Smithsonian Astrophysical Observatory
The Smithsonian Astrophysical Observatory, founded in 1890, is a research center of the Smithsonian Institution. In 1955, the observatory moved to Cambridge, Massachusetts, and became affiliated with the Harvard College Observatory. In that era, the observatory created the world’s first satellite-tracking network, establishing the organization as a pioneer in space science research. In 1973, the Smithsonian and Harvard created the joint Center for Astrophysics | Harvard & Smithsonian.
Staff—The Center for Astrophysics | Harvard & Smithsonian comprised more than 850 people in 2024—some 200 with a Harvard affiliation and approximately 650 with a Smithsonian affiliation, including SAO staff scientists, engineers, technical staff, administrators and educators, as well as visiting scientists, postdoctoral fellows and graduate students.
Key Areas of Research at the Center
Exoplanets—In the past three decades, astronomers have detected more than 5,000 planets in over 4,000 planetary systems outside Earth’s solar system. SAO scientists use ground-based and space-based instruments to detect and characterize these exoplanets. SAO has a major role in NASA’s TESS mission to search for habitable Earth-like planets and in using NASA’s JWST mission to search for signs of life in exoplanet atmospheres.
The Sun and Solar Weather—SAO scientists study the sun to learn about its day-to-day behavior, which includes giant magnetic storms that eject high-energy particles into the solar system. The observatory also has developed computer models that may one day help forecast these storms and warn astronauts.
Star and Planet Formation—To learn how stars form, SAO scientists study the structure of dark cosmic clouds and the young stars within the clouds. To study the birth of planets, SAO scientists examine the structure of disks of matter and other formations associated with the youngest stars.
The Extreme Universe—The universe contains strange objects and explosions that dwarf anything that can be produced in an Earth-bound laboratory. SAO scientists measure many different types of radiation, from radio waves to X-rays, to study objects such as black holes, pulsars, supernovae, white dwarfs, neutron stars and magnetars.
Asteroids and Comets—When the planets in the solar system formed, the “leftovers” from this cosmic construction process became comets and asteroids. SAO studies these objects to understand the formation of the solar system. Also, SAO’s Minor Planet Center collects observations of asteroids and comets from telescopes and satellites around the world to calculate their orbits and watch for objects that could potentially impact Earth.
Space-based Observatories
SAO has contributed to the development and operation of many observatories around the world, observing cosmic objects and events by detecting radiation across the electromagnetic spectrum, from low-energy radio submillimeter and X-ray waves, to light waves and high-energy gamma rays.
Chandra X-ray Observatory—NASA’s Chandra X-ray Observatory, operated by SAO, is the most sophisticated X-ray observatory ever built, providing images 25-times sharper than previous pictures. When launched in 1999, Chandra joined the Hubble Space Telescope as one of NASA’s “Great Observatories.” Chandra observes X-rays from high-energy processes taking place throughout the universe, allowing more detailed studies of black holes, supernovae and dark matter.
Solar Dynamics Observatory—The Solar Dynamics Observatory is a NASA mission that has been observing the sun since 2010. The SDO carries the Atmospheric Imaging Assembly, an instrument that SAO helped design and build with Lockheed-Martin, that takes photos of the full sun every 12 seconds with in super-high resolution.
Parker Solar Probe—NASA’s Parker Solar Probe was launched in 2018 to observe the outer atmosphere of the sun by directly flying to within less than 7 million kilometers of the sun’s center, closer than any other satellite has achieved. SAO scientists built an instrument for the probe that helps assess the structure and dynamics of the energy flow that heats the uppermost portion of the sun’s atmosphere and drives solar wind.
Ground-based Observatories
Submillimeter Array—The submillimeter array in Mauna Kea, Hawaii, the first of its kind in the world, was dedicated in November 2003. The SMA is designed to study star and galaxy formation, and it is a critical element of the Event Horizon Telescope, a global network of telescopes whose primary goals include producing the first images of supermassive black holes.
Fred Lawrence Whipple Observatory—Located 35 miles south of Tucson, Arizona the Fred Lawrence Whipple Observatory is SAO’s largest field station. The observatory’s facilities include several large telescopes, as well as several arrays of smaller telescopes primarily dedicated to planet hunting.
MMT Observatory—The MMT is a 6.5-meter-diameter telescope located at the Whipple Observatory can analyze light from hundreds of objects at once using instruments built by SAO.
Greenland Telescope—This telescope is located at Thule Space Base in Greenland, located 750 miles north of the arctic circle, and it began operations in December 2017. It is designed to detect radio waves from stars, star-forming regions, galaxies and the vicinity of black holes. Its extreme location enhances the capabilities of the EHT.
South Pole Telescope—This telescope is designed to conduct large-area surveys of faint, low-contrast emissions at the millimeter and submillimeter wavelengths, such as those emitted from the Big Bang. This telescope will help scientists learn about the mysterious dark-energy phenomenon that is speeding up the expansion of the universe. It is also a key component of the Event Horizon Telescope project.
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SI-78-2024
