Kirkwood Observatory at IU Bloomington to offer public viewing, live stream of Mercury transit

  • May 4, 2016


BLOOMINGTON, Ind. -- The Department of Astronomy in the Indiana University Bloomington College of Arts and Sciences will provide a live stream from Kirkwood Observatory of the upcoming transit of Mercury on May 9.

The transit of Mercury is a celestial event in which the planet closet to our solar system's sun passes between the Earth and Sun, casting a silhouette across the star's surface.

The observatory will also be open for visitors who wish to view the transit in person from 11 a.m. to 3 p.m. Kirkwood Observatory is between Fourth Street and Kirkwood Avenue behind Bryan Hall on the IU Bloomington campus.

To access the live stream starting at 11 a.m., visit the Department of Astronomy's website.

The live stream and open house are weather permitting. Both are free and open to the public.

"We're excited to welcome the public to our observatory on campus and online to experience in this beautiful and educational event," said Catherine A. Pilachowski, the Daniel Kirkwood Chair in the IU Bloomington Department of Astronomy. "This is the first opportunity to experience Mercury's transit across the Sun in nearly a decade, and we're eager to help everyone with a love of space get a front-row seat to this rare celestial dance."

In Indiana, Mercury's transit will begin after sunrise at 7:13 a.m. and end at 2:41 p.m., with the moment of greatest transit occurring around 10:58 a.m.

The transit begins before sunrise for observers in western North America and ends after sunset for Eastern Europe, Asia and most of Africa. Regions where the entire transit is visible include eastern North and South America, the Atlantic Ocean and Western Europe.

It will not be visible in eastern Asia, Japan, Indonesia, Australia and New Zealand.

The safest and easiest way to view the transit is online, or in person with the assistance of IU's astronomy faculty and students. The silhouette of Mercury, which is 3,000 miles wide, will be too small to see with the naked eye -- a mere 1/158th of the Sun's apparent diameter.

The transit should only be observed using an instrument with an approved full-aperture solar filter to avoid serious eye damage. A safe alternative is to project the Sun's image through a telescope or binoculars onto a white card. Never look at the sun without proper protection.

The last time the planet Mercury passed between the Earth and Sun was Nov. 8, 2006. The next transit of Mercury will not take place until Nov. 11, 2019, after which it will take place only 10 more times this century.

In addition to the special event May 9, Kirkwood Observatory is open to stargazers from 10 to 11:30 p.m. every Wednesday.

A special open night will be held Sunday, May 15, in celebration of the observatory's 115th anniversary.

Updates on weather conditions and open night viewings at the observatory are available on the Department of Astronomy's observatory website or on Twitter, @iuastro.

Transit of Mercury

Mercury casts a small shadow as the planet passes between the Earth and the Sun. | Photo by UH Mees Solar Observatory on Haleakala

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2006 transit of Mercury

Community members line up to watch the sky on the IU Bloomington campus during the last transit of Mercury in 2006. | Photo by Indiana University

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