Beth Brown

Astrophysicist, X-ray astronomer

Background:

As a young girl, Beth Brown was fascinated by television programs such as Star Trek and movies like Star Wars. Space held a special fascination for her. “Beth was always looking at the sky,” her mother Frances recalls.

Work:

Dr. Brown studied X-ray emissions from distant galaxies. X-rays are produced by some of the most exotic objects in the universe – black holes, quasars, and neutron stars. Dr. Brown was doing what she loved, exploring the universe through her work, and sharing her passion with others.

Frances Brown remembers that her daughter “knew how to explain scientific phenomena and her projects in a way that included you in her world and left you with more knowledge that you started with.” In 2008, Dr. Brown became the Assistant Director for Science Communications and Higher Education at the Goddard Space Flight Center. She also returned to her alma mater, Howard University, where she worked to reach out to young people to encourage their interest in science.

Tragically, Dr. Brown’s life and career were cut short when she died suddenly on October 5, 2008. Dr. Beth Brown, a respected scientist and passionate teacher, was 39 years old. Who will continue her work?

For to whom much is given, much is required.

Flossie Wong-Staal

Molecular Biologist, cloned and sequenced the HIV genome

Background:

Flossie Wong-Staal never thought she’d be a scientist. As a child in Hong Kong, Flossie Wong was more interested in literature and poetry. However, when she went to college in the United States, Wong became fascinated by the new discoveries of molecular biology, such as the structure of the DNA molecule. Discoveries such as this were making biology into an exact, and exciting, science.

Work:

Flossie Wong-Staal works with living genetic machines known as retroviruses. In fact, she was among the scientists who pioneered this field. As Wong-Staal and her colleagues learned about retroviruses, they wondered if such viruses might play any role in human diseases.

They soon found their answer. Two devastating diseases, T-cell leukemia and Acquired Immune Deficiency Syndrome (AIDS) both are caused by retroviruses attacking human cells. Wong-Staal’s team helped determine the entire genetic sequence of HIV, the virus that causes AIDS. It was a giant step in finding treatments and an eventual cure. Wong-Staal encourages students today to find their passion and pursue it relentlessly

Keats said, ‘Beauty is Truth, and Truth Beauty.’ I guess in science I get some of both.

Hope Ishii

Astromaterials Scientist, studying comet fragments from the Stardust space probe

Background:

The daughter of a military family, Hope Ishii lived all over the world as a child. Hope grew up without a television in her home. Instead, she and her sisters took nature hikes and invented ways to feed their growing curiosity. They studied birds, rocks, flowers, whatever they could find.

Work:

Ishii was an avid reader growing up, but also liked to use her hands. She began studying machines, and experienced the thrill of discovery when she finally understood how a particular machine worked. Ishii’s parents encouraged her to consider engineering as a career, but she soon found herself drawn in another direction, as she became fascinated with the materials that make up the world. Ishii earned her Ph.D. in materials science from Stanford University.

Soon Dr. Ishii was working on some of the most unique materials around, those from outer space. She joined the team working on the Stardust mission, the first space probe to sample a comet and return those samples to Earth. Some of her discoveries are changing the way we see the solar system.

I love working on things that no one else has touched before,” Dr. Ishii said, “things as old as the solar system and sometimes older. The enormity of time and space are just awe-inspiring.

Subrahmanyan Chandrasekhar

Discovered the Chandrasekhar limit for neutron stars

Background:

Subrahmanyan Chandrasekhar was born in Lahore, India (now Pakistan) in 1910. His mother, who, between raising ten children, translated world literature into the Tamil language, encouraged Chandra to “do what you like.” What he liked was imagining how stars work.

Work:

Imagine a star like the Sun. It is a balancing act, with gravity pulling in, and nuclear energy pushing out. If its nuclear fuel runs out, the star collapses in on itself. What happens next?

This was the question Chandrasekhar set for himself. While traveling by train to study at Cambridge University, Chandrasekhar made the crucial discovery that would one day win him the Nobel Prize.

Chandrasekhar discovered that if the star has less than 1.4 times the mass of our Sun, at the end of its life it becomes a shrunken, hot object called a white dwarf, a star the size of a planet. If the star has more than 1.4 times the mass of our Sun, it will collapse into a neutron star, a star the size of a city. Even heavier stars will collapse into black holes, stars with no size at all. Today, the maximum mass of a stable white dwarf is known as the Chandrasekhar limit. Add any mass beyond that limit, and the white dwarf collapses into a neutron star.

The Chandra space telescope (shown in the picture), named after Chandrasekhar, looks for the X-ray signatures of neutron stars and black holes in deep space.

Any new fact or insight that I may have found has not seemed to me as a 'discovery' of mine, but rather something that had always been there and that I had chanced to pick up.

Yohannes Haile-Selassie

Paleoanthropologist, discovered Ardipithecus ramadus (Ardi)

Background:

Background: Yohannes Haile-Selassie is considered one of the greatest fossil hunters in the world, and yet he almost didn’t become a scientist. His first degree was in history, and he was assigned by the Ministry of Culture in Ethiopia to work on the conservation of historical – not prehistoric – artifacts.

Work:

Fortunately for the world of human evolution, Halie-Selassie was transferred to a fossil lab and got his first chance to work with fossil bones. He learned all he could about bone morphology. When he finally was able to search for fossils in the field, he found that he had a knack for finding bones.

“When you find you do something well,” he said, “you get more interested.” Haile-Selassie became interested enough to earn his Ph. D. His thesis work involved one of his most exciting discoveries, a five million year old human ancestor known as Ardipithecus kadabba.

Since then, Dr. Haile-Selassie has worked on one of the most famous of all pre-humans, Ardipithecus ramidus (known as Ardi), a creature filled with surprises. And surprises, of course, are what keep it fun.

“Every discovery answers some questions, but it raises many more. What we need, always, is more fossils.