George Carruthers (1939–2020)

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Obituary George Carruthers (1939–2020)

Astronomer and engineer of the first observatory on the Moon.

hen the Apollo 16 mission Carruthers’s Earth images have paved the landed on the Moon in 1972, way for global space-weather forecasting in the astronauts set up the first same way that global satellite systems are used observatory to survey the to predict surface weather. Elements of current cosmos from a celestial body. NASA missions that focus on the ionosphere WIt was designed and built by the astronomer and upper atmosphere (ICON and GOLD) can George Carruthers. By capturing light in a part be traced to Carruthers’s first global images. of the spectrum inaccessible to terrestrial tele- Carruthers continued to study the upper scopes, Carruthers’s Far Ultraviolet (FUV) lunar atmosphere and probe the structure of the camera produced the first global images of Universe. From the Skylab space station in Earth’s upper atmosphere, a region fundamen- 1973–74, his camera mapped stars, interstel- tal to communications, remote sensing and lar clouds and other objects, producing data the operation of space systems. The telescope that improved navigation, remote sensing and also peered into deep space, shining light on astronomy. From a sounding rocket in 1974, he star formation and clusters and the interstellar produced the first images of the atomic hydro- medium. Carruthers has died, aged 81. gen corona surrounding comet Kohoutek, and, As an African American, his contributions to later, similar images of comet Halley. high-profile human space-flight missions made He was instrumental in setting up the NRL’s

NASA/ZUMA WIRE Carruthers a sought-after role model for Black high-school apprenticeship programme, short scientists and engineers, as well as for those way to capture FUV spectra, amplifying diffuse courses at community centres and continuing from other communities under-represented and faintly lit objects. Like a video camera, his education for local teachers. Through Project in research and groups campaigning for equity telescope converted photons into energetic SMART, he enhanced outreach at the National in academia and industry. Carruthers was ded- electrons that were amplified and recorded Air and Space Museum and the historically icated to mentoring students in schools, com- by electron-sensitive film. The resulting Black Howard University in Washington DC. munity centres and universities. He advised compact telescope had flexible operating The legacy of Carruthers’s outreach work con- them to build wide-ranging expertise early on, configurations that mimicked the capability tinues today. NRL space scientist McArthur so that they could adapt to emerging problems of much larger systems. Jones co-chairs the task force on diversity, in research — guidance his father, a civil engi- In 1970, Carruthers’s telescope confirmed equity and inclusion set up as part of the US neer, had given him. the existence of molecular hydrogen in inter- National Science Foundation’s CEDAR (Cou- Born in 1939 in Cincinnati, Ohio, Carruthers stellar space. This discovery, which received pling, Energetics and Dynamics of Atmos- grew up in the Jim Crow era of racial-segregation international acclaim, filled a significant gap pheric Regions) programme. Others whom laws, which formally ended only in 1964, the in understanding of the interstellar medium Carruthers inspired can be found at institu- year he got his PhD. His family encouraged him and provided a framework for explaining tions from the US Air Force Research Labora- to study mathematics and science, but it was how stars form. It was then considered a step tory to universities and aerospace businesses. his own reading of science-fiction and astron- towards resolving the riddle of the Universe’s Carruthers was a man of vision. Usually omy books that awakened his fascination with ‘missing mass’. reserved, his demeanour was transformed space flight. With money he earned as a deliv- Sounding-rocket programmes permitted when he was generously sharing his wisdom ery boy, he ordered lenses and had built a tele- frequent, relatively inexpensive and short-turn- and his scientific and engineering prowess. scope from cardboard tubing by the age of ten. around opportunities to test and use sensors. He opened doors for local young people by When his father died in 1952, his mother moved Carruthers’s genius was in making very com- opening himself up to them. Of racism, he the family to Chicago, Illinois. A few years later, plex and delicate technology work flawlessly on said, “When I was their age I had no role models Carruthers built a more advanced telescope at space vehicles as they pitched, spun and shook. because nobody ever publicized them, not that the city’s Adler Planetarium. He was intensely focused on designing, building they didn’t exist ... therefore many of the minor- He tracked the progress of sounding rockets and “testing, testing, testing”. ity students didn’t know that they had a future (which follow suborbital trajectories) and the The Apollo 16 lunar camera and spectro- in science.” Carruthers worked to change that. earliest satellites, and read up on the work of graph produced global-scale images of Earth’s the Naval Research Laboratory (NRL) in Wash- upper atmosphere, including its outer ionized Angelina Callahan is a historian at the ington DC. After gaining his PhD in aeronautical layer, or ionosphere. These images revealed Naval Research Laboratory, Washington DC. and astronomical engineering at the University details about equatorial arcs of charged parti- Robert R. Meier is a professor of space of Illinois at Urbana-Champaign, he won a place cles stretching around the globe — phenomena science at George Mason University, Fairfax, on the NRL’s postdoctoral programme. under study today as the interplay between Virginia. He worked with George Carruthers So began Carruthers’s lifelong research the atmosphere and ionosphere. NRL theorists at the NRL for 50 years. David H. DeVorkin is career at the NRL. His first endeavour was and observational astronomers have used the a senior curator at the National Air and Space using a sounding rocket to search for molec- images to discover new features and confirm Museum, Washington DC. ular hydrogen in space. He devised a better earlier localized samplings. e-mail: [email protected]