Venus
Chen Chen
October 21st
10/23/13 14:21 1 10/23/13 14:21 2 Outline
Outline
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Basic information
Rotation
Atmosphere
Missions
Surface
10/23/13 14:21 3 Basic information
•  Radius 6051 km
•  Density 5.2 g/cm3
•  Orbit 0.723 AU
• 10/23/13 No14:21 moons
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Mass 0.815 MEarth
e=0.0068
i=3.39°
Day 243days
4 Rotation
Retrograde
•  Rotation of Venus is peculiar
•  Extremely slow:243 days (longer than orbital period
225 days)
•  Retrograde rotation: opposite of direction of orbit
10/23/13 14:21 5 Rotation
Moons
•  No moons
•  2002 VE68: quasi-satellite
•  2001 CK32, 2012 XE133: temporary co-orbitals
de la Fuente Marcos, C., 2013
10/23/13 14:21 6 Rotation
2012 XE133
de la Fuente Marcos, C., 2013
10/23/13 14:21 S. Mikkola et al., 2004
7 Rotation
Transit
10/23/13 14:21 8 Rotation
Transit dates
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• December 1631
• December 1639
June 1761
June 1769
• December 1874
• December 1882
June 2004
June 2012
• December 2117
• December 2125
10/23/13 14:21 9 Atmosphere
Atmosphere
•  Venus is the hottest planet, with a surface
temperature of 460°C
•  The high temperature is caused by extremely strong
greenhouse effect, thanks to the presence of a large
amount of CO2, which raises the surface temperature
by more than 400°C
•  Composition:
–  Mostly carbon dioxide: 96.5%
–  Remaining is Nitrogen: 3.5%
•  Venus has perpetual thick clouds
–  The clouds have three layers from 48 km to 68 km
–  Clouds mainly consist of droplets of
concentrated sulfuric acid (H2SO4: highly
corrosive).
10/23/13 14:21 10 Atmosphere
Evolution of Atmosphere
Early history, liquid ocean stronger radia@on from the Sun, temperature was higher greenhouse effect, higher temperature, more vapor Outgassed CO2 accumulate Hydrogen escapes into space 10/23/13 14:21 more water vapor Water vapor lost by break-­‐up of molecules runaway con@nued, oceans disappeared 11 Atmosphere
10/23/13 14:21 12 Atmosphere
10/23/13 14:21 13 Missions
Early flyby and landings
•  Flyby
–  1961 Venera 1
–  1962 Mariner 2
–  1964 Zond 1
–  1967 Mariner 5
–  1974 Mariner 10
•  Landings
–  Venera 3-10
10/23/13 14:21 14 Missions
Orbiters •  Magellan
•  Venus Express
•  Akatsuki
10/23/13 14:21 15 Missions
Recent missions
10/23/13 14:21 16 Missions
Future missions
•  Venus In-­‐Situ Explorer (VISE), to be launched in 2013. It would land and perform experiments on the surface of Venus, including taking a core sample and measuring its composi@on. •  ESA has proposed the Venus Entry Probe to be launched around the same @me. •  the Venera-­‐D spacecraX has been proposed by Roscosmos. It would be launched around 2016. 10/23/13 14:21 17 Surface
Topographic map
10/23/13 14:21 18 Surface
Surface morphology
•  Overall relatively flat:
–  70% plains
–  20% lowlands
–  10% highlands
10/23/13 14:21 19 Surface
Plains
•  80~90% of Venus surface
•  low viscous basaltic lavas
10/23/13 14:21 20 Surface
ridges
•  10% of Venus surface strongly ridged terrains
•  oldest areas on Venus
•  10-20 km between ridges
10/23/13 14:21 21 Surface
Chasmata
•  Total length of
Venus chasmata
system similar
(when adjusted
for planetary
radius) to that of
Earth’s rift
system
10/23/13 14:21 22 Surface
Coronae
•  Located along the rift zones
•  Elevated, circular structures that are pushed up from
below by rising molten rock trying to get out
10/23/13 14:21 23 Surface
up and down motions driven by molten rock welling
up from the planet's interior
10/23/13 14:21 24 Thank you for your attention
10/23/13 14:21 25