Aldrin Next to Solar Wind Experiment - GPN-2000-001211

The Solar Wind Composition Experiment (SWC) was an experiment deployed on the

Moon The Moon is Earth's only natural satellite. It is the fifth largest satellite in the Solar System and the largest and most massive relative to its parent planet, with a diameter about one-quarter that of Earth (comparable to the width of ...

during the Apollo program (

Apollo 11 Apollo 11 (July 16–24, 1969) was the American spaceflight that first landed humans on the Moon. Commander Neil Armstrong and lunar module pilot Buzz Aldrin landed the Apollo Lunar Module ''Eagle'' on July 20, 1969, at 20:17 UTC, ...

, 12, 14, 15 and 16). The aim was to measure and sample the

solar wind The solar wind is a stream of charged particles released from the upper atmosphere of the Sun, called the corona. This plasma mostly consists of electrons, protons and alpha particles with kinetic energy between . The composition of the sol ...

outside the Earth's magnetosphere. It was the first definitive isotopic measurements of solar material.R. von Steiger, G. Gloeckler, G.M. Mason (2007). ''The Composition of Matter: Symposium honouring Johannes Geiss on the occasion of his 80th birthday'' (p. 162) The SWC was proposed and designed by a Swiss team headed by Johannes Geiss and Peter Eberhardt of the

University of Bern The University of Bern (german: Universität Bern, french: Université de Berne, la, Universitas Bernensis) is a university in the Swiss capital of Bern and was founded in 1834. It is regulated and financed by the Canton of Bern. It is a compreh ...

and Peter Signer of the Swiss Institute of Technology. It was manufactured by the

Swiss National Science Foundation The Swiss National Science Foundation (SNSF, German: ''Schweizerischer Nationalfonds zur Förderung der wissenschaftlichen Forschung'', SNF; French: ''Fonds national suisse de la recherche scientifique'', FNS; Italian: ''Fondo nazionale svizzero ...

and the University of Bern. The experiment was partially funded by the Swiss Government. The SWC experiment consisted of a 1 × 4.6-foot sheet of ultra-pure

aluminum Aluminium (aluminum in American and Canadian English) is a chemical element with the symbol Al and atomic number 13. Aluminium has a density lower than those of other common metals, at approximately one third that of steel. It ha ...

foils (also with

platinum Platinum is a chemical element with the symbol Pt and atomic number 78. It is a dense, malleable, ductile, highly unreactive, precious, silverish-white transition metal. Its name originates from Spanish , a diminutive of "silver". Pla ...

metal segments on the last Apollo 16 experiment) erected on the Moon's surface with a telescopic pole. The sheet was to be exposed to the

Sun The Sun is the star at the center of the Solar System. It is a nearly perfect ball of hot plasma, heated to incandescence by nuclear fusion reactions in its core. The Sun radiates this energy mainly as light, ultraviolet, and infrared radi ...

as to measure the

ion An ion () is an atom or molecule with a net electrical charge. The charge of an electron is considered to be negative by convention and this charge is equal and opposite to the charge of a proton, which is considered to be positive by conve ...

types and energies of the solar wind on the lunar surface. The time exposure was 77 minutes on Apollo 11, 18 h and 42 minutes on Apollo 12, 21 hours on Apollo 14, 41 hours and 8 minutes on Apollo 15, and 45 h and 5 minutes on Apollo 16. At the end of the exposure the foil was detached from the telescopic pole, placed in a

Teflon Polytetrafluoroethylene (PTFE) is a synthetic fluoropolymer of tetrafluoroethylene that has numerous applications. It is one of the best-known and widely applied PFAS. The commonly known brand name of PTFE-based composition is Teflon by Chemo ...

bag, and brought back to Earth for analysis. The experiment was successful and provided accurate Helium, He, Neon, Ne and Argon, Ar isotopic compositions of the solar wind.

References

External links

Experiment Operations During Apollo EVAs: Solar Wind Composition
{{Apollo program hardware Apollo program Apollo program hardware Lunar science Science and technology in Switzerland Solar phenomena