flow-direction probe
31Photoconductive atomic force microscopy — (pc AFM) is a scientific technique.. Multi layer photovoltaic cells have gained popularity since mid 1980s.[1] At the time, research was primarily focused on single layer photovoltaic (PV) devices between two electrodes, in which PV properties… …
32Sun — This article is about the star. For other uses, see Sun (disambiguation). The Sun …
33technology, history of — Introduction the development over time of systematic techniques for making and doing things. The term technology, a combination of the Greek technē, “art, craft,” with logos, “word, speech,” meant in Greece a discourse on the arts, both… …
34Geology of Venus — Radar image of the surface of Venus, centered at 180 degrees east longitude Venus is a planet with striking surface characteristics. Most of what is known about its surface stems from radar observations, mainly images sent by the Magellan probe… …
35space exploration — Investigation of the universe beyond Earth s atmosphere by means of manned and unmanned spacecraft. Study of the use of rockets for spaceflight began early in the 20th century. Germany s research on rocket propulsion in the 1930s led to… …
36Corona — This article is about the astronomical term. For other uses, see Corona (disambiguation). During a total solar eclipse, the solar corona can be seen with the naked eye. A corona is a type of plasma atmosphere of the Sun or other celestial body,… …
37Geology of Mars — Mars   Mars as seen by the Hubble Space Telescope Designations …
38Earth Sciences — ▪ 2009 Introduction Geology and Geochemistry The theme of the 33rd International Geological Congress, which was held in Norway in August 2008, was “Earth System Science: Foundation for Sustainable Development.” It was attended by nearly… …
39Solar wind — For other uses, see Solar wind (disambiguation). The solar wind is a stream of charged particles ejected from the upper atmosphere of the Sun. It mostly consists of electrons and protons with energies usually between 1.5 and 10 keV. The stream of …
40Voyager 1 — This article is about the spacecraft. For the album by The Verve, see Voyager 1 (album). For fictional Voyager One from Space: 1999, see Voyager One (Space: 1999). Voyager 1 Voyager …
