Air Date: Week of August 3, 2001

Despite the advances women have made in the sciences, few women have entered the field of astronomy. Lucy McFadden is one of them. The NASA scientist is trying to discover the make-up of comets and asteroids. The answers may provide clues to the beginnings of our solar system and earth itself.

Transcript

CURWOOD: Every summer, the Perseid meteor shower delights people in the northern hemisphere, with the display reaching its peak on August 12th. While some of us need an excuse like the Perseids to think about the night sky, Lucy McFadden does not. The University of Maryland astronomer has spent more than two decades investigating the mineral make-up of asteroids and comets and how they might relate to origins of life here on earth. Living on Earth's Cynthia Graber has this profile of Professor McFadden.

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GRABER: With the turn of a key, an observatory ceiling pulls away from whitewashed concrete walls. Lucy McFadden gazes up at the heavens.

McFADDEN: And the cloudy skies of College Park.

GRABER: McFadden's love affair with the night sky began with telescopes and observatories like this one, five minutes from the University of Maryland, College Park, where she's a professor. As the ceiling retreats, a starless sky is revealed overhead. Despite the completely dark parking lot and surrounding fields and forest, conditions aren't optimal for star-gazing. An observatory in highly populated College Park isn't exactly the same as what she experienced while doing graduate work at the University of Hawaii.

McFADDEN: When you're on top of a mountain, outside, in clear skies, you actually feel like you're floating in space. It feels like the sky comes down and envelopes you and it's all around you. And looking up, I mean, it's a physical experience as well as a mental experience. So it's pretty awesome.

GRABER: One of the most exciting days of McFadden's career didn't take place while gazing at the heavens, but in a stand of bleachers in Florida.

ROCKER CONTROL: Two minus 11, 10, 9, 8, 7,--

GRABER: Back in 1996, she stood shivering in brisk February air as she watched the NEAR Shoemaker spacecraft lift off.

ROCKET CONTROL: We have ignition, we have lift-off, of the Delta Rocket, carrying the NEAR spacecraft, bound for the asteroid Eros.

GRABER: It was heading on a four-year journey to intercept the asteroid Eros. Its goal: to orbit the 21 mile long space rock for a year. If the mission were successful, it would provide the first close-up views of an asteroid.

ASTRONAUT: We've ignited the other three solids and all six of the first set are off.

McFADDEN: It was tremendously exciting, and it was also scary because something could happen at the launch, but, ah, it was very gratifying to see it go off into infinity.

GRABER: NEAR Shoemaker finally met up with Eros, a year ago February, and spent the past year sending information from its camera and other scientific equipment. McFadden is one of a few dozen scientists interpreting the slew of data. This isn't McFadden's first encounter with an asteroid. In the late 1970s, she broke new ground in asteroid research with her Ph.D. dissertation.

In order to understand what she did, you need to know that every mineral reflects sunlight by different amounts, at different frequencies--its own signature, so to speak.

McFADDEN: I did a survey with a telescope, measuring their reflected sunlight spectrum, to see what kind of mineral signatures I could get.

GRABER: McFadden was the first scientist to use this technique to figure out what minerals make up the surface of a number of near-Earth asteroids. What does that matter? Well, planets are large bodies that heated to high temperatures and then cooled. If the asteroids had been part of a planet, then the heating process would have caused complex minerals to form. But there was a second possible scenario.

McFADDEN: Are they small bodies? Have they always been small bodies and never heated to high temperatures? In which case, we would study the asteroids and learn about the pre-planet material of the solar system.

GRABER: And that's exactly what she found. Near-Earth asteroids don't have these complex minerals on their surfaces. They never did break off from some larger planet. Rather, they're the primordial building blocks of the solar system. In essence, they're a window onto the very beginnings of our planetary neighborhood, and maybe even onto the beginnings of Earth itself.

McFADDEN: What we learn about the surface and the structure of Eros will tell us something about the pre-Earth time. So I can't predict what that's going to tell us about the formation of the Earth, but we'll figure it out eventually. It's just going to take time.

GRABER: Her research is what claims that bulk of her attention; that is, when she's not attending her daughter's soccer games. McFadden says that pure scientific knowledge isn't the only reason people are interested in the cosmos.

McFADDEN: We have to deal with everyday life, with sickness and war and natural disasters, and we can look at space and recognize that things are happening out there that are out of our control. And it's awesome and it's beautiful. So I like to think that people find cosmic relief in the universe.

GRABER: For her next project, McFadden will be part of the scientific team for the mission Deep Impact.

McFADDEN: We're looking inside of the comet. To do that, we have to dig a hole in the comet.

GRABER: NASA is planning to launch a spacecraft that will shoot off an almost 800 pound projectile into Comet 9P/Temple 1, creating a crater the size of a football field. This will allow scientists a first look at what's hidden inside a comet, deep below its solid frozen mantle. Comets are rich with carbon and water, the building blocks of life. Billions of years ago, comets constantly bombarded the Earth. Some scientists believe these crashes could have brought the elements that helped create conditions perfect for the beginning of life. Excavating below the crust of this comet may provide some clues.

McFADDEN: Will that tell us whether or not comets produced the atmosphere on Earth and brought us the carbon compounds that came to life? Not directly. But, it will give information. So, Deep Impact is a stepping stone to the issue of the origin of life.

GRABER: No matter what information Deep Impact provides, or where her research takes her next, McFadden says she'll continue to push the balance of our knowledge of the solar system, and maybe in the bargain we'll ultimately learn something about our own beginnings. For Living on Earth, I'm Cynthia Graber.

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Links

Deep Impact
Near Earth Asteroid Rendezvous Mission">