Astro 28K: Field Astronomy at Carrizo Plain National Monument

Apr 11-13, 2008

Post-Trip Photo Page

Check out the Post-Trip Highlights of the Spring 2004 Trip and Spring 2006 Trip

This class will focus on 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. Early April should be near the peak of the wildflower season. There are lupine, California Poppy, and a wide range of other flowers which will carpet the hillsides and flat lands. 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

Evening skies in early Spring will give us views of the Orion star formation region, the brightest open star clusters in the sky, and a cresent moon to enable us to study the geology of the moon. This link shows the lunar occultations occuring during our weekend.

A Grazing Lunar Occultation: We will be observing a lunar grazing occultation on Friday evening's 43% cresent moon. The moon's northern edge will just graze an 8th magnitude star in Gemini, making the star disappear and reappear hopefully many times as it is covered and uncovered by the mountains and valleys on the dark side of the moon. The graze happens at 10pm sharp, time enough for us to finish dinner, clean up, and get down to to set up stations near the San Andreas Fault, just east of Soda Lake (see map at right). The 8.6 magnitude star will be bright enough for visual observers, and will 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. The moon this night will also make a close conjunction with Mars - the two are only 1 degree apart and are worth a photo.

Here are the graze predictions, for my reference. Another Google Earth map of the graze path is here. And the profile for the graze is shown at right.




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 and flowers 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. The wildflower season will be in full bloom. Check here for the latest reports on the wildflowers.



Pleistocene Comet Impact Wipes out the Clovis Indian Culture and the Great Mammals of North America!

In 2007, geologists discovered evidence from two dozen sites around North America, of a giant comet impact which hit at the end of the last Ice Age in North America, 13,000 years ago. Just like the dinosaur killing event 65 million years ago, this impact left a dark layer of carbon spherules, micro-diamonds, and iridium-rich debris, combined with the ash of massive wildfires which burned the continent to the ground. This evidence is also visible in California. However, as of the writing of this webpage, no mainland sites have been searched (2 sites in the Channel Islands have provided evidence so far). I've thought about where evidence might be found on the mainland, and Carrizo Plain has some uniquely favorable characteristics - it is a depositional region with semi-desert aridity, it is cleanly sliced by the active San Andreas Fault, and micro-basins might be expected to show, in the right spots, this 13,000 year old deposit in off-set stream bed or sag pond locations. I'll do some more work on where would be best, and I would like to bring along my geologist hammer and a shovel or two and see if we can find and collect evidence of this layer here. If we're successful, it will be very important science! Read a paper on this event here.




The Selby Rocks (left) are close to our planned campsite. In order to have good horizons we will not be camping in either of the two primitive campgrounds in the park (which are kind of boring, actually). Instead, we will be camping on BLM land 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, 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 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 T's with 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 (The 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" but 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 hills and you'll come to a fairly flat area with parking and we'll be right there. 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!


Other Photos from Carrizo Plain...

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.


Late Breaking News...

* We are permitted to have a fire. It must be within a fire ring, and we need a permit. However, we need to get the permit from the visitor's center and the visitor's center (the Goodwin Education Center) is only open from 9am-4pm. If someone gets there before 4pm on Friday, please stop by the Goodwin Center and get a fire permit. If not, then we can always skip the fire on Friday and get the permit when we go down there on Saturday. After all, we'll be pretty busy Friday night with grazing anyway.

* Simmler Road (the road that goes between the two halves of Soda Lake) is in good shape and will be our graze road. So, if you arrive at 8:45pm and want to skip going up to camp, just join us on Simmler Road. I'd say, just drive a bit onto the road (nice wildflowers there) and wait for me to drive by and guide you to the site, or if you're closer to 9pm or later, then just drive along that road until you find us. We'll be no farther than the far end of the lake or a bit farther; that's maybe 3 miles? or so.

* The water at Selby Camp doesn't pass State requirements for minerals and is "not potable". But it's probably just fine for cleanup. FYI. Otherwise, there is no water in the park, not even a drinking fountain at the Goodwin Center. Bring your own certainly for drinking!

* Weather forecast - warm days in the high '70's, cool nights.

* This is a "Good" year for wildflowers (unlike last year, which was poor, and unlike 2005, which was amazing). There'll be more than the usual tourists out/about photographing the flowers. Not many campers probably.

* I have more handouts for you when you arrive; on grazes in general and our graze in particular, including the profile and where the star will be (see pix above too), and also a handout on planetary science and local and California Geology.

Our Tentative Schedule


Before 6pm: Get your carpools together and drive down. Plan to arrive before 6pm: Arrive at the campsite and set up tents, kitchen. I'll be leaving about 1:30 pm and arrive by 6 pm is my guess.

7pm: Start dinner. I'll be fixing a hearty meal, with your help. Enjoy the sunset light on the beautiful plains below us.

8:30pm: clean up, have a star hop w/ laser pointer, and prepare for carpooling back down to the plain for the big lunar graze!

10:00-10:05pm - Observe the graze from 2 or perhaps 3 stations we'll set up just north of Soda Lake. After the graze we re-convene (we'll be less than a mile apart in our different stations) and review data, perhaps get GPS readings, and then head back up to camp.

11pm - we'll decide if we want to set up scopes for more viewing, or weather you've had it for the day.


I'll get up by 7:30am and start fixing the batter for my famous French Crepes breakfast.

8:15-9pm Breakfast, then cleanup. Consolidate cars

10:00am-12:00 noon: Visitors Center, and tour the Chumash sacred site at Painted Rock.

2:00pm-6pm: Study the San Andreas Fault near Wilson Creek, go to the Soda Lake overlook and access points, search for good spots to find Pleistocene Impact Debris Layer (if we're very lucky!).