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 Orbit of the Moon, orbits around Earth at Lunar distance, an average distance of (; about 30 times Earth diameter, Earth's diameter). The Moon rotation, rotates, with a rotation period (lunar ...

during the

Apollo program The Apollo program, also known as Project Apollo, was the United States human spaceflight program led by NASA, which Moon landing, landed the first humans on the Moon in 1969. Apollo followed Project Mercury that put the first Americans in sp ...

(

Apollo 11 Apollo 11 was a spaceflight conducted from July 16 to 24, 1969, by the United States and launched by NASA. It marked the first time that humans Moon landing, landed on the Moon. Commander Neil Armstrong and Lunar Module pilot Buzz Aldrin l ...

, 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 Sun's outermost atmospheric layer, the Stellar corona, corona. This Plasma (physics), plasma mostly consists of electrons, protons and alpha particles with kinetic energy betwee ...

outside the Earth's

magnetosphere In astronomy and planetary science, a magnetosphere is a region of space surrounding an astronomical object in which charged particles are affected by that object's magnetic field. It is created by a celestial body with an active interior Dynamo ...

. 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 Johannes Geiss (4 September 1926 – 30 January 2020) was a German physicist. Biography Geiss was born in 1926 in modern-day Poland, the son of farmers Hans Geiss and Irene Wilk. In 1955, he married Carmen Bach. Geiss studied physics in Götting ...

and Peter Eberhardt of the

University of Bern The University of Bern (, , ) is a public university, public research university in the Switzerland, Swiss capital of Bern. It was founded in 1834. It is regulated and financed by the canton of Bern. It is a comprehensive university offering a br ...

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: , SNF; French: , FNS; Italian: ) is a science research support organisation mandated by the Swiss Federal Government. The Swiss National Science Foundation was established under private law b ...

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

aluminum Aluminium (or aluminum in North American English) is a chemical element; it has chemical symbol, symbol Al and atomic number 13. It has a density lower than that of other common metals, about one-third that of steel. Aluminium has ...

foils (also with

platinum Platinum is a chemical element; it has Symbol (chemistry), symbol Pt and atomic number 78. It is a density, dense, malleable, ductility, ductile, highly unreactive, precious metal, precious, silverish-white transition metal. Its name origina ...

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 centre of the Solar System. It is a massive, nearly perfect sphere of hot plasma, heated to incandescence by nuclear fusion reactions in its core, radiating the energy from its surface mainly as visible light a ...

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 convent ...

types and energies of the solar wind on the lunar surface. The time exposure was 77 minutes on Apollo 11, 18 hours and 42 minutes on Apollo 12, 21 hours on Apollo 14, 41 hours and 8 minutes on Apollo 15, and 45 hours 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, and has numerous applications because it is chemically inert. The commonly known brand name of PTFE-based composition is Teflon by Chemours, a spin-off from ...

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

References

External links

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