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Top Document: [sci.astro] ET Life (Astronomy Frequently Asked Questions) (6/9) Previous Document: F.02 Life in the Solar System Next Document: F.02.2 Is there life in Jupiter (or Saturn)? See reader questions & answers on this topic! - Help others by sharing your knowledge The Viking landers found conditions on the surface of Mars unlikely to support life as we know it. The mass spectrometer found too little carbon, which is the basis for organic molecules. The chemistry is apparently highly oxidizing as well. Some optimists have nevertheless argued that there still might be life on Mars, either below the surface or in surface regions not sampled by the landers, but most scientists consider life on Mars quite unlikely. Evidence of surface water suggests, however, that Mars had a wetter and possibly warmer climate in the past, and life might have existed then. If so, there might still be remnants (either living or fossil) today, but close examination will be necessary to find out. More recently, McKay et al. have invoked biological activity to explain a number of features detected in a meteorite from Mars. See <URL:http://www.fas.org/mars/> for additional information. User Contributions:Comment about this article, ask questions, or add new information about this topic:Top Document: [sci.astro] ET Life (Astronomy Frequently Asked Questions) (6/9) Previous Document: F.02 Life in the Solar System Next Document: F.02.2 Is there life in Jupiter (or Saturn)? Part0 - Part1 - Part2 - Part3 - Part4 - Part5 - Part6 - Part7 - Part8 - Single Page [ Usenet FAQs | Web FAQs | Documents | RFC Index ] Send corrections/additions to the FAQ Maintainer: jlazio@patriot.net
Last Update March 27 2014 @ 02:11 PM
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with stars, then every direction you looked would eventually end on
the surface of a star, and the whole sky would be as bright as the
surface of the Sun.
Why would anyone assume this? Certainly, we have directions where we look that are dark because something that does not emit light (is not a star) is between us and the light. A close example is in our own solar system. When we look at the Sun (a star) during a solar eclipse the Moon blocks the light. When we look at the inner planets of our solar system (Mercury and Venus) as they pass between us and the Sun, do we not get the same effect, i.e. in the direction of the planet we see no light from the Sun? Those planets simply look like dark spots on the Sun.
Olbers' paradox seems to assume that only stars exist in the universe, but what about the planets? Aren't there more planets than stars, thus more obstructions to light than sources of light?
What may be more interesting is why can we see certain stars seemingly continuously. Are there no planets or other obstructions between them and us? Or is the twinkle in stars just caused by the movement of obstructions across the path of light between the stars and us? I was always told the twinkle defines a star while the steady light reflected by our planets defines a planet. Is that because the planets of our solar system don't have the obstructions between Earth and them to cause a twinkle effect?
9-14-2024 KP