Can't wait for the next comet -- Halley's or otherwise -- to penetrate the Earth's atmosphere? Why not make one of your own?
The universe's mysteries can
be unraveled via flour, dirty
snowballs and Alka-SeltzerBy Scott Vogel
svogel@starbulletin.comIt's very simple, actually. Just take some water, mix it with ice, fold in some carbon dioxide and a generous helping of dirt -- and voila! -- a comet. OK, so your comet won't fly through the atmosphere, terrorize Téa Leoni or send Americans fleeing to underground shelters (a la "Deep Impact"). Then again, yours will have the virtue of duplicating the exact recipe of the real thing. Can Hollywood say that about its comets?
Or dirty snowballs, as astronomer Jim Heasley calls them, speaking about the activities and seminars planned for Saturday's open house at University of Hawai'i at Manoa's Institute for Astronomy. This third annual event offers a rare opportunity for kids (and their parents) to not only glimpse the goings-on at a world-class research facility but also get a handle on some of the abstruse jargon -- e.g., dark matter, supernovae, starburst galaxies -- that make astronomy such a forbidding discipline.
But back to the dirty snowballs, Jim.
"Dirty snowballs don't mean a lot to kids in Hawaii, so we have a shave ice machine and we mix it all with dry ice and get this melting thing -- that's exactly what happens when a comet comes into the atmosphere."Expect more in the way of creative explanations of complex phenomena during the daylong event, which will combine mini-lectures on such topics as archeoastronomy with opportunities for kids to create their own craters.
"We drop objects and let them fall into a bed of flour," Heasley explains, "and the energy of the falling thing and the compactedness of the flour are similar in relationship to what happens when an object crashes to the ground. So you get a crater just like you see on the moon." Other household products employed for the purpose of deep space exploration include Alka-Seltzer, which figures prominently in the open house's popular bottle rockets venue.
There's a serious side to all this frivolity, and one that goes beyond the dissemination of scientific knowledge. We're talking of course about PR, and the open house is a powerful piece of advertising for the institute. Or as Heasley puts it, "We're proud to be one of the better, well-recognized units of the university and events like this are ways to let the public know that they're getting quality for the money."
They're also getting windows onto the world's farthest reaches. This is, after all, the same group of folks who oversee the Big Island's Mauna Kea Observatories, which contain the world's largest optical/infrared telescopes. Needless to say, those lumbering machines weren't available for transport to Saturday's open house, but three high-powered telescopes will be on site. Two will be aimed at the sun -- protective filters attached to make viewing safe for the human eye -- in order to explore the hydrogen alpha line, "which shows a lot of the active regions of the sun, the parts which can interfere with radio communications." Sunspots will also be on view, weather permitting.
A third telescope will be trained on Venus, a planet that can be exceptionally difficult to see during the daytime (other than during the very early morning).If the preceding gives you the impression that the open house is only for kids and astronomical amateurs, read on, for the day's events also include mini-lectures by seven of the UH Astronomy Department's most distinguished professors, each focusing on one of the field's many enduring mysteries.
"One of the things we've discovered in astronomy over the last century is that most of the mass present in the universe is not the same matter you and I are made of," says Heasley, speaking of Gareth Wynn-Williams' talk on "Dark Matter: Science's Biggest Mystery." And don't be ashamed if you haven't heard of dark matter. It is, after all, invisible despite occupying what astronomers estimate is 75 percent to more than 90 percent of the universe's mass. "We can tell it's there because of gravitational pull, but what it is we have no clue."
Another intriguing and longstanding mystery concerns the evidence of past life on Mars, a topic dear to the heart of planetary astronomer Tobias Owen. Again, Heasley sets the stage, saying that "Mars in the past was a very warm, wet planet. Now it's pretty much a dry, cold desert. Did it in the past develop life like Earth only to have it die out?"
And then there's the question of whether a giant asteroid the size of Texas could be on a collision course with Earth, with the potential to create mass panic and send Bruce Willis and Ben Affleck scrambling in all directions. The short answer, apparently, is yes, as David Tholen will detail in his aptly named mini-lecture, "The Threat from Earth-Approaching Asteroids." As Heasley notes, a very large asteroid hit the Earth around 65 million years ago, an event that coincided with (caused?) the demise of the dinosaurs. "What we think happened is that the impact caused the equivalent of a nuclear winter, changing the climate for some period of time. That could happen again."
And not unlike the way it happened in the film "Armageddon," with a last-minute shove of the asteroid off course. Of course, "In the movies, they didn't detect it until the last minute, so they had to give it a big push." Tholen's work involves finding ways to identify such calamitous collision courses well in advance, perhaps hundreds of years before the threatening object enters the Earth's atmosphere, when just a small push might cause the asteroid to ultimately miss its target by a wide margin.
Hollywood, like Saturday's open house, may be accused of simplifying things, but that doesn't mean it doesn't often approximate some version of the truth.
"It won't be Bruce Willis," notes Heasley, "but the idea is a valid one, if you can give the asteroid a push early enough."
Third Annual Institute for Astronomy Open House: Final frontier
When: 10 a.m. to 4 p.m. Saturday
Where: 2680 Woodlawn Drive, Manoa
Cost: Free
Call: 956-6531
Click for online
calendars and events.
