Posted on 03/12/2002 9:21:21 PM PST by petuniasevan
Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
Explanation: What could cause a huge cylindrical mountain to rise from the surface of Venus? Such features that occur on Venus are known as coronas. Pictured above in the foreground is 500-kilometer wide Atete Corona found in a region of Venus known as the Galindo. The image was created by combining multiple radar maps of the region to form a computer-generated three-dimensional perspective. The series of dark rectangles that crosses the image from top to bottom were created by the imaging procedure and are not real. The origin of massive coronas remains a mystery although speculation holds they result from some form of volcanism. Studying Venusian coronas help scientists better understand the inner structure of both Venus and Earth.
Venus - one place I can't see manned exploration EVER occurring.
Mass (kg)............................................4.87 x 10^24
Diameter (km)........................................12104
Mean density (kg/m^3) ...............................5250
Escape velocity (m/sec)..............................10400
Average distance from Sun (AU).......................0.723
Rotation period (length of day in Earth days)........243.0 (retrograde)
Revolution period (length of year in Earth days).....224.7
Obliquity (tilt of axis degrees).....................178
Orbit inclination (degrees)..........................3.39
Orbit eccentricity (deviation from circular).........0.007
Mean surface temperature (K).........................726
Surface pressure.................................90 bars (Earth sea level = 1 bar)
Visual geometric albedo (reflectivity)...............0.59
Highest point on surface.............................Maxwell Montes (17 km above mean planetary radius)
Atmospheric components...............................96% carbon dioxide, 3% nitrogen, 0.003% water vapor
Surface materials....................................basaltic rock and altered materials
Compare that to Earth:
Mass (kg)............................................5.98 x 10^24 Diameter (km)........................................12756 Mean density (kg/m^3) ...............................5520 Escape velocity (m/sec)..............................11200
Average distance from Sun (AU).......................1
Rotation period (length of day in Earth hours).......23.93
Revolution period (length of year in Earth days).....365.26
Obliquity (tilt of axis in degrees)..................23.4
Orbit inclination (degrees)..........................0
Orbit eccentricity (deviation from circular).........0.017
Mean surface temperature (K).........................281
Maximum surface temperature (K)......................310
Minimum surface temperature (K)......................260
Visual geometric albedo (reflectivity)...............0.39
Highest point on surface.............................Mount Everest (over 8 km above sea-level)
Atmospheric components...............................78% nitrogen, 21% oxygen, 1% argon
Surface materials....................................basaltic and granitic rock and altered materials
And here I was, thinking that the rectangles were zipper marks that resulted when they joined two photos together. ;-)
Seriously, though, the image is intriguing and it's always fun to see something from that website. Thanks for sharing.
Glad you like the images. I'll certainly try to get them posted daily.
Yeah, sure. I can tell a Firestone FX-150-30 tire track when I see one. (j/k) :-)
After launch and a four month cruise to Venus, the descent vehicle separated from the bus and plunged into the Venus atmosphere on 1 March 1982. After entering the atmosphere a parachute was deployed. At an altitude of 47 km the parachute was released and simple airbraking was used the rest of the way to the surface. Venera 13 landed about 950 km northeast of Venera 14 at 7 deg 30 min S, 303 E, just east of the eastern extension of an elevated region known as Phoebe Regio. The area was composed of bedrock outcrops surrounded by dark, fine-grained soil. After landing an imaging panorama was started and a mechanical drilling arm reached to the surface and obtained a sample, which was deposited in a hermetically sealed chamber, maintained at 30 degrees C and a pressure of about .05 atmospheres. The composition of the sample determined by the X-ray flourescence spectrometer put it in the class of weakly differentiated melanocratic alkaline gabbroids. The lander survived for 127 minutes (the planned design life was 32 minutes) in an environment with a temperature of 457 degrees C and a pressure of 84 Earth atmospheres. The descent vehicle transmitted data to the bus, which acted as a data relay as it flew by Venus.
Not only are we talking surface temps of around 900 degrees F, and atmospheric pressures of 90 times Earth sea level pressure, but also a strongly acidic environment.
Here's an image from one lander.
Venera 9 Lander image of the surface of Venus at about 32 S, 291 E. The Lander touched down at 5:13 UT with the sun near zenith on 22 October 1975 and operated for 53 minutes, allowing return of this single image. The white object at the bottom of the image is part of the lander. The distortion is caused by the Venera imaging system. Angular and partly weathered rocks, about 30 to 40 cm across, dominate the landscape, many partly buried in soil. The horizon is visible in the upper left and right corners. (Venera 9 Lander, surface image)
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