The planets will be aligned on Nov. 11 for a rare astronomical event known as the transit of Mercury, and skywatching fans are sure to see it even if the skies are cloudy, thanks to this little thing called the internet.
For folks in Western Washington, watching the action online will be the best bet when the tiny black dot of Mercury’s disk crosses the sun. Mercury will make its first contact at 4:35 a.m. PT, when the skies will still be dark in Seattle. It’ll be another two and a half hours before the sun creeps over the Cascades. By that time, the transit will be almost half-done.
A mission to the planet Mercury got off to a flashy start with tonight’s launch of an Ariane 5 heavy-lift rocket, but there’s a long way to go before the double-barreled BepiColombo probe gets to its destination.
Liftoff from the European Arianespace launch complex in Kourou, French Guiana, came off flawlessly at 10:45 p.m. (6:45 p.m. ET). The $1.5 billion mission, named after the late Italian astrophysicist Giuseppe “Bepi” Colombo, is a joint project of the European Space Agency and the Japan Aerospace Exploration Agency, or JAXA.
Over the course of seven years, the spacecraft will trace a complex path with an Earth flyby in 2020, two Venus flybys and six Mercury flybys. All those close encounters are carefully designed to slow down BepiColombo’s speed enough to put it into a stable orbit around Mercury in 2025. (It was Colombo who suggested such a series of gravity-assist maneuvers could work for a Mercury mission.)
For the first time in a decade, we Earthlings can watch the planet Mercury’s black speck pass across the sun on Monday – even in Seattle, where seeing the sun can be an iffy proposition. Just make sure you see it safely.
“This is one of the very rare opportunities to see the parts of the solar system in motion,” said Stephanie Anderson, president of the Seattle Astronomical Society. “It doesn’t happen very often, so when you get an opportunity, take it.”
The event begins at 4:12 a.m. PT, when the edge of our solar system’s closest-in planet appears to touch the sun’s disk. That’s before dawn for West Coasters, so Seattleites will have to wait until sunrise at 5:40 a.m., when the transit is in progress.
Anderson and other skywatchers plan to be ready at Snoqualmie Point Park, just off Interstate 90 at Exit 27, for a viewing party sponsored by the astronomical society. Members will set up telescopes with solar-safe filter for a look-see. Some of the telescopes will be equipped with hydrogen-alpha filters that highlight solar prominences.
The forecast for Monday morning calls for partly cloudy skies over Seattle, but if the weather is favorable, the party could go on until Mercury completes its transit at 11:42 a.m. PT. Keep an eye on the Seattle Astronomical Society’s website for updates.