Carl Edward Sagan was an American astronomer and science communicator. His best known scientific contribution is his research on the possibility of extraterrestrial life,including experimental demonstration of the production of amino acids from basic chemicals by exposure to light. He assembled the first physical messages sent into space,the Pioneer plaque and the Voyager Golden Record,which were universal messages that could potentially be understood by any extraterrestrial intelligence that might find them. He argued in favor of the hypothesis,which has since been accepted,that the high surface temperatures of Venus are the result of the greenhouse effect.
Venus is the second planet from the Sun. It is a terrestrial planet and is the closest in mass and size to its orbital neighbour Earth. Venus is notable for having the densest atmosphere of the terrestrial planets,composed mostly of carbon dioxide with a thick,global sulfuric acid cloud cover. At the surface it has a mean temperature of 737 K and a pressure of 92 times that of Earth's at sea level. These conditions are extreme enough to compress carbon dioxide into a supercritical state close to Venus's surface.
Phosphine (IUPAC name:phosphane) is a colorless,flammable,highly toxic compound with the chemical formula PH3,classed as a pnictogen hydride. Pure phosphine is odorless,but technical grade samples have a highly unpleasant odor like rotting fish,due to the presence of substituted phosphine and diphosphane (P2H4). With traces of P2H4 present,PH3 is spontaneously flammable in air (pyrophoric),burning with a luminous flame. Phosphine is a highly toxic respiratory poison,and is immediately dangerous to life or health at 50 ppm. Phosphine has a trigonal pyramidal structure.
The Summer Science Program (SSP) is an academic summer program where high school students experience college-level education and do research in celestial mechanics by studying the orbits of asteroids,biochemistry by studying the kinetic properties of enzymes,or genomics by studying antibiotic resistance. The program was established in 1959 at The Thacher School in Ojai,California. It now takes place on three astrophysics campuses,New Mexico Tech in Socorro,New Mexico,the University of North Carolina at Chapel Hill in Chapel Hill,North Carolina,and University of Colorado,Boulder in Boulder,Colorado,and two biochemistry campuses,Purdue University in West Lafayette,Indiana and Indiana University Bloomington in Bloomington,Indiana.
The Center for Astrophysics | Harvard &Smithsonian (CfA),previously known as the Harvard–Smithsonian Center for Astrophysics,is an astrophysics research institute jointly operated by the Harvard College Observatory and Smithsonian Astrophysical Observatory. Founded in 1973 and headquartered in Cambridge,Massachusetts,United States,the CfA leads a broad program of research in astronomy,astrophysics,Earth and space sciences,as well as science education. The CfA either leads or participates in the development and operations of more than fifteen ground- and space-based astronomical research observatories across the electromagnetic spectrum,including the forthcoming Giant Magellan Telescope (GMT) and the Chandra X-ray Observatory,one of NASA's Great Observatories.
Observations of the planet Venus include those in antiquity,telescopic observations,and from visiting spacecraft. Spacecraft have performed various flybys,orbits,and landings on Venus,including balloon probes that floated in the atmosphere of Venus. Study of the planet is aided by its relatively close proximity to the Earth,compared to other planets,but the surface of Venus is obscured by an atmosphere opaque to visible light.
Bryan Malcolm Gaensler is an Australian astronomer based at the University of California,Santa Cruz. He studies magnetars,supernova remnants,and magnetic fields. In 2014,he was appointed as Director of the Dunlap Institute for Astronomy &Astrophysics at the University of Toronto,after James R. Graham's departure. He was the co-chair of the Canadian 2020 Long Range Plan Committee with Pauline Barmby. In 2023,he was appointed as Dean of Physical and Biological Sciences at UC Santa Cruz.
Jay Myron Pasachoff was an American astronomer. Pasachoff was Field Memorial Professor of Astronomy at Williams College and the author of textbooks and tradebooks in astronomy,physics,mathematics,and other sciences.
The atmosphere of Venus is primarily of supercritical carbon dioxide and is much denser and hotter than that of Earth. The temperature at the surface is 740 K,and the pressure is 93 bar (1,350 psi),roughly the pressure found 900 m (3,000 ft) under water on Earth. The Venusian atmosphere supports opaque clouds of sulfuric acid,making optical Earth-based and orbital observation of the surface impossible. Information about the topography has been obtained exclusively by radar imaging. Aside from carbon dioxide,the other main component is nitrogen. Other chemical compounds are present only in trace amounts.
Sara Seager is a Canadian–American astronomer and planetary scientist. She is a professor at the Massachusetts Institute of Technology and is known for her work on extrasolar planets and their atmospheres. She is the author of two textbooks on these topics,and has been recognized for her research by Popular Science,Discover Magazine,Nature,and TIME Magazine. Seager was awarded a MacArthur Fellowship in 2013 citing her theoretical work on detecting chemical signatures on exoplanet atmospheres and developing low-cost space observatories to observe planetary transits.
The surface of Venus is dominated by volcanic features and has more volcanoes than any other planet in the Solar System. It has a surface that is 90% basalt,and about 65% of the planet consists of a mosaic of volcanic lava plains,indicating that volcanism played a major role in shaping its surface. There are more than 1,000 volcanic structures and possible periodic resurfacing of Venus by floods of lava. The planet may have had a major global resurfacing event about 500 million years ago,from what scientists can tell from the density of impact craters on the surface. Venus has an atmosphere rich in carbon dioxide,with a pressure that is 90 times that of Earth's atmosphere.
The possibility of life on Venus is a subject of interest in astrobiology due to Venus's proximity and similarities to Earth. To date,no definitive evidence has been found of past or present life there. In the early 1960s,studies conducted via spacecraft demonstrated that the current Venusian environment is extreme compared to Earth's. Studies continue to question whether life could have existed on the planet's surface before a runaway greenhouse effect took hold,and whether a relict biosphere could persist high in the modern Venusian atmosphere.
Water activity (aw) is the partial vapor pressure of water in a solution divided by the standard state partial vapor pressure of water. In the field of food science,the standard state is most often defined as pure water at the same temperature. Using this particular definition,pure distilled water has a water activity of exactly one. Water activity is the thermodynamic activity of water as solvent and the relative humidity of the surrounding air after equilibration. As temperature increases,aw typically increases,except in some products with crystalline salt or sugar.
Alicia Margarita Soderberg is an American astrophysicist whose research focused on supernovae. She was an assistant professor of astronomy at Harvard University and a postdoctoral fellow at the Harvard-Smithsonian Center for Astrophysics.
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.
Planetary oceanography,also called astro-oceanography or exo-oceanography,is the study of oceans on planets and moons other than Earth. Unlike other planetary sciences like astrobiology,astrochemistry,and planetary geology,it only began after the discovery of underground oceans in Saturn's moon Titan and Jupiter's moon Europa. This field remains speculative until further missions reach the oceans beneath the rock or ice layer of the moons. There are many theories about oceans or even ocean worlds of celestial bodies in the Solar System,from oceans made of diamond in Neptune to a gigantic ocean of liquid hydrogen that may exist underneath Jupiter's surface.
Victoria Suzanne Meadows is a Professor with the Astronomy Department and Director of the Astrobiology Program at the University of Washington. She is also the Principal Investigator for the NASA Astrobiology Institute's Virtual Planetary Laboratory Lead Team and the chair of the NAI Focus Group on Habitability and Astronomical Biosignatures (HAB). The research direction of the team is to create computer models that can be used to understand planet formation,stability and orbital evolution,and to simulate the environment and spectra of planets that can potentially be habitable.
Jane Greaves is a Professor of Astronomy based at Cardiff University. While at the University of St Andrews she led the team which discovered a protoplanet within the protoplanetary disk around the young star HL Tauri.
A number of significant scientific events occurred in 2020.
Kizzmekia "Kizzy" Shanta Corbett is an American viral immunologist. She is an Assistant Professor of Immunology and Infectious Diseases at Harvard T.H. Chan School of Public Health and the Shutzer Assistant Professor at the Harvard Radcliffe Institute since June 2021.
