Tag Archives: Venus transit

Book review: Chasing Venus

Like many astronomy buffs, we’ve been putting a great deal of thought into deciding where we’ll go to try to see the total solar eclipse that will cross the United States next August 21. Seattle Astronomy has done 13 articles and a dozen podcasts on the topic. As with the 2012 Venus Transit or this year’s Mercury Transit, the key is figuring out where you’ll have the best odds for clear skies, and how to get to an alternate site if the clouds beat those odds on eclipse day.

With such thinking fresh in mind, I eagerly snapped up a copy of Andrea Wulf’s book Chasing Venus: The Race to Measure the Heavens (Vintage Books, 2012) when I spotted it in the astronomy section of Powell’s Books during a recent trip to Portland.

Chasing Venus is the story of the Venus transits of 1761 and 1769, and the international scientific effort to accurately observe the transit from many spots around the globe and use the solar parallax between those observations to calculate the distance between the Sun and the Earth, and thus get a true grasp for the size of the solar system.

The whole project was the brainchild of British astronomer Edmund Halley, who predicted the 1761 transit and wrote an essay in 1716 that urged scientists to spread out across the globe to make these vital observations. Halley was 60 at the time of the writing and would have to live to be 104 to see it himself; he died in 1742.

Scientists and nations answered the call with enthusiasm. This was, Wulf writes, “a century in which science was worshipped, and myth at last conquered by rational thought.” One is tempted to think that we’ve regressed in the intervening 247 years.

Technology was a challenge for the observers. They had good telescopes, but had to transport them long distances, in many cases, and set up observatories in remote locations. A bigger challenge was the actual timing of the transit. Clocks were not yet reliably accurate, and precise determination of longitude was still a challenge. The greater difficulty was actually getting to the observation sites. It was easy for those in the cities, but for the calculations to work observations had to be made from points on Earth as far apart as possible. Thus for every astronomer observing from the relative comfort of Paris, London, or Madrid another team was on a treacherous expedition to the far-flung corners of the world in an era when it took several months to get a letter from the American colonies to the European capitals. For the 1761 transit, the journey of French astronomer Jean-Baptiste Chappe d’Auteroche to Siberia was particularly harrowing, and those traveling by sea had to navigate not only the sea but the politics of the day, lest their efforts be defeated by heavy waters or hostile navies.

Imagine the mindset of astronomers who, at great expense, had to travel for months, and in many cases more than a year, in order to set up and prepare for an event that, if it was cloudy during the wrong six hours, would be a total bust. It makes our deliberations about where to go to see the 2017 total solar eclipse seem trivial by comparison.

Measurements of the first transit proved largely unsuccessful. Weather foiled many of the expeditions, and a variety of problems caused great variance in the accuracy of the data collected. But they learned from the effort and improved their approaches, and by the time of the 1769 transit, the combined observations narrowed down the distance to the Sun to within four million miles, which was quite an improvement.

Wulf spins a great tale of scientific inquiry, daring (and not-so-daring) adventurers, political intrigue, and fascinating personalities involved in what was arguably the biggest collaborative international scientific event up to that time. It’s a marvelous read and highly recommended.


Transit of Venus

What a great day June 5 turned out to be! My three-day trek to see one of the rarest predictable astronomical events was a success, and I had a marvelous time watching Venus in transit across the face of the Sun.

Venus transit

Though I spent three days on the road to get to weather more conducive to Venus transit viewing than we have in Seattle, there were still clouds, and they made for interesting photos! Shot near Corning, California. Photo: Greg Scheiderer.

The beginning of the day didn’t look very promising. I awoke at about 6 a.m. in Canyonville, Oregon and looked out the window to see pouring rain. I looked at several online weather forecasts, and the outlook had worsened a bit since my last check the previous evening. Still, the prediction was for mostly sunny skies in my target area of Red Bluff, California.

The rain had let up some by the time I hit I-5 southbound at 7:30, but the overcast was complete. Clouds predominated the trip through the Siskiyou and Klamath Mountains; Mt. Shasta was completely socked in, and it was raining off and on as I worked my way south. Once I cleared Shasta Lake and headed into Redding and the Sacramento Valley, the clouds parted somewhat, but there was reason to worry. There was some nasty looking rain in the hills to the west, and plenty of clouds dotted the sky in Redding.

I pushed south. I had targeted Red Bluff as my viewing site because it was the closest spot with a forecast that gave good odds for transit viewing. The National Weather Service had it at less than 20 percent cloud cover for the afternoon. I’d done some internet searching and had three candidate viewing sites in mind: an I-5 rest stop just north of Red Bluff, a city park on the river in downtown Red Bluff, and the Woodson Bridge State Recreation Area just east of Corning, the next town south of Red Bluff. If none of those worked out, or if the weather looked iffy, I could probably get at least as far as Sacramento before the transit began.

I viewed the Venus transit from Tehama County River Park east of Corning, California. Photo: Greg Scheiderer.I checked out the rest stop, but it had too many trees and limited views to the west. The city park in Red Bluff was OK, but also had lots of obstructions. So I headed for Corning. I got to the state park, and it was closed, with a locked gate across the driveway! (Shouldn’t that be noted on the website?) However, Tehama County River Park was just on the other side of the highway, and it was open! It turned out to be perfect! The park is right on the Sacramento River, has a good view to the west, and hardly anyone else was there. There was still a big rain storm to the west, but it looked like it was moving north, so a little after 1 p.m. I decided that Tehama was my place. I still couldn’t stop thinking how badly it would suck if the rain moved in on my California vantage point while there were clear skies back home in West Seattle. Was Captain Cook all wigged out about the weather when he went all the way to Tahiti to view the Venus transit in 1769?

By 2 p.m. I had my telescope set up and collimated, and so had about an hour just to chill and have a little lunch before the transit began. I shortly was visited by the manager of the park, who wanted to find out what I was up to. (A Dobsonian telescope looks a little like a cannon, or a water heater, depending on the direction in which it is pointed.) When I explained that I’d driven all the way from Seattle to find the Sun in order to watch the transit of Venus, this seemed to satisfy, if not necessarily interest, him. He mentioned that, a couple of weeks ago, this same park was packed wall-to-wall with people viewing the annular eclipse of the Sun. (It was well within the path of annularity.) I found this interesting; I didn’t think much of the eclipse, but would have despaired at missing the transit of Venus.

The sky view from Tehama County River Park as I set up to view the Venus transit June 5. Photo: Greg Scheiderer.

The weather held, the rain moved north, not east, and there were only a few clouds around Tehama Park as the start time for the transit approached. As luck would have it, one of those clouds was covering the Sun at the moment of “first contact” as the transit began. But, within a few minutes, the Sun shone through and I let out a gasp! There was the shadow of Venus, taking a little bite out of the Sun!

At right about this time another astronomy buff pulled into the parking lot of the park, well across from where I was, and set up a telescope. And four local picnickers chose a table near where I was in the park, but didn’t seem interested in what the telescope guys were up to.

There were several stretches during the 4 p.m. hour when clouds obstructed our view of the transit, but mostly the weather held and I enjoyed watching the transit and the sunspots and the activity on the Sacramento River. Then around 5 p.m. my picnic neighbors got up from their table, walked closer to the river, put on their eclipse glasses, and looked up at the Sun! Amazing! They knew what was going on, but didn’t bug the telescope guys for a look! Of course, I went over and offered to share my telescope view with them, and they were delighted by the view of the transit. This quartet, too, had been in the park for the solar eclipse on May 20. A couple of them came back repeatedly over the next couple of hours for another look at the transit.

A little before 6 p.m. my neighbor telescope user came by. To my surprise, he was wearing an old-school Seattle Mariners cap! (My own cap of the day was of the Albuquerque Isotopes, the “A” in this case standing for “Astronomy.”) It turns out Kenny, from Port Orchard, Washington, is an astronomy enthusiast, and he and his family were on vacation in California in hopes of finding a good spot to view the Venus transit. How amazing that the two astronomy buffs in an out-of-the-way park near Corning, California turned out to be from the Puget Sound area!

I watched the transit progress for about 4 1/2 hours before the Sun sank into a bank of haze and clouds that degraded the view substantially. I decided to pack it up then and head back to Redding, find a place to rest my head for the night, and then head back home on Wednesday.

Self portrait with telescope on Venus transit day. Photo: Greg Scheiderer.

Viewing the transit of Venus is the high point of my amateur astronomy experience. Part of it is the rarity of the event. The next one won’t happen until the year 2117. That’s 105 years away, and while I’ve decided to try to make it, the odds are against me! More than this, though, it’s understanding of the scale of the universe that makes a Venus transit such an awesome experience. Earth and Venus are pretty close in size, and Venus appears as just a tiny dot on the face of the Sun. I feel so lucky to have been able to see it happen.

As it turns out, if I’d just stayed home, I would have seen the transit, however briefly. Alice Enevoldsen of Alice’s Astro Info, a friend of Seattle Astronomy, held a viewing event at Solstice Park in West Seattle. They had a few glimpses of the transit through occasional breaks in the clouds. Others saw it in the Puget Sound area, too.

I don’t consider myself much of an astrophotographer, but on occasions like this I try to grab a few snapshots just to prove I was there. This Facebook album includes a handful of photos made by pointing my Canon Powershot A530 through the eyepiece of my telescope.

What a memorable day! I drove home from Redding Wednesday and had a wonderful dinner with my sweetie when I got back, right around 7 p.m., about 24 hours after I packed it in on viewing of the transit.

Now to start planning for the next transit of Mercury–May 9, 2016.


My quest for the Sun

Since the 1760s explorers have been traveling hither and yon for a look at a transit of Venus across the Sun. Captain Cook went to Tahiti. Mason and Dixon, before they started drawing lines, went to South Africa. So, too, I follow in that same tradition with a perilous trek from Seattle to Red Bluff, California in an attempt to view the last Venus transit until the year 2117.

The first day of my journey gave only the slightest glimpse of the Sun, which drilled through the clouds south of Salem, Oregon only for a few moments before going into hiding. There was a spectacular thunderstorm going on as I passed through Eugene, featuring the sort of overwrought clouds that are typically associated with the eye of Sauron.

I took up lodging in Canyonville, Oregon, known principally as the home of the Seven Feathers Resort and Casino. I opted for somewhat more mundane lodging at the Holiday Inn Express in town, opening up a rich possibility of Tuesday quips, “I’m not an astronomer…” The Inn has a marvelous view of the casino, and of I-5.

Closed. Rats!

The life of a traveling astronomer is fraught with peril. The top dining choice in Canyonville, Serafino's, was closed Monday night. Best of luck to Katie and JD.

The Inn’s guest guide listed four local restaurants, and Internet research helped me decide on Serafino’s Italian Restaurant and Pizzeria, a small, family-style joint in town. As I headed toward the restaurant on a drizzly Monday night, I passed another of the inn’s choices, a Mexican restaurant–closed. Soo, too, was Serafino’s. Normally open on Monday’s, the eatery had a sign on the door explaining they’d be closed June 3-5 for a wedding. Missed it by that much.

Thus, it was back to the Creekside, right next door to the inn, but part of a big truckstop complex connected with the casino. I’ve never before been in a restaurant that included ads for tires and motor oil on the menu. It also had phones in every booth, presumably so truckers could keep in touch with their sweeties. Trepidation aside, my ribeye steak with steamed veggies and rice pilaf was just fine. That, plus two glasses of Firesteed Pinot Noir, a slice of carrot cake as big as my head, and tip came to just $39.

There’s no sign of the Sun here on transit morning (apart from the fact that it is light outside.) Cloudy and rainy. Onward to California, where the forecast is favorable for Venus viewing.


Weather angst and the Venus transit

Venus will transit across the face of the Sun Tuesday afternoon. This rare celestial event won’t happen again until the year 2117, and Northwest astronomy hobbyists, for good reason a highly pessimistic bunch when it comes to matters of cloud cover, have been warily watching the long-range forecasts since June 5 started to show up on the weather radar.

It is not looking pretty.

2004 Venus transit

The 2004 Venus transit was captured from Germany in this image by Jan Herold. Creative Commons, GNU free documentation license.

As of this writing, Saturday, June 2 at 4 p.m., the Seattle forecast for Tuesday afternoon was for clouds and a 30 percent chance of rain. The prediction for much of the Northwest looks similar. Our best bet as of the moment looks like Goldendale, with a forecast of merely partly cloudy and just a 10 percent chance of rain. (Really, we don’t care so much if it rains as long as it’s not cloudy!) Yesterday Moses Lake and Wenatchee looked promising, but those forecasts have flipped. We’d also been eyeballing the “rain shadow” of Sequim, but even that Olympic Peninsula town now has a wet forecast for Tuesday. The closest “sunny” forecast I am able to find is for Red Bluff, California. Do you roll the dice on an 11- or 12-hour drive, or hope for the best somewhere a little closer?

Many of us will likely be watching the weather forecasts up until Monday evening or Tuesday morning, making some last-minute decisions about where our chances look best for transit viewing, and then high-tailing it to those spots.

Of course, it’s possible, maybe even likely, that we’ll out-think ourselves on this decision. The lore of celestial event chasing is full of accounts of people who have made extreme travel efforts to get to places certain to be clear, only to find those locations socked in while the sky above their own backyards was crystal clear.

Why are we making such a big deal of this? Due to the peculiar geometry of the orbits of Earth and Venus around the Sun, we can only see a Venus transit occasionally. They come in pairs separated by eight years, and either 105.5 or 121.5 years go by before the next pair comes along. Tuesday’s transit is the second of a close pair. Unfortunately, the 2004 event wasn’t visible from the West Coast, and only the end of the transit was visible from the Eastern U.S. as the Sun rose that day. Europe, Asia, and Africa had the best views last time. So this is your last chance unless you make it to December of 2117.

There will be plenty of opportunities to enjoy the 2012 transit from Seattle if the weather cooperates. Events actually begin the evening before, Monday, June 4, at the University of Washington. Astronomy Professors Woody Sullivan and Victoria Meadows will give lectures about the significance and history of Venus transits. The talks begin at 7 p.m. in room 120 of Kane Hall on the UW’s Seattle campus. It’s free, but registration is required.

The UW will have several locations for viewing the transit when it begins at about 3 p.m. June 5. Viewing will also take place at the Pacific Science Center, Solstice Park in West Seattle hosted by Alice’s Astro Info, Battle Point Park on Bainbridge Island hosted by the Battle Point Astronomical Association, and others listed here by the Seattle Science Festival. Many of these sites will at least have online feeds, so participants can watch the transit as viewed from less weather-challenged areas. Other astronomy clubs are likely to be holding formal or informal transit viewings. Check their websites; links to them are at the right.

Seattle Astronomy will likely be at the Solstice Park event, unless we’re beating it to Goldendale.

Remember, don’t look at the Sun without proper protection. You’ll zap your eyeballs. Standard sunglasses are not good enough. This NASA website has some good pointers about transit viewing, eye protection, and pinhole projectors, as does transitofvenus.org.

Let’s hope we don’t miss our chance to see an astronomical rarity!