Local astronomy enthusiasts are offering a way to watch a rare celestial event Monday morning, May 9 as the planet Mercury “transits” the sun.
In astronomy terms, a transit is when a planet passes in front of the sun from the perspective of viewers on another planet, said Richard Just of the local astronomy group Whatcom Association of Celestial Observers.
Members of the club will have a half-dozen telescopes with solar filters on the lawn behind Bellingham Public Library, 210 Central Ave., from 7:30 a.m. to noon Monday.
The vast majority of the public has never looked through a telescope. People generally are impressed. It’s not a book or a magazine — it’s live.
Richard Just, Whatcom Association of Celestial Observers
“You’ll be able to see the sun, and any sunspots, and of course Mercury,” Just said. He’ll also have a projection telescope, and “I’ll be projecting on a white board so that several people can see the image at the same time.”
Instead of the star-like speck when Mercury is seen at night, the planet will appear as a black speck on the face of the sun, Just said. He emphasized that no one should look directly at the sun, unless it’s through a telescope’s solar filter or protective material such as welding glass.
A Mercury transit occurs about a dozen times or so every century — always in May or November. The last Mercury transit was in 2006, when the club offered a similar viewing opportunity.
From viewers on Earth, only Venus or Mercury can transit the sun, because they are the only planets whose orbits are inside Earth’s orbit in relation to the sun. On June 3, 2014, the Curiosity rover on Mars recorded Mercury transiting the sun, the first time a planetary transit has been observed from anywhere but Earth.
If clouds obscure the sun, Just said WACO members will have telescopes ready nonetheless, especially if sunbreaks are expected. The event will live-streamed at livestream.com/slooh/events/4520741 and that image will be projected on a screen in the library’s downstairs Lecture Room so the transit can be seen if the skies here are hopelessly cloudy.
Actual hours of the transit are 4:12 to 11:42 a.m. PDT.
“When the sun rises here, the transit will already be in progress,” Just said.
He said such public outreach programs are essential to developing a sense of wonder and curiosity about the environment, especially for children.
“The vast majority of the public has never looked through a telescope. People generally are impressed,” Just said. “It’s not a book or a magazine — it’s live.”
Several times during the summer, club members bring their telescopes to Boulevard Park for free public viewing sessions that offer a chance to see sunspots, craters on the moon, and Saturn’s rings. At those events, people who are considering buying a telescope can learn more about the different types of scopes and their advantages and disadvantages, Just said.
This year, telescopes will be available during first quarter moons from 6:30 to 10 p.m. Friday, May 13; Sunday, June 12; Monday, July 11; Wednesday, Aug. 10; and Friday, Sept. 9.
In addition, “star parties” are planned at Artist Point at 9 p.m. Saturday, July 9; Saturday, July 30; and Saturday, Aug. 27. While the Artist Point events are not officially for the public, curious viewers are welcome, Just said.
All viewing events and star parties are canceled if it’s cloudy. For more information, go to whatcomastronomy.org.