Valio kirjoitti:
Suuri osa Venusta koskevista tiedoista on pelkkää arvausta.
Miten niin? Ei Venusta tutkineita luotaimia ihan yksi tai kaksi ole ollut eikä NASA ole ollut ainoa pelaaja. Esim. viimeisin ESA:n luotain on tuottanut kohtuullisen paljon uutta tietoa.
http://www.esa.int/esaMI/Venus_Express/index.htmlhttp://www.solarviews.com/eng/craft2.htm * Venera 1 - USSR Venus Flyby - 643.5 kg - (February 12, 1961)
Now in a solar orbit.
* Mariner 2 - USA Venus Flyby - 201 kg - (August 27, 1962 - January 3, 1963)
On December 14, 1962, Mariner 2 arrived at Venus at a distance of 34,800 kilometers and scanned its surface with infrared and microwave radiometers, capturing data that showed Venus's surface to be about 425°C (800°F). Three weeks after the Venus flyby Mariner 2 went off the air on January 3, 1963. It is now in a solar orbit.
* Zond 1 - USSR Venus Flyby - 890 kg - (April 2, 1964)
Communication lost en route; now in a solar orbit.
* Venera 2 - USSR Venus Flyby - 962 kg - (November 12, 1965 - 1966)
Communications failed just before arrival. Now in solar orbit.
* Venera 3 - USSR Venus Atmospheric Probe - 958 kg - (November 16, 1965 - 1966)
Communications failed just before atmosphere entry. Crashed on Venus.
* Venera 4 - USSR Venus Atmospheric Probe - 1,104 kg - (June 12, 1967)
Venera 4 arrived at Venus on October 18, 1967. This was the first probe to be placed directly into the atmosphere and to return atmospheric data. It showed that the atmosphere was 90-95% carbon dioxide. It detected no nitrogen. The surface temperature reading was 500°C and pressure reading was 75 bar. It was crushed by the pressure on Venus before it reached the surface.
* Mariner 5 - USA Venus Flyby - 244 kg - (June 14 to November, 1967)
Mariner 5 arrived at Venus on October 19, 1967, one day after Venera 4. It passed within 3,900 kilometers of the planet's surface. It studied the Venusian magnetic field and found that its atmosphere was composed of 85-99% carbon dioxide. It is now in a solar orbit.
* Venera 5 - USSR Venus Atmosphere Probe - 1,128 kg - (January 5, 1969)
Venera 5 arrived at Venus on May 16, 1969. Along with Venera 6, atmospheric data was returned indicating an atmosphere composed of 93-97% carbon dioxide, 2-5% nitrogen, and less than 4% oxygen. The probe returned data down to within 26 kilometers of surface and was then lost - crushed by the pressure on Venus.
* Venera 6 - USSR Venus Atmosphere Probe - 1,128 kg - (January 10, 1969)
Venera 6 arrived at Venus on May 17, 1969. Along with Venera 5, atmospheric data was returned indicating an atmosphere composed of 93-97% carbon dioxide, 2-5% nitrogen, and less than 4% oxygen. The probe returned data down to within 11 kilometers of surface and was then lost - crushed by the pressure on Venus.
* Venera 7 - USSR Venus Lander - 1180 kg - (August 17, 1970)
Venera 7 arrived at Venus on December 15, 1970 and was the first successful landing of a spacecraft on another planet. It used an external cooling device which allowed it to send back 23 minutes of data. The surface temperature was 475°C, and surface pressure was 90 bar.
* Venera 8 - USSR Venus Lander - 1,180 kg - (March 27, 1972)
Venera 8 arrived at Venus on July 22, 1972. It measure wind speed variations as it descended through the atmosphere: 100 meters/second above 48 kilometers, 40-47 meters/second at 42-48 kilometers, and 1 meter/second below 10 kilometers. It returned data for 50 minutes after it landed.
* Mariner 10 - USA Mercury/Venus Flyby - 526 kg - (November 3, 1973 - March 24, 1975)
Mariner 10 was the first dual planet mission. It flew past Venus on February 5, 1974 for a gravity assist to the planet Mercury. Mariner 10 was the first spacecraft to have an imaging system. It recorded circulation in the Venusian atmosphere and showed the temperature of the cloud tops to be -23°C. It is now in a solar orbit.
* Venera 9 - USSR Venus Orbiter and Lander - 4,936 kg (June 8, 1975)
Venera 9 arrived at Venus on October 22, 1975, three days before the arrival of its sister spacecraft, Venera 10. Both orbiters photographed the clouds and looked at the upper atmosphere. Differences in cloud layers were discovered at 57-70 kilometers, 52-57 kilometers and 49-52 kilometers from the surface. The lander arrived on the Venusian surface on November 22, 1975. During a period of 53 minutes, it transmitted the first black and white images of the planets surface. It showed sharp-edged flat rocks and a basaltic terrain. The probe in now in a Venus orbit.
* Venera 10 - USSR Venus Orbiter and Lander - 5,033 kg - (June 14, 1975)
Venera 10 arrived at Venus on October 25, 1975, three days after the arrival of its sister spacecraft Venera 9. Both orbiters photographed the clouds and looked at the upper atmosphere. Differences in cloud layers were discovered at 57-70 kilometers, 52-57 kilometers and 49-52 kilometers from the surface. The lander arrived on the Venusian surface on November 25, 1975. During a period of 65 minutes, it transmitted black and white images of the planets surface. The terrain was more eroded than at the Venera 9 landing site.
* Pioneer Venus 1 - USA Venus Orbiter - 582 kg - (May 20, 1978 - 1992)
Pioneer Venus 1 (also known as Pioneer 12) arrived at Venus on December 4, 1978. It operated continuously from 1978 until October 8, 1992, when contact was lost with the spacecraft. It was expected to burn up in the Venusian atmosphere 6 days later. The orbiter was the first spacecraft to use radar in mapping the planet's surface. The electron field experiment detected radio bursts presumably caused by lightening. No magnetic field was detected. From 1978 to 1988 the amount of sulfur dioxide in the atmosphere decreased by 10%. The reason for this decrease is unknown. Perhaps a large volcano erupted just before the orbiter arrived and the amount of sulfur dioxide slowly declined.
* Pioneer Venus 2 - USA Venus Atmosphere Probe - 904 kg - (August 8, 1978)
Pioneer Venus 2 (also know as Pioneer 13) carried four atmospheric probes. One large and three smaller ones. They arrived at Venus on December 9, 1978 and plunged into the atmosphere. The four probes descended through the atmosphere by parachute while the spacecraft burned up high in the atmosphere. At a height of 70-90 kilometers the probes encountered a fine haze layer. Between 10-50 kilometers there was little atmospheric convection and below 30 kilometers the atmosphere was clear.
* Venera 11 - USSR Venus Flyby/Lander - 4,940 kg - (September 9, 1978)
Venera 11 landed on Venus on December 25, 1978, and returned data for 95 minutes. The imaging systems failed.
* Venera 12 - USSR Venus Flyby/Lander - 4,940 kg - (September 14, 1978)
Venera 12 landed on December 21, 1978 and returned data for 110 minutes. Electrical discharges, probably from lightning, were recorded.
* Venera 13 - USSR Venus Flyby/Lander - 5,000 kg - (October 30, 1981)
Venera 13 landed on Venus on March 1, 1982. It returned black and white, and the first color panoramic views of the Venusian surface. It also conducted soil analysis using an x-ray fluorescence spectrometer. The sample was determined to be leucite basalt, a rare rock type on the Earth.
* Venera 14 - USSR Venus Flyby/Lander - 5,000 kg - (November 4, 1981)
Venera 14 landed on Venus on March 5, 1982. It returned black and white, and color panoramic views of the Venusian surface. It also conducted soil analysis using an x-ray fluorescence spectrometer. The sample was determined to be tholeiitic basalt similar to that found at mid-ocean ridges on the Earth.
* Venera 15 - USSR Venus Orbiter - 5,000 kg - (June 2, 1983)
Venera 15 arrived at Venus on October 10, 1983. Its high-resolution imaging system produced images at 1-2 kilometers in resolution. Venera 15 and 16 produced a map of the northern hemisphere from the pole to 30°N. They found several hot spots, possibly caused from volcanic activity.
* Venera 16 - USSR Venus Orbiter - 5,000 kg - (June 7, 1983)
Venera 16 arrived at Venus on October 14, 1983. Its high-resolution imaging system produced images at 1-2 kilometers in resolution. Venera 15 and 16 produced a map of the northern hemisphere from the pole to 30°N. They found several hot spots, possibly caused from volcanic activity.
* Vega 1 - USSR Venus/Comet Halley Flyby - 4,000 kg - (December 15, 1984)
Vega 1 flew past Venus on June 11, 1985 on its way for a flyby with comet Halley. It dropped off a Venera style lander and a balloon to investigate the Venusian middle cloud layer. The lander's soil experiment failed. The balloon floated in the atmosphere for about 48 hours at an altitude of 54 kilometers. Between Vega 1 and 2, downward gusts of 1 meter/second were encountered and wind velocities of up to 240 kilometers/hour. The Comet Halley flyby took place on March 6, 1986. The Vega 1 probe is now in a solar orbit.
* Vega 2 - USSR Venus/Comet Halley Probe - 4,000 kg - (December 21, 1984)
Vega 2 flew past Venus on June 15, 1985 on its way for a flyby with comet Halley. It dropped off a Venera style lander and a balloon to investigate the Venusian middle cloud layer. The lander's soil experiment sampled anorthosite-troctolite which is found in the lunar highlands but is rare on Earth. The balloon floated in the atmosphere for about 48 hours at an altitude of 54 kilometers. Between Vega 1 and 2, downward gusts of 1 meter/second were encountered and wind velocities of up to 240 kilometers/hour. The Comet Halley flyby took place on March 9, 1986. The Vega 2 probe is now in a solar orbit.
* Galileo - USA & Europe Jupiter Orbiter/Atmospheric Probe - 2,222 kg - (October 18, 1989)
Galileo was designed to study Jupiter's atmosphere, satellites and surrounding magnetosphere for 2 years. In order to get there, it used gravity assist techniques to pick up speed by flying past Venus on February 10, 1990. It then flew past the Earth & Moon on December 8, 1990 and then again on December 8, 1992. It has made encounters asteroid 951 Gaspra on October 29, 1991, and asteroid 243 Ida on August 28, 1993.
* Magellan - USA Venus Orbiter - 3,545 kg - (May 4, 1989 - 1994)
Magellan was released into Earth's orbit from a space shuttle and then injected into a transfer orbit to Venus by an upper stage. Its primary mission was to map Venus using synthetic aperture radar. The surface of Venus is obscured by thick clouds of carbon dioxide that makes the surface invisible to optical instruments. Magellan arrived at Venus on August 10, 1990. Its radar imaging system was able to produce images at 300 meters/pixel resolution. The spacecraft mapped 99 percent of the planet's surface. In 1994, controllers directed the orbiter into the atmosphere, where it burned up.
* Venus Express - ESA Venus Obiter - 9 November 2005