The age of Earth is estimated to be 4.54 ± 0.05 billion years (4.54 × 109 years ± 1%). This age may represent the age of Earth's accretion, or core formation, or of the material from which Earth formed. This dating is based on evidence from radiometric age-dating of meteorite material and is consistent with the radiometric ages of the oldest-known terrestrial material and lunar samples.
Eugenie Carol Scott is an American physical anthropologist, a former university professor and educator who has been active in opposing the teaching of young Earth creationism and intelligent design in schools. She coined the term "Gish gallop" to describe a fallacious rhetorical technique of overwhelming an interlocutor with as many individually weak arguments as possible, in order to prevent rebuttal of the whole argument.
Frank Press was an American geophysicist. He was an advisor to four U.S. presidents, and later served two consecutive terms as president of the U.S. National Academy of Sciences (1981–1993). He was the author of 160 scientific papers and co-author of the textbooks Earth and Understanding Earth.
Joshua Lederberg, ForMemRS was an American molecular biologist known for his work in microbial genetics, artificial intelligence, and the United States space program. He was 33 years old when he won the 1958 Nobel Prize in Physiology or Medicine for discovering that bacteria can mate and exchange genes. He shared the prize with Edward Tatum and George Beadle, who won for their work with genetics.
Arthur Holmes was an English geologist who made two major contributions to the understanding of geology. He pioneered the use of radiometric dating of minerals, and was the first earth scientist to grasp the mechanical and thermal implications of mantle convection, which led eventually to the acceptance of plate tectonics.
Shirley Ann Mount Hufstedler was an American attorney and judge who served as the first U.S. Secretary of Education from 1979 to 1981. She previously served as a U.S. circuit judge of the U.S. Ninth Circuit Court of Appeals from 1968 to 1979.
Wolfgang Kurt Hermann "Pief" Panofsky, was a German-American physicist who won many awards including the National Medal of Science.
Allan Verne Cox was an American geophysicist. His work on dating geomagnetic reversals, with Richard Doell and Brent Dalrymple, made a major contribution to the theory of plate tectonics. Allan Cox won numerous awards, including the prestigious Vetlesen Prize, and was the president of the American Geophysical Union. He was the author of over a hundred scientific papers, and the author or editor of two books on plate tectonics. On January 27, 1987, Cox died in an apparent suicide.
Bruce Michael Alberts is an American biochemist and the Chancellor’s Leadership Chair in Biochemistry and Biophysics for Science and Education, emeritus at the University of California, San Francisco. He has done important work studying the protein complexes which enable chromosome replication when living cells divide. He is known as an original author of the "canonical, influential, and best-selling scientific textbook" Molecular Biology of the Cell, and as Editor-in-Chief of Science magazine.
Sidney David Drell was an American theoretical physicist and arms control expert.
Early Earth is loosely defined as encompassing Earth in its first one billion years, or gigayear (Ga, 109 y), from its initial formation in the young Solar System at about 4.55 Ga to some time in the Archean eon in approximately 3.5 Ga. On the geologic time scale, this comprises all of the Hadean eon, starting with the formation of the Earth about 4.6 billion years ago, and the Eoarchean, starting 4 billion years ago, and part of the Paleoarchean era, starting 3.6 billion years ago, of the Archean eon.
James Edwin Darnell Jr. is an American biologist who made significant contributions to RNA processing and cytokine signaling and is author of the cell biology textbook Molecular Cell Biology.
Francis Clark Howell, generally known as F. Clark Howell, was an American anthropologist.
Richard Doell was a distinguished American scientist known for developing the time scale for geomagnetic reversals with Allan V. Cox and Brent Dalrymple. This work was a major step in the development of plate tectonics. Doell shared the Vetlesen Prize with Cox and Dalrymple.
Leon Theodore "Lee" Silver was an American geologist who was professor of geology at the California Institute of Technology (Caltech). He was an instructor to the Apollo 13, 15, 16, and 17 astronaut crews. Working with the National Aeronautics and Space Administration (NASA), he taught astronauts how to perform field geology, essentially creating lunar field geology as a new discipline. His training is credited with a significant improvement in the J-Mission Apollo flights' scientific returns. After the Apollo program, he became a member of the United States National Academy of Sciences in 1974. He retired in 1996 as the W. M. Keck Foundation Professor for Resource Geology, emeritus, at Caltech.
David Morrison is an American astronomer, a senior scientist at the Solar System Exploration Research Virtual Institute, at NASA Ames Research Center in Mountain View, California. Morrison is the former director of the Carl Sagan Center for Study of Life in the Universe at the SETI Institute and of the NASA Lunar Science Institute. He is the past Director of Space at NASA Ames. Morrison is credited as a founder of the multi-disciplinary field of astrobiology. Morrison is best known for his work in risk assessment of near Earth objects such as asteroids and comets. Asteroid 2410 Morrison was named in his honor. Morrison is also known for his "Ask an Astrobiologist" series on NASA's website where he provides answers to questions submitted by the public. He has published 12 books and over 150 papers primarily on planetary science, astrobiology and near Earth objects.
G. Scott Hubbard is a physicist who has been engaged in space-related research as well as program, project and executive management for more than 45 years including 20 years with NASA, culminating as director of NASA's Ames Research Center. As of 2012, Hubbard chairs SpaceX Safety Advisory Panel, he previously served as the NASA representative on the Columbia Accident Investigation Board, was NASA's first Mars program director and restructured the Mars program in the wake of mission failures.
John D. Baldeschwieler is an American chemist who has made significant contributions in molecular structure and spectroscopy.
Lisa D. White is an American geologist and director of Education and Outreach at the University of California Museum of Paleontology. White is a former professor of geosciences and associate dean of the College of Science and Engineering at San Francisco State University. She was elected to the California Academy of Sciences in 2000 and as a Fellow of the Geological Society of America in 2009. White was awarded her PhD in 1989 from the University of California, Santa Cruz. In 2022 the National Center for Science Education (NCSE) presented White with the 2022 "Friend of Darwin" award.
Shelby G. Tilford was an American atmospheric spectroscopist, Earth scientist, and science program administrator. He retired in 1994 after a long career with the National Aeronautics and Space Administration, most recently serving as the Acting Associate Administrator of NASA's Office of Mission to Planet Earth. He is recognized as one of the main initiators of the Earth system science concept and NASA's Mission to Planet Earth program, which represented NASA's contribution to the U.S. Global Change Research Program (USGCRP).
