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Florence Ray Moulton

About Florence Ray Moulton

American astronomer known for being a believer of the Chamberlin-Moulton planetesimal hypothesis, which says planets formed from smaller parts.

Early life

He finished his graduate studies at the University of Chicago, receiving a Ph.D. in 1899.


The moon crater Moulton is named in his honor.

Family of Florence Ray Moulton

He was born and raised in Le Roy, Michigan.

Close associates of Florence Ray Moulton

He and Edwin Hubble were both famous American astronomers.

Henrietta Leavitt

About Henrietta Leavitt

Astronomer who helped measure the relative brightness of Cepheid variables, which helped scientists to measure distances to stars. After her death her work was used to determine that the Milky Way is not the only galaxy in the observable universe.

Early life

After her education, she worked at Harvard College Observatory calculating and recording the brightness of stars.


Her observation of a class of stars that pulse brighter and darker made possible the calculation of much greater interstellar distances with more accuracy than ever before.

Family of Henrietta Leavitt

She was born in Lancaster, Massachusetts, the daughter of George Roswell Leavitt, a Congregational church minister.

Close associates of Henrietta Leavitt

Based on her work, Edwin Hubble was able to calculate that the universe is expanding.

Gerry Neugebauer

About Gerry Neugebauer

American astronomer known for his work within the field of infrared astronomy. He s won two NASA Exceptional Scientific Achievement medals and he has been elected to the National Academy of the Sciences, the American Philosophical Society, the American Academy of Arts and Sciences and the Royal Astronomical Society.

Early life

He immigrated to the U.S. when he was 7.


He had a major role in the design and construction of the W. M. Keck Observatory in Hawaii.

Family of Gerry Neugebauer

He was the son of Otto Neugebauer, an Austrian mathematician.

Close associates of Gerry Neugebauer

Like Albert Einstein before him he received a Royal Astronomical Society medal.

Annie Jump Cannon

About Annie Jump Cannon

American astronomer who greatly impacted contemporary stellar classification when she created the Harvard Classification Scheme with Edward C. Pickering. She was the first woman elected as an officer of the American Astronomical Society.

Early life

She battled scarlet fever while a student at Wellesley College, leaving her mostly deaf.


She classified 230,000 stellar bodies, which earned her the nickname of “Census Taker of the Sky.”

Family of Annie Jump Cannon

Her father, Wilson Lee Cannon, was a shipbuilder and state senator.

Close associates of Annie Jump Cannon

She was among many famous Wellesley College alumnae, a list that would later include Hillary Rodham Clinton.

Carl Sagan

About Carl Sagan

Astronomer whose love of space inspired readers and TV viewers to look to the stars. He is best known for co-writing and narrating the award-winning 1980 television series Cosmos: A Personal Voyage.

Early life

He grew up with a strong desire to learn and was fascinated by dinosaurs and stars as a boy.


He wrote the novel Contact, which was adapted into a film in 1997 with Matthew McConaughey, James Woods, and Jodie Foster.

Family of Carl Sagan

He married his third wife, Ann Druyan, in 1981.

Close associates of Carl Sagan

Neil deGrasse Tyson hosted 2014 s Cosmos: A Spacetime Odyssey, a follow-up to Sagan s Cosmos.

Nancy Grace Roman

About Nancy Grace Roman

Executive NASA astronomer who discovered that stars made of helium and hydrogen moved faster than other stars. She received the Federal Woman s Award in 1962.

Early life

She started an astronomy club that met once a week when she was eleven.


After working for NASA for 21 years, she worked to help the Goddard Space Flight Center until 1997.

Family of Nancy Grace Roman

She was born to geophysicist Irwin Roman and music teacher Georgia Smith Roman.

Close associates of Nancy Grace Roman

Her group worked on the Hubble Telescope, which was named after Edwin Hubble.