Astro 28K: Field Astronomy at Carrizo Plain National Monument

Apr 23-25, 2004

It was a Great Trip! Check out the Post-Trip Highlights.

This class will focus two early morning comets, a lunar grazing occultation, and on the unique geology of this newest National Monument in California, and put it all into an astronomical context. The San Andreas fault zone has created a wide, semi-desert valley which harbors one of the last large tracts of rare native plants and animal ecologies in California. Because of this, the Nature Conservancy and the National Park Service bought this land and preserved it, primarily for the endangered species and not for visitors - perfect for crowd-shy astronomers!

Carrizo Plain National Monument is most famous for those pictures you've probably seen of dramatically offset creeks and drainage due to the San Andreas Fault. It also has spectacular wildflower displays in the early spring. Soda Lake, an alkali lake created by uplift due to the fault, has surrounding marshlands and abundant rare and native wildlife. There are few trees and horizons are good. Carrizo provides a good setting to demonstrate and discuss crustal processes common to the inner planets as the area is a graben formed by the actions of the San Andreas Fault; one of the great tectonic plate boundaries on our planet.

The beauty of this land, especially in the spring time, has inspired both ancient peoples of the Chumash tribe, who left fascinating inscriptions at Painted Rock Sacred Site near our camp, as well as modern poetry. Learn more about the Chumash inscriptions here, here, here, and see some of the markings on Painted Rock itself here. My friend and photo workshop colleague Dave Wyman took incredible images during his photo workshop here in the Spring of '03, including the image at upper left. From my recent visit, the rain patterns this year made for an early spring, and the peak wildflower season is now over. However, there are still flowers if you look, and the mosaic of greens and browns and yellows that color the plain have their own beauty.

Learn more about this little known treasure of California here, here, and here, and at the Sierra Club's page here. A geologic tour can be found here. Dave Wyman's Image Quest photo workshops have produced some beautiful images from Spring, seen here.

Astronomical Highlights

Our evening lectures will focus on the role comets have played in the formation and evolution of the solar system, and on new and puzzling data which is casting doubt on some central theories on comet evolution.

A Grazing Lunar Occultation: We will be observing a lunar grazing occultation on Saturday evening's cresent moon. The 9.2 magnitude star will be faint for visual observers, but should be easy for all of us to observe with our PC164c video camera and TV monitor. Lunar grazes are pretty cool to watch. Check out this Quicktime .mov file of a bright graze Sept 17, 2003, speeded up by a factor of 6. Venus and Mars will be in conjunction in the star fields of Gemini in the evening sky not far from the moon. We will also have the north galactic cap centered high in the evening sky, giving us great views of the Virgo and Coma galaxy clusters. The winter Milky Way of Auriga and Gemini will still be high enough in the dark western sky to give good views of open star clusters and nebulae.

Two Nice Comets! And, most interesting, we will be perfectly positioned to see Comet T7 LINEAR as it makes its closest approach to the sun on this weekend. It will be only 0.6 AU away; inside the orbit of Venus, and the strong solar heating gives good prospects of generating a nice tail reaching up from the eastern horizon. The comet is currently expected to be magnitude 4 during this weekend - a binocular object low in Pisces in the eastern sky before dawn. It could provide nice photographic opportunities above the fault-carved mountains bounding the eastern edge of the monument.

And, just discovered, is the new Comet F4 Bradfield, making a deep plunge near the sun and then rapidly moving north into our pre-dawn sky. It should be about 4.8 magnitude for our weekend trip, 6 degrees above the horizon also in Pisces just before dawn begins. Two binocular comets in the same constellation at the same time. That will be a first for me. However, comet expert John Bortle warns that this is a small comet and it would not be unusual for it to be completely melted away by the sun. If so, we won't see anything. But today (April 17) it's passing perihelion and looking quite spectacular on the SOHO images.

Day Trip Highlights

Shortly after dawn early risers are welcome to join me for an optional session of landscape photography from camp. Early morning light on Soda Lake, the dramatic Temblor Mountain range across the plain, and macro photography of native grasses in morning light should make for beautiful images. Later, after I cook up one of my famous crepe breakfasts for the crew, we'll examine the sun using our solar filter, and hopefully Karl will be able to bring along De Anza College's new solar H-alpha filter telescope. Then we'll go to the visitor's center to learn more about the Plains and get access to the trail to Painted Rock. We'll then take two self-guided geologic tours to explore the offset stream beds and surface traces of the San Andreas Fault, calculating creep rates and relating to our earlier experiences with the fault at Pinnacles National Monument. Afternoon break will allow students to hike - or mountain bike - Caliente Peak's trails, explore the marshlands, or just relax.

The Selby Rocks are close to our planned campsite. In fact, one of the finalists for our camp area is right where this photo was taken.





In order to see the comet and have good horizons we will not be camping in either of the two primitive campgrounds in the park. Instead, we will be camping on BLM in the Caliente Mountains with wide views of the plains and the Temblor Range across the plains. Plan to bring your own water as there will be none at Carrizo. We'll bring tables from the observatory, but you should bring beach chairs. Official bathroom facilities will be 1 mile away, but of course there are plenty of bushes for the adventurous. If you did not attend the pre-trip meeting Wednesday 4/21, here are the directions to get to our campsite...

Directions to camp. Get on Hwy 101 and drive south to Paso Robles. IMPORTANT! This is a MANDATORY gas stop! This is the last gas station you'll see until your return drive through Paso Robles on Sunday - that's a bit over 200 miles roundtrip. So whether you need it or not, get gas here now. Then head east 16 miles on Hwy 46 to Shandon. At the Shandon turnoff, go into the little town and turn right (south) on Truesdale Rd. Stay on it heading south and it'll join with Shell Creek Rd, which you continue on for another 15 miles or so until it hits and ends at Hwy 58. Go left (east) until you enter Carrizo Plain (you'll see signs for "Carrisa Plain" and "Carissa Fellowship Church") and it'll be obvious you're out of the hill country and in the plains. Turn right onto Soda Lake Road, where there's a sign for "Carrizo Plain National Monument". Drive south through the sparse community of California Valley and into the National Monument, past Soda Lake and note the dirt road to the Goodwin Education Center (park visitor center) on your right. 1 mile after Goodwin you'll see a sign "Selby Camp/Caliente Ridge". Turn right onto this dirt road and drive about 4 miles, into the Caliente Range foothills and you'll come to a fork in the road right where there's an old abandoned ranch. To your left will be "Selby Camp". You will stay to the right "Caliente Ridge" and go through an open gate. Note your odometer! You now go precisely 1.15 miles up this road winding into the mountains and you'll come to a fairly flat area with parking and we'll be right there. That's camp. Jeff should get there by about 4pm Friday. I'll be there by 5pm. Some students might even get there earlier. Here's a link to the topographic map of our campsite - Camp is the "x" in the middle. Play with Topozone's controls to see a wider view and how the dirt road to camp looks. We're not in a campground, so bring your own water and pack it in/pack it out!

Pre-trip checkout Apr 17/18

The weekend before our trip, I drove down to the campsite I've settled on- to hopefully get timings of the Tanete occultation, double check things one last time, and get my first look at Comet T7 LINEAR.. ClearSkyClocks said I'd have a clear break between storms and that proved true. Weather was cold right after this storm. Frost covered everything before dawn. But skies were very dark and my Milky Way photos should be awesome. Got a possible blink (or miss) on the occultation. Comet T7 LINEAR was about 4.7 magnitude, although some lingering clouds made it hard to estimate, it seems consistent with the newest morning sky readings from elsewhere. I'm happy that this site is the best overall for our needs - it's got a beautiful view of the plains and Soda Lake, good horizons all around, and T7 LINEAR is in a dark rift between the distant glows of Bakersfield and LA.

Sunday morning I relaxed and did the watercolor painting seen above of the view from our campsite. Here are photos from the checkout trip...

at Soda Lake nature walk, and another view

at Soda Overlook looking towards the Caliente Range. 5,200 ft Caliente Peak is the highest peak in this picture.

In the late afternoon a final rain shower produced a beautiful rainbow in this picture taken from our campsite. Note the San Andreas Fault scarp catching the setting sun's rays across the middle of this picture. We'll be exploring the scarp on Saturday. Another picture of the rainbow is here. Weather for our weekend trip is expected to be warm and clear.

and, here is the view from our campsite looking towards Soda Lake.