Skywatch for the week of April 12, 2019
Tue Apr 16, 2019 DIRT ON THE MOON While you’re looking at the moon tonight, take a moment and think about all that dirt up there on its surface. Dirt on the moon is called regolith. So where’d all this dirt, sorry, regolith, come from? Now, dirt on the earth makes sense: we have lots of surface erosion, due to the action of wind, water, ice, and so on. But there’s no weather on the moon, so how come there’s dirt? Here’s a clue: you’ll never see a meteor in the moon’s sky, because there’s no air. Without an atmosphere, nothing stops those tiny bits of dust, (and believe me, outer space is littered with dust!) This debris is moving at a hundred thousand miles an hour and it pulverizes the moon. It’s like a very subtle form of sandblasting – lots of tiny bombardments that earth doesn’t experience, thanks to our atmosphere, which simply makes the dust vaporize high up, lighting up the sky where they become shooting stars.
Wed Apr 17, 2019 NAME THAT PLANET 2 Let’s play “name that planet.” I’ll give you the names of some of the features found on a particular planet, and you try to identify it. The first planet has features like Maxwell Mountain, Cleopatra, Amelia Earhart, Sacajawea, and Mead, plus two continent-sized land masses named Ishtar and Aphrodite. The planet is Venus, and its features are typically named after love goddesses or famous women in history. Now try, Tombaugh, Norgay Mountains, the Sputnik plains, Sleipnir, Tartarus, Balrog and Cthulhu. That would be Pluto. How about the plains of Utopia, Chryse and Amazonis, or the Hellas basin, the Tharsis bulge, the Argyre basin, the Mariner Valley or Mount Olympus? That’s Mars. Where do you find the Caloris basin, or craters named Lovecraft, Bach, Beethoven, Velazquez, Brahms, Cervantes, Chopin, Tolkien, van Gogh, Shakespeare or Mozart? These names of artists, musicians and writers can be found on Mercury.
Thu Apr 18, 2019 STEAM TALK: COMFORTABALY NUMB Dr. James Agnew, who teaches biology here at Indian River State College, will be giving a talk Saturday afternoon at IRSC’s Hallstrom Planetarium. It’s part of our new “Saturday Afternoon Steam Talks” series, and it starts at 4 pm. The lecture is titled, “Comfortably Numb: The History and Science of Anesthesiology,” and in it, Dr. Agnew will discuss some of the early methods of relieving pain during operations and visits to the dentist’s office, and how modern anesthesiology is being practiced today. After his talk, there will be a short presentation in the planetarium theater where I will show you some stars and constellations that are currently visible in the evening skies of April. This talk is free, and everyone is invited. Again, the lecture is at 4 pm on Saturday, April 20th in the Hallstrom Planetarium theater on the Fort Pierce of Indian River State College.
Fri Apr 19, 2019 APRIL’S FULL MOON The moon is full tonight. This is the first full moon since the beginning of Spring, so it’s called the Paschal moon, which determines when Passover and Easter occur each year. Easter always occurs on the Sunday following the first full moon of the spring season, it’s what folks used to call, a “moveable feast,” because the date of the observance changes from year to year. Last month, the full moon happened just a few hours before spring, so Easter was delayed until this coming Sunday. Since spring is underway, the Sioux Indians call April’s full moon, the Moon of Greening Grass; to the Winnebago, it is Planting Corn Moon. The Mohawk knew it as “Onerahtokha,” the budding time, which is similar to the Kiowa’s Leaf Moon, as this is the time of year when new leaves form on trees. The Cheyenne Indians speak of it as the Moon When the Geese Lay Eggs. And to the Cherokee it is the moon when ducks return.