Catching the Mercury transit from Seattle

The weather gods smiled on West Seattle Monday and provided relatively clear skies that allowed us to catch much of the first transit of Mercury across the disk of the Sun in ten years. The event served as a reminder of how hyper-local the weather can be, as many other locations around the area did not fare so well.

Viewing the Mercury transit.

After about 8:30 a.m. May 9 the clouds parted and we had excellent viewing of the transit of Mercury. Spencer (left) and Ryan take a peek through Spencer’s homemade Dobsonian. Photo: Greg Scheiderer.

We thought we may have jinxed the weather when we wrote on Sunday in our weekly calendar post that, “(I)t’s pretty unlikely that we’ll see the transit constantly from sun-up to finish, but also looks pretty unlikely that we’ll get skunked.” I arrived with telescope in hand at Seacrest Marina Park just before 6 a.m. on Monday, and the clouds were solid. I was soon joined by Ryan “Tortuga” Carpenter and a young man named Spencer who brought his home-made Dobsonian telescope to the party. For a while we just watched the clouds roll by.

It was well after 7 a.m. before we got our first glimpse of the Sun, and Mercury in transit—a fleeting look that lasted less than a minute. For the next hour or so we had several similar quick peeks at the ttransit when the Sun found a hole in the clouds.

We finally got some longer looks after 8 a.m., long enough to actually snap photographs of the transit. Then, right about 8:30, we suddenly had clear, blue skies. We had a few interruptions from clouds after that, but these were brief and we had close to constant viewing of the transit until it ended around 11:40 a.m.

Other areas didn’t have so much luck, especially those sites east of the city. The Seattle Astronomical Society had a transit-viewing event scheduled from one of its preferred observing sites at Snoqualmie Point Park, but had already cancelled it by Sunday night because of inclement weather in the forecast. One member went there anyway and reported only brief views of the transit. Others reporting to the society’s Google forum, fittingly titled “Through the Clouds,” also noted limited success from Kent, Ellensburg, and Bellevue. The Green Lake neighborhood had decent weather and observers there reported more lengthy looks at the transit.

Transit of Mercury

If you click on this photo to see the larger version you can see Mercury just to the left of the center of the disk of the Sun, and a sunspot cluster to the right. Taken with a Canon PowerShot A530 through an 8-inch Dob at 48 power. Photo by Greg Scheiderer.

Our trio in West Seattle tried to do a little science, or at least figuring, at the end of the transit. We each clocked the time between third and fourth contact of the transit. Interestingly enough, our observations varied by about 15 seconds. Parallax doesn’t explain that; our telescopes were all set up within about 10 feet of each other! I would guess that the variation could be explained by differences in visual acuity, quality of telescope optics, and ability to find the start/stop button on the smartphone stopwatch. Carpenter did the math and said we were in the ballpark for determining the size of Mercury based on the length of time between the two contacts.

Mostly we just had fun seeing this rare celestial event, and sharing it with quite a number of interested passers-by. I chose the site because a lot of people are typically there, from those catching the West Seattle Water Taxi into the city to those just strolling in the park. Great weather was an unexpected bonus.

While there are only, on average, 13 transits of Mercury in a century, our next one is relatively soon: November 11, 2019. After that we’ll have to wait 13 years, until 2032, for another.


Astro Biz: Portland Mercury

Portland MercuryMany businesses, products, and places have names rooted in space and astronomy. We’re featuring one every Tuesday on Seattle Astronomy.

This week’s Astro Biz is the Portland Mercury, an alternative news weekly that is a cousin to The Stranger of Seattle. Both are published by Index Newspapers LLC, based in Seattle.

Mercury has been a popular name for newspapers over the years, given that the Roman god Mercury is the patron god of communication, what with the great speed on winged feet. Mercury also has a variety of other bailiwicks.

You may have guessed that we chose the Portland Mercury this week because of yesterday’s transit of the planet Mercury across the face of the Sun (and also because we shot the photo above during a recent trip to the Rose City.) We had clear skies for much of the transit and viewed it successfully from Seacrest Marina Park in West Seattle.

More info:

Do you have a favorite Astro Biz? Send us a photo and a brief description, and you may be featured in a future Astro Biz!

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Transit of Mercury highlight of the week; maybe the year

The most anticipated observing event of the year happens Monday morning, May 9, as Mercury will transit across the face of the Sun. The transit begins at 4:13 a.m. Pacific Daylight Time, so it will be under way when the Sun rises in Seattle.

NASA illustration.

NASA illustration.

The weather gods are taunting Seattle astronomers, as usual. After a pretty good run of mostly clear weather, we awoke to rain on Mother’s Day morning. The forecast is for mostly cloudy cloudy skies around sunrise Monday, turning to sunny by noon, when the transit will be over. So, it’s pretty unlikely that we’ll see the transit constantly from sun-up to finish, but also looks pretty unlikely that we’ll get skunked.

There are several transit-observing events that we know about. Seattle Astronomy will be down at Seacrest Park near the West Seattle Water Taxi dock with a telescope; join us and have a look! The Seattle Astronomical Society will hold an observing event at Snoqualmie Point Park near the town of Snoqualmie. (UPDATE: The SAS event has been cancelled due to inclement weather.) There will be transit viewing and programming at the Pierce College Science Dome in Lakewood. Rose City Astronomers and the Oregon Museum of Science and Industry will be observing the transit from the OMSI site in Portland. Check the links for details.

A couple of things to keep in mind about the transit. First, don’t ever, ever, ever look at the Sun without proper protection. Regular sunglasses won’t do the trick. You need special eclipse glasses. Second, Mercury is so small that you will need magnification to see it, and that means a telescope also equipped with the proper solar filters. Be safe out there!

Read our preview article about the Mercury transit.

AstronoMay continues

Pacific Science CenterAstronoMay continues at the Pacific Science Center this week. There will be two interesting lectures on Saturday, May 14. At 10 a.m. Elena Amador, a graduate student at the University of Washington, will talk about the search for water on Mars. Then at 2:30 p.m. Dr. Sandeep Singh, a planetary scientist from the Bear Fight Institute in Winthrop, will speak about Saturn’s largest moon Titan. Singh has worked on NASA’s Rosetta, Cassini, and DAWN missions.

Volunteers from the Seattle Astronomical Society will be on hand much of the day Saturday with solar telescopes for observing the Sun, and the center is offering planetarium shows and other astronomy-related programming throughout the week. Check their calendar for details.

PacSci Podcast about AstronoMay:

Club events

Tacoma Astronomical SocietyThe Tacoma Astronomical Society will host one of its public nights beginning at 9 p.m. this Saturday, May 14 on the Fort Steilacoom campus of Pierce College. The program will be about black holes, and there will be observing if the weather permits.

BPAAThe Battle Point Astronomical Association has several events on Saturday, May 14 at its Edwin Ritchie Observatory in Battle Point Park on Bainbridge Island. At their BPAstro Kids shows at 5 p.m. and 6 p.m. youngsters will build their own planets and check them for life. Following at 8 p.m. astronomer Steve Ruhl will examine exoplanets: How we see them, what they tell us about our solar system, and how we might know if there other habitable worlds out there.

Check out our recent article and podcast about BPastro Kids:

Up in the sky

The Mercury transit is the big astronomical event of the week. The Sky This Week from Astronomy magazine and This Week’s Sky at a Glance from Sky & Telescope have other observing highlights for the week.


Southern Illinois: eclipse crossroads of America

Carbondale, Illinois is beating the odds. It’s said that, on average, a total solar eclipse can be seen from the same spot on Earth only once every 375 years. Carbondale will be getting two total solar eclipses in the next eight years, as the paths of the August 2017 and April 2024 events cross in southern Illinois. There’s little wonder that the area is billing itself as the “Eclipse Crossroads of America.”

Eclipse Crossroads of America“It’s a wonderful outreach opportunity,” said Bob Baer in something of an understatement. Baer heads up public astronomy programs at Southern Illinois University in Carbondale and is co-chair of its Solar Eclipse Steering Committee, which has been planning for the 2017 eclipse for almost two years already. Complicating their planning somewhat is the fact that the day of the 2017 eclipse, August 21, is also the first day of classes for fall semester at the university. (We hope all of the students will cut their 1 p.m. classes to see the eclipse!) They’ll have students moving in, parents still around, and as many as 50,000 extra eclipse chasers in the area.

“We’re planning on having events through the weekend and on Monday,” the day of the eclipse, Baer said, noting they’re shooting for edu-tainment—some science as well as entertainment. SIU athletic facilities will be key. They can accommodate a lot of people, and the university can link the big screens in their football stadium and basketball arena together. Baer said they’re working with NASA and their local PBS station, WSIU, to offer eclipse programming that day and to show coverage from other places along the eclipse path.

AASI logoThe local astronomy club, the Astronomical Association of Southern Illinois, is a relatively modest operation with only about 30 members, but president Harry Treece said they’ll be doing their part.

“We are going to be manning one of the stations at a state park near here called Giant City, hosting an area there for different astronomy clubs and people like that who can come in,” he said. Treece said he’s glad that the university is also reserving some space that won’t be so public for more serious astronomical observers.

“It will be a place for like-minded people who can set up their equipment, and there won’t be general public, lots of people, little kids running around knocking scopes over, and things like that,” he said.

Baer and Treece say there’s a lot to consider.

“Most of Southern Illinois is going to see the eclipse, so we’ve been holding workshops for about the last year,” Baer said. “These have been aimed toward communities, businesses, emergency personnel, and the cities to give them basic information on the eclpise and help them get started on planning.”

Treece added that they’ve urged cellular telephone companies to bring in temporary towers to handle the anticipated surge in traffic. The SIU athletics department is securing generators to make sure they have enough power to support larger crowds. Planners have gone as far as Chicago in search of enough porta-potties.

Accommodations and weather

Can the area handle so many visitors? Baer thinks so. He notes that there are about 3,000 hotel rooms within an hour or so of Carbondale, and most hotels in the area don’t take reservations for more than a year out. They’ll probably be snapped up in a hurry starting August 21 of this year. In addition, there are some 300,000 acres of public land in the region with plenty of camping in state parks and national forests.

As for the weather, it’s typically very hot and humid in August in Carbondale. It’s one of the reasons they’re making indoor venues available, so people can duck out of the heat. Baer said they often have morning clouds that clear by afternoon, and that it’s rare to have complete overcast. So they’re hopeful for good eclipse viewing in town.

Why Carbondale?

“Carbondale is going to be having a big, carnival-like atmosphere for the whole thing,” Treece said. “It’s a beautiful part of the country, there’s a lot to do a couple of days before or after.”

“We have a large number of wineries in southern Illinois,” as well as craft breweries, Baer said. “The center line of totality goes right through our two wine trails. It’s a great opportunity for a lot of local businesses and their venues to host things during the eclipse and leading up to it.”

“If people want to come to the area ahead of time, there’s plenty to do,” Baer added, noting that it’s easy to get around, so people can come early and explore before deciding where to go to watch the eclipse. He described an area along Route 3 headed to St. Louis, which is about 80 miles northwest of Carbondale as the crow flies.

“There are these beautiful limestone bluffs that overlook the Mississippi River,” Baer said. “Those areas down there, the bottom grounds and those bluffs, are excellent places to get and be in a flat area where you can see that 360-degree sunset effect that you get during an eclipse.” He said you might find an elevated spot from which you could see the Moon’s shadow sweeping across the Earth as it approaches from the west.

Eclipse science

Bob Baer

Bob Baer. SIU photo.

With all of this going on, Baer is going to be doing some real science during the eclipse, too. He’s part of Citizen CATE (Citizen Continental America Telescopic Eclipse Experiment), a project that hopes to observe and shoot video of the corona of the Sun from 60 locations across the country during the eclipse.

“We’re looking at the evolution of the corona,” he said. “We can image the corona directly, and we can start to learn about how the magnetic fields of the Sun affect that solar corona.”

“We’re hoping to make a 90-minute movie from that so we can see the corona as it evolves,” he added.

Baer went to Indonesia for the total solar eclipse there in March, something of a trial run for Citizen CATE. It was his first total solar eclipse.

“It’s a bit of a life-changing experience,” he said, even though they knew what to expect. “Until you’ve experienced it, it really doesn’t sink in.”

We expect that millions of people will experience it for the first time in August 2017.

Our podcast with Baer and Treece:


Astro Biz: Blue Mercury

Blue Mercury PortlandMany businesses, products, and places have names rooted in space and astronomy. We’re featuring one every Tuesday on Seattle Astronomy.

This week’s Astro Biz is Blue Mercury. The company has a chain of makeup and skincare stores and spas around the country. There’s one at University Village in Seattle, but we first spotted Blue Mercury on a recent visit to Portland, Oregon.

We selected Blue Mercury this week because we’re getting pumped for Monday’s transit of Mercury. There’s some reason to be optimistic; a current forecast of “partly cloudy” for the day makes us think we’ll have a good shot at a glimpse of the transit. We’ll be watching the forecast over the coming days.

More info:

Do you have a favorite Astro Biz? Send us a photo and a brief description, and you may be featured in a future Astro Biz!

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AstronoMay kicks off at PacSci

Pacific Science CenterWhy settle for one astronomy day when you can have AstronoMay? Astronomy Day is May 14, but the Pacific Science Center has the whole month packed with astronomy activities. The first is coming up at 5:30 p.m. Thursday, May 5 in the center’s Willard Smith Planetarium, which will hook up with the Adler Planetarium and others around the country for an interactive, networked lecture, “From The Big Bang To The Multiverse And Beyond.” The talk will be given by Dr. Michael Turner of the University of Chicago, a noted cosmologist credited with coining the term dark energy. Turner will delve into what we know and also tackle some of the mysteries and puzzles of cosmology today.

Other lectures planned for AstronoMay:

  • Elena Amador, a UW graduate student in Earth and Space Sciences, presents, “Search for Water on Mars” May 14 at 10 a.m.
  • Dr. Sandeep Singh, planetary scientist at the Bear Fight Institute, presents “Saturn’s Hazy Moon, Titan” May 14 at 2:30 p.m.
  • Dr. Will Grundy of Lowell Observatory presents “Pluto & Charon Up-Close” May 22 at 2:15 p.m.

The lectures are free with admission to the Pacific Science Center, but tickets are required and available online.

On Saturdays during May, and on Sunday, May 22, volunteers from the Seattle Astronomical Society will be set up on the courtyard of the center with solar telescopes for safe viewing of the Sun. All month long there will be exhibits and hands-on activities about space and astronomy, and planetarium presentations (our calendar has the schedule) and IMAX movies, including A Beautiful Planet 3D.

AstronoMay website and calendar.

Club news

Tacoma Astronomical SocietyArea astronomy clubs are busy this week. The Tacoma Astronomical Society will hold its monthly meeting at 7:30 p.m. Tuesday, May 3 in room 175 of Thompson Hall at the University of Puget Sound. There will be a presentation by Michael Laine, president of the Liftport Group, which is drawing up plans for a lunar elevator. The club will hold one of its free public nights at 9 p.m. Saturday, May 7 at the Fort Steilacoom campus of Pierce College. The TAS student group will make a presentation about the solar system. Observing will happen if weather permits.

Spokane Astronomical SocietyThe Spokane Astronomical Society will hold its monthly meeting at 7:30 p.m. Friday, May 6 at the planetarium at Spokane Falls Community College. Stefanie Milam, a project scientist with the NASA Goddard Space Flight Center, will give a presentation on either the James Webb Space Telescope or recent discoveries of sugar and ethanol in comets. They note the latter represents all of the makings for a wild star party.

Olympic Astronomical Society will hold its 12th annual spring Camp Delaney Star Party May 4-8 out at Sun Lakes State Park near Coulee City in Eastern Washington. Club members already on site recommend industrial strength bug protection as the mosquitos are out in force. Note the preregistration was required for the event.

Supernova impostor

Brianna Binder

Breanna Binder. Photo: Greg Scheiderer.

Dr. Breanna Binder of the University of Washington will give an astronomy colloquium at 4 p.m. Thursday, May 5 in the Physics/Astronomy Auditorium on the UW campus in Seattle. Binder will talk about supernova 2010da, which is not really a supernova, but an interesting object with a high-luminosity, variable X-ray emission. The X-ray emission is consistent with accretion onto a neutron star, making SN 2010da both a supernova impostor and likely high mass X-ray binary. Binder gave a talk about x-ray binary systems last August at the Seattle Astronomical Society’s monthly meeting.

Space Day at Museum of Flight

moflogoThursday is not only Cinco de Mayo, it is Space Day at the Museum of Flight. It’s part of the Museum’s free first Thursday from 5 p.m. until 9 p.m. Local astronomy clubs will be on hand with information, and telescopes for observing if weather permits.

Open House at TJO

There will be an open house at the University of Washington’s Theodor Jacobsen Observatory at 9 p.m. Wednesday, May 4. As of this writing the schedule for the events talks by undergraduate students had not been published online. Volunteers from the Seattle Astronomical Society will be on hand to offer observatory tours, and perhaps a peek through its vintage six-inch 1892 Warner and Swasey telescope with Brashear objective.

Up in the sky

The Eta Aquarid meteor shower peaks this week. Learn about the shower and other observing highlights for the week from This Week’s Sky at a Glance by Sky & Telescope magazine or The Sky This Week from Astronomy.


Gravitational wave discovery ushers in new era in astronomy

“This is beginning a new era in astronomy,” said Ethan Siegel about the publication in February of a paper announcing that scientists had detected gravitational waves. Siegel has taught physics and astronomy at Lewis & Clark College and the University of Portland in Portland, Oregon. He is creator of the science blog Starts With a Bang, and is the author of Beyond the Galaxy: How Humanity Looked Beyond Our Milky Way and Discovered the Entire Universe (World Scientific, 2015). Siegel gave a talk at this month’s meeting of the Rose City Astronomers in Portland about what he calls the discovery of a lifetime.

Dr. Ethan Siegel, creator of the "Starts With a Bang" blog, gave a talk about the discovery of gravitational waves to the Rose City Astronomers April 18. Photo: Greg Scheiderer.

Dr. Ethan Siegel, creator of the “Starts With a Bang” blog, gave a talk about the discovery of gravitational waves to the Rose City Astronomers April 18. Photo: Greg Scheiderer.

“This was something, when it was first proposed, that was really taken to be a preposterous consequence of a theory and something that we never really thought we were going to be able to test,” Siegel said. “We have gone in 101 years from pure theory to concrete, direct detection of gravitational waves.”

Einstein’s theory of relativity states that mass and energy bend spacetime, and that’s why objects orbit each other. Relativity explained anomalies in the orbits of planets in our solar system, but Siegel said there is an “extra weird” effect because the orbits decay.

“Another consequence of Einstien’s relativity is that as things spiral in, and it takes a long time to do, but as they do they emit a special type of radiation; they emit radiation that goes through the fabric of space itself,” Siegel said. “This is gravitational radiation.”

It takes way too long for that to happen here in the solar system. For Earth’s orbit to decay completely and merge with the Sun would take 10150 years, according to Siegel. He said we’ll have to look elsewhere to see the effects happen on human-length time scales.

“You need to find heavy masses; heavier mass in relativity means a stronger effect,” Siegel said. “You need them to have small distances, where small distance is a few kilometers, not a few million miles. And you need them to orbit at fast speeds, where fast is kind of close to the speed of light.”

Luckily these conditions exist. Black holes, neutron stars, and pulsars can do the trick; the gravitational waves detected by the Laser Interferometer Gravitational-Wave Observatory (LIGO) last fall were generated by merging black holes. One of those black holes started out at 36 solar masses and the other at 29. After the merger they weighed in at 62 solar masses. That’s simple arithmetic: 36+29=65; what happened to the other three solar masses? Siegel said, oddly enough, this was a prediction by Einstein as well. It’s the flip side of e=mc2.

“When these two black holes merged, three solar masses, about five percent of the total mass, was converted into pure energy,” he said. “That energy is the gravitational radiation and is why we here on Earth were able to detect this huge event of two black holes merging from over a billion light years away.”

Siegel is amazed that we were able to figure the mass, spin rate, merging speed, mass loss and other characteristics of these distant objects.

“We learned all of this information from one 20-millisecond signal that moved two laser arms by less than 10-18 meters,” he marveled. “What I’d say we have now is a whole new way to discover our universe.”

Siegel, an entertaining and informative speaker, is scheduled to give another talk at the October 2016 meeting of Rose City Astronomers. He will discuss his book Beyond the Galaxy.

That way is improving rapidly. The LIGO detectors at Hanford, Washington, and Livingston, Louisiana, are being tweaked to even greater sensitivity. New detectors are planned for Italy, Japan, and India. Siegel said the ultimate would be to build three huge LIGO detectors in space, forming an equilateral triangle in Earth’s orbit and having detector arms hundreds of millions of kilometers long.

“If you do that, you can not only watch things merge with supermassive black holes, you can find mergers of ultramassive black holes,” Siegel said. We might even be able to spot gravitational waves from cosmic inflation within the light of the cosmic microwave background. Siegel said if that happens, it would prove that gravity is a quantum force.

“There’s no way to make these fluctuations unless gravity is inherently a quantum force,” he explained. “The process that makes these fluctuations is a quantum process.”

Siegel said it’s a thrilling time to be involved in astronomy.

“This is the first time we’ve seen something astronomical without using a telescope or light of any type,” he said. “This is the dawn of astronomy beyond light-gathering telescopes.”