There were lots of oohs and aahs Sunday at the Seattle Astronomical Society annual banquet as Scott Kardel, public affairs coordinator at Palomar Observatory, dazzled attendees with some of the latest work being done with the legendary Hale telescope and other instruments at Palomar.
Kardel talked a little about the storied history of Palomar, pointing out that famed astronomer Edwin Hubble made the first astrophotographs with the 200-inch scope. Interestingly, with improved adaptive optics set to be installed at the scope this spring, they’re hoping to get better images from the ground-based telescope than we’re getting now from the Hubble Space Telescope. The new system will use a laser guidestar and nearly 3,400 actuators to adjust various secondary mirrors.
“We will be able to do visible light adaptive optics, which nobody in the world is doing,” Kardel noted. “Because our telescope is bigger than Hubble, if we can correct for the atmosphere we can get visible-light images sharper than Hubble.”
The whole system looks like a modern-day Rube Goldberg device, with more than a half dozen mirrors reflecting images to various devices.
While it doesn’t hold a foot-candle to the one to come, Palomar’s current adaptive-optics system is pretty good, with 241 actuators that adjust a secondary some 2,000 times per second.
“It’s all done with mirrors,” Kardel quipped, with a caveat. “We don’t bend the primary mirror of the Hale telescope. It’s two feet thick and weighs 14 and a half tons.” Even so, the results are fantastic.
“We can get the 200-inch telescope to hit its theoretical resolving limit,” Kardel said. “You correct for what the atmosphere is doing faster than the atmosphere changes.”
The results have been some amazing photos. Among the most breathtaking ones he shared were those shot the night NASA slammed the LCROSS probe into the Moon, hoping to find evidence of water. Media coverage suggested the resulting dust plume might be visible from Earth, even with backyard telescopes. Palomar was watching and took some beautiful landscape photos.
“Tragically, there was nothing to see,” Kardel said of the plume. “We were the first to report there was nothing to see.”
There’s lots of other work happening at Palomar. Mike Brown did his sky survey there that led to the “demotion” of Pluto, discovering many trans-Neptunian objects. “Mike used the 48-inch telescope at Palomar to do that work, and revolutionized what we know about the Kuiper Belt,” Kardel said.
Palomar astronomers also have found nearly 27,000 asteroids and 992 supernovae at last count.
Light pollution is something of a threat at Palomar. Kardel pointed out that the population in the area was a mere 290,000 back in 1930 when the site was selected. Nobody really expected it to get to today’s level of about five million. Seattle astronomers don’t much like our clouds, but Kardel said they can be useful at Palomar.
“We like clouds, because often we get clouds that are below us. The clouds come in from the ocean, and it’s like pulling the drapes on the cities,” he said. “Palomar gets darker nights when the marine layer blows in and we’re above the clouds and the cities are underneath. We can actually get a sky that is comparably dark to what we had in the 1940s.”
Kardel is clearly doing work that he loves, and it came through with his enthusiastic presentation.
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