This is an image of Venus.
Click on image for full size
Like Mars, there is no plate tectonics on the surface of Venus. The surface of Venus does not *seem* to have changed or moved in billions of years. Unlike the case of Mars, however, careful examination of the evidence supports the idea that the surface of Venus may be active in a way that is very different from the Earth.
- 1.) An examination of the surface of Venus shows cratering at all latitudes and longitudes. Craters are wiped out when the surface of a planet moves. Heavy cratering stopped soon after the solar system formed, about 4 billion years ago, so a surface which still shows evidence of that catering has not changed in a very long time.
- 2.) Although heavy cratering has stopped, some cratering continues to this day. The impact of the SL-9 comet shows that planets can still be hit by objects in space. The cratering record of Venus is *very* peculiar in that
- all surfaces are evenly cratered
- the cratering rate is roughly the same as that of the Earth at present.
- 3.) Features which suggest a lithosphere in motion are present, but few on Venus.
The surface of the Earth changes rapidly, so evidence of terrestrial cratering rapidly disappears. Nevertheless, because not every land mass undergoes subduction, there are regions of the Earth's surface that are nearly 4 Billion Years old. The case may not be the same on Venus. This evidence suggests an age for the entire surface of Venus of not more than 500 million years!
This evidence suggests that Venus has a completely different cooling history than that of the Earth, and the entire surface is forced to change every few hundred million years or so.
You might also be interested in:
What types of instructional experiences help K-8 students learn science with understanding? What do science educators teachers, teacher leaders, science specialists, professional development staff, curriculum designers, school administrators need to know to create and support such experiences?...more
Unlike Earth, there is no plate tectonics on Mars. The Martian surface does not seem to have changed or moved in billions of years. The evidence for this fact can be found in two ways. 1.) An examination...more
This is a map of the surface of Venus (turned sideways!). Lowlands in the map are similar to an ocean bottom, and highlands resemble continents. As can be seen in the image, the surface of Venus consists...more
Over the course of time there are many things which can cause the surface of a planet to change its appearance. winds can slowly wear erode a planet's surface. The surface of Mars is affected by wind....more
The pieces of Comet Shoemaker-Levy 9 received names! However not all of the segments were detected, and some sections broke apart into two or more pieces after the original piece had been named. These...more
This is an example of the cratered terrain on Venus. Venusian craters are a little unusual in that there is a large amount of impact melt around the crater. This means either that the temperature of the...more
Let's look at the evidence: Mercury Venus The Moon Mars Io Europa Ganymede Callisto Triton Miranda What about Jupiter, Saturn, Uranus, Neptune, Titan, or Pluto? These planets or moons either have no surface,...more
The terrestrial planets formed by accretion of rocky material and volatiles out of the primitive solar nebula. As they finished forming, about 4 Billion Years ago, the surface continued to be bombarded...more