Silver chlorideSilver chloride is a chemical compound with the chemical formula AgCl. This white crystalline solid is well known for its low solubility in water and its sensitivity to light. Upon illumination or heating, silver chloride converts to silver (and chlorine), which is signaled by grey to black or purplish coloration in some samples. AgCl occurs naturally as a mineral chlorargyrite. It is produced by a metathesis reaction for use in photography and in pH meters as electrodes.
Scanning probe microscopyScanning probe microscopy (SPM) is a branch of microscopy that forms images of surfaces using a physical probe that scans the specimen. SPM was founded in 1981, with the invention of the scanning tunneling microscope, an instrument for imaging surfaces at the atomic level. The first successful scanning tunneling microscope experiment was done by Gerd Binnig and Heinrich Rohrer. The key to their success was using a feedback loop to regulate gap distance between the sample and the probe.
MicroelectrodeA microelectrode is an electrode used in electrophysiology either for recording neural signals or for the electrical stimulation of nervous tissue (they were first developed by Ida Hyde in 1921). Pulled glass pipettes with tip diameters of 0.5 μm or less are usually filled with 3 molars potassium chloride solution as the electrical conductor. When the tip penetrates a cell membrane the lipids in the membrane seal onto the glass, providing an excellent electrical connection between the tip and the interior of the cell, which is apparent because the microelectrode becomes electrically negative compared to the extracellular solution.
Luna 16Luna 16 was an uncrewed 1970 space mission, part of the Soviet Luna program. It was the first robotic probe to land on the Moon and return a sample of lunar soil to Earth. The 101 grams (3.56 ounces) sample was returned from Mare Fecunditatis. It represented the first successful lunar sample return mission by the Soviet Union and was the third lunar sample return mission overall. The spacecraft consisted of two attached stages, an ascent stage mounted on top of a descent stage.
Soviet space programThe Soviet space program (Kosmicheskaya programma SSSR) was the national space program of the former Union of Soviet Socialist Republics (USSR), active from 1955 until the dissolution of the Soviet Union in 1991. Soviet investigations in rocketry began with the formation of a research laboratory in 1921, but these efforts were hampered by the devastating war with Germany.
Luna programmeThe Luna programme (from the Russian word Луна "Luna" meaning "Moon"), occasionally called Lunik by western media, is a series of robotic spacecraft missions sent to the Moon by the Soviet Union and later Russia between 1959 and 2023. Fifteen were successful, each designed as either an orbiter or lander, and accomplished many firsts in space exploration. They also performed many experiments, studying the Moon's chemical composition, gravity, temperature, and radiation.
