Mercury Transit 2019: How to Watch the Rare Event Live Online

When Mercury passes in front of the sun today (Nov. 11), skywatchers will need to have the right equipment to see it safely. But if you don't have the right astronomy gear handy, you can watch the transit live online.

Observatories around the world will be broadcasting live views of the sun on Monday, when Mercury will cross in front of the sun from our perspective here on Earth. Mercury won't do this again until 2032, so you don't want to miss it! 

Mercury will begin to creep onto the sun's disk at 7:35 a.m. EST (1235 GMT), and it will take about 5 hour and 28 minutes to make its way across, with the transit ending at 1:04 p.m. EST (1804 GMT). You can watch the entire transit live here on We have rounded up a list of several different webcasts you can choose from, and you can find those below. 


The online observatory Slooh will host a live webcast of the entire Mercury transit, and the show will feature close-up views of the sun from Slooh's flagship observatory at the Institute of Astrophysics of the Canary Islands and its partner observatories in Europe, the U.S., South America and Sharjah in the United Arab Emirates. 

Slooh astronomer Paul Cox will provide commentary during the transit, and he will be joined by other "astronomical experts who will discuss Mercury, the sun, and planetary transits," Slooh officials said in a statement. "The team will also discuss the importance of planetary transits in history and why major expeditions to observe them were organized at great expense during the 1700s."

Slooh's webcast begins at 7:30 a.m. EST (1230 GMT), about 5 minutes before the start of Mercury's transit, and it will end at about 5 minutes after the transit ends 1:10 p.m. EST (1810 GMT). You can watch it live at (with a free subscription), or watch it on YouTube.

In the video above, you can see the views that Slooh recorded during the last Mercury transit on May 9, 2016.

The Virtual Telescope Project

The Virtual Telescope Project, an online observatory based in Italy, will also stream live telescope views of the Mercury transit. Astrophysicist Gianluca Masi, founder of the Virtual Telescope Project, will provide live commentary during the webcast. 

That webcast will also begin at 7:30 a.m. EST (1230 GMT), and you can watch it on Masi's YouTube channel. Masi created a digital simulation of the transit, which you can watch here in the window above.

Time And Date

Time and Date, one of's go-to websites for timetables and visualizations for astronomical events, is hosting its own webcast of the Mercury transit. "Weather permitting, we bring you spectacular live telescope footage of the transit of Mercury," the webcast's description says. 

That webcast will be available on YouTube beginning at 7:30 a.m. EST (1230 GMT), and you can find tons of useful information about the transit — including visibility maps, simulations and timetables — at

Griffith Observatory

The Griffith Observatory in Los Angeles, which often hosts public skywatching events, will be streaming live views of the transit at 9:15 a.m. EST (6:15 a.m. local time; 1415 GMT)

Because the observatory is closed on Mondays, it will not be hosting a special event for the transit. You can watch the webcast live here and on YouTube.

Solar Dynamics Observatory

NASA TV has not yet announced a webcast for the Mercury transit, but the agency's Solar Dynamics Observatory (SDO) will be uploading "almost-live" imagery from its unique vantage point in space. 

You can see the latest SDO images of the transit at

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Hanneke Weitering
Contributing expert

Hanneke Weitering is a multimedia journalist in the Pacific Northwest reporting on the future of aviation at and Aviation International News and was previously the Editor for Spaceflight and Astronomy news here at As an editor with over 10 years of experience in science journalism she has previously written for Scholastic Classroom Magazines, MedPage Today and The Joint Institute for Computational Sciences at Oak Ridge National Laboratory. After studying physics at the University of Tennessee in her hometown of Knoxville, she earned her graduate degree in Science, Health and Environmental Reporting (SHERP) from New York University. Hanneke joined the team in 2016 as a staff writer and producer, covering topics including spaceflight and astronomy. She currently lives in Seattle, home of the Space Needle, with her cat and two snakes. In her spare time, Hanneke enjoys exploring the Rocky Mountains, basking in nature and looking for dark skies to gaze at the cosmos. 

  • rod
    Some good reports for the Mercury transit coming on Monday by This celestial event provides an opportunity to teach basic astronomy too - the heliocentric solar system and astronomical unit. I offer this note. There are citizen science groups observing this Mercury transit to measure the solar parallax and using trigonometry - record the distance between Earth and the Sun, i.e. the astronomical unit (done in 2016 and also previous Venus transits in 2004 and 2012). The method using Venus and Mercury transits - recorded in astronomy since the 1700s. In the geocentric world of Claudius Ptolemy, Tycho Brahe, the great upheaval period with Galileo, telescopes did not exist or just beginning to be used. Only later after Galileo's days, telescopes were used to record and measure the solar parallax - showing the astronomical unit. Using Venus and Mercury transits was proposed in 1716 by Edmond Halley astronomer. Cassini and Richer used telescopes to measure the Mars parallax when Mars was at or near opposition in 1672. Tycho Brahe failed to measure the Mars parallax in the late 1500s because Mars distance from Earth, too far away for Tycho using unaided eye instruments to measure. Astronomers never understood just how far away until the Mars parallax was obtained using telescopes in 1672. Tycho Brahe wanted to measure the Mars parallax to show Mars was always farther away from Earth than the Sun - to refute Copernicus system. Copernicus showed at times, Mars would be closer to the Earth than the Sun using his heliocentric solar system but the real distances were unknown. Starting in 1672, astronomers began to understand the true size and dimension of the solar system and distances to the planets and the Sun. Previously, the geocentric firmament astronomy was always a small universe with the Sun much closer, perhaps 1200 earth radii vs. some 23455 earth radii today using that unit of measure. Claudius Ptolemy geocentric astronomy placed the sphere of fixed stars some 20,000 earth radii distance or 0.85 AU using the modern, astronomical unit, closer to Earth than the Sun in the modern heliocentric solar system. The depth of the Heavens... The Mercury transit provides opportunity to teach some of this critical, astronomical history to folks.