| Dictionary, Encyclopedia and Thesaurus - The Free Dictionary 1,803,721,991 visitors served. |
|
Dictionary/ thesaurus | Medical dictionary | Legal dictionary | Financial dictionary | Acronyms | Idioms | Encyclopedia | Wikipedia encyclopedia | ? |
Venera |
Also found in: Wikipedia, Hutchinson | 0.01 sec. |
VeneraAny of a series of unmanned Soviet planetary probes sent to Venus 1965–83. Venera 2 flew to within 25,000 mi (40,000 km) of Venus in 1966; a few days later, Venera 3 crash-landed on its surface, becoming the first spacecraft to strike another planet. Later missions analyzed Venus's atmosphere, made soft landings, detected certain long-lived radioactive isotopes (chiefly uranium and thorium), sent back the first close-up photographs of the planet's surface, and mapped the surface of the northern hemisphere with radar (by Venera 15 and 16, the last two of the series). How to thank TFD for its existence? Tell a friend about us, add a link to this page, add the site to iGoogle, or visit webmaster's page for free fun content. |
|
| ? Mentioned in | ? References in periodicals archive | |
|---|---|---|
He based his tentative dating on the planet's hot temperatures and two chemical studies: measurements of sulfur dioxide in the Venusian atmosphere -- an indicator of volcanic activity -- made in 1982 by the Pioneer-Venus spacecraft, and soil surface analyses by Venera 15 and 16, two Soviet craft that landed on the planet in 1984. The only previous measurement was done by the Russian Venera 9/10 orbiters in 1975, with a spectral resolution 100 times inferior to that of Keck-HIRES. Pioneer Venus, mostly in 1979; by the Soviet Venera 15 and 16 craft in 1983; and by Earth-based instruments. |
| Encyclopedia |
| Free Tools: |
For surfers:
Free toolbar & extensions |
Word of the Day |
Help
For webmasters: Free content | Linking | Lookup box | Double-click lookup | Partner with us |
|---|