Monday, May 16, 2022

How it Was: Lunar Eclipse of May 2022

This evening's lunar eclipse was visible all across North America, and it was spectacular! I hope you were able to see it, but if you didn't, here is some sense of what it was like.

Out here in California the eclipse was already underway at sunset, and most of the Moon was already in the Earth's shadow. It was kind of strange to see a "crescent" Moon rising in the east as the sun set in the west.

The sliver of the sunlit lunar surface grew smaller and smaller, and the Moon seemed to disappear in the deepening dusk. The darkened face of the Moon was actually glowing with red light refracted through the Earth's atmosphere, but it took a few moments for the sky to grow dark enough to see it.
The red of the Blood Moon became visible, and then I had a bit of a surprise. It is hard to see stars in the immediate vicinity of the full moon because it is so bright. But if you look in the picture below, look at the 10:30 position of the disk, and there is a star emerging from behind the Moon! I've never seen this happen before.
A few moments more, and the moon had moved away from the star, and several others were visible as welll.
It wasn't easy holding the camera still enough to catch the stars as well. I guess I should just use a tripod, but what's life without challenges? I only deleted 30 or 40 shaky shots...
This was an unusually long period of totality for a lunar eclipse. After around an hour, the bottom edge of the Moon began to glow brighter as the orb moved closer to the edge of the Earth's shadow.
And then just like that the Sun began to shine on the lunar surface again. 
The red disk disappeared and the stars dimmed and disappeared once again.
And then it was over, and our bright full Moon had returned. And that is how it was! Thanks to our friends Jeanne and Barry for a nice evening with a porch overlooking the Tuolumne River and a perfect moonrise!



 

Monday, May 2, 2022

Are You Sure That Enclosure Will Be Enough? New Dinosaur at MJC's Great Valley Museum!

I couldn't help but recall a certain famous movie opening: guys in hardhats unloading a dinosaur at a new park named after a geological time period...Cretaceous Park or something like that. Things went scarily wrong, and movie history was made.
Today's experience didn't end badly though, since the dinosaur in question was a plant-eating Parasaurolophus and it wasn't a living specimen. It was one of the final additions to the Great Valley Outdoor Nature Lab at the Great Valley Museum on the campus of Modesto Junior College.

The exhibit commemorates a little-known fact about our county: it was the site of the first reported discovery of dinosaurs in California. Back in 1936 17-year-old Al Bennison was exploring Del Puerto Canyon in the Coast Ranges along the western part of Stanislaus County looking for shell fossils when he found bones scattered on a slope. He showed them to his science teacher who reported them to the paleontologists at U.C. Berkeley. It proved to be the partial remains of a Saurolophus, which was one of the last dinosaurs that ever lived on our planet, one the last groups in existence when the gigantic asteroid hit the planet (or when the volcanoes blew, or whatever else did them in). They lived in the latest part of the Cretaceous Period, which is well represented by sedimentary rocks in our region. The rocks are marine in origin, which tend not to be good places to search for dinosaurs, but sometimes a carcass would float out to sea, as this one did.

The creatures were gigantic, on the order of thirty to forty feet long, weighing several tons (our model is a 1/2-sized replica at 16 feet long). They were plant-eaters, with teeth well-adapted to grinding twigs and leaves. Whether they swam or not has been a topic of discussion and debate. Some argue that they had few other defenses from predators, so that swimming was necessary to escape from being eaten. Others suggest that they lived in herds that provided protection. California designated a species of Saurolophus, Augustynolophus morrisi, as the state dinosaur in 2017.
For comparison purposes, here is what the Saurolophus looked like. Source: http://en.wikipedia.org/wiki/Saurolophus
We thought it was important to put a dinosaur on display as we planned for the new Great Valley Outdoor Nature Lab. Dinosaurs certainly capture the imagination of our children (and not a few of our adults), and it is a good thing for our students to know that our county played an important part in the paleontological discoveries in our state. When students realize that one of their own (however long ago) made an important find, they also can visualize themselves as a paleontologist or geologist making important contributions to science. The concrete squares covered by orange tarps are mock paleontological digs where students can experience the sense of discovery that all paleontologists live for.
So why a Parasaurolophus, and not the Augustynolophus morrisi or other 'real' Saurolophus? That's easy: none of the marketers of dinosaur replicas offer any for sale, at least far as I could find. We figured that a similar species was better than none at all...
Trying hard not to be trampled to death 
What a great day for geological education in our county. I just hope the containment structure works! It just won't do to have wild dinosaurs running around on our campus...