and another fromdebris left behind by Comet 2P Encke. The shower has an extremely long run -- from September 7 to December 10 -- and it will peak on the the night of November 4. Keep your eye on Taurus and wait for the Moon to set for the best sights. 

(Photo via steffo photography/Flickr)

December 13, 14 - Geminids Meteor Shower

If you check out only one meteor shower this year, it should be the Geminids. It typically produces up to 120 multicolored meteors per hour at its peak. The shower will last from December 7 to 17, and peak on the night of the 13th. Best viewing will be from a dark location after midnight, looking to the constellation Gemini.
(Photo via TierraLady/Flickr)

December 21 - December Solstice

This is the first day of winter and longest night of the year in the Northern Hemisphere and the first day of summer and longest day of the year in the Southern Hemisphere.

(Photo by Matt Cardy/Getty Images)

December 21, 22 - Ursids Meteor Shower

This meteor shower will radiate from Ursa Minor -- also known as the little bear -- and produce about 5-10 meteors per hour. 

(Photo via Shutterstock)


The tiny planet, slightly larger than Earth's moon, will start off as a small black dot on the edge of the sun at 7:12 a.m. Eastern (1112 GMT). Traveling 30 miles (48 km) a second, Mercury will take 7.5 hours to cross the face of the sun, which is about 864,300 miles (1.39 million km) in diameter, or about 109 times larger than Earth.

"Unlike sunspots, which have irregular shapes and grayish borders, Mercury's silhouette will be black and precisely round," Sky and Telescope said in a press release.

The event will come into view in the western United States after dawn, with the transit already in progress. The show will end at sunset in parts of Europe, Africa and most of Asia.

NASA Television, available on the Internet, will broadcast live video and images from the orbiting Solar Dynamics Observatory and other telescopes. The show includes informal discussions with NASA scientists, who will answer questions submitted via Twitter using the hashtag #AskNASA.

Other options for armchair astronomers include:

- plans a live webcast with expert commentary, beginning at 7 a.m. EDT/1100 GMT.

-, which offers live telescope viewing via the Internet, will host a show on its website featuring images of Mercury taken by observatories around the globe.

- Europe's Virtual Telescope, another robotic telescope network, will webcast the transit at

Scientists will take advantage of Mercury's transit for a variety of science projects, including refining techniques to look for planets beyond the solar system.

"When a planet crosses in front of the sun, it causes the sun's brightness to dim. Scientists can measure similar brightness dips from other stars to find planets orbiting them," NASA said.

Mercury's last transit was in 2006 and the planet will pass between the sun and Earth again in 2019. After that, the next opportunity to witness the event will not come until 2032.

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