Science Magazine Assignment
“Did Life come from another World,” Scientific American, Vol. 293, No.5, pp. 64-71 (November 2005) by David warmflash and Benjamin Weiss
I learned in this article that life arrived on earth from elsewhere in the cosmos, probably Mars. Living cells or their precursors arrived from space from an extraterrestrial seed. Early in its history our solar system included many worlds with liquid water. Life existed on Mars long ago. every few million years Mars undergoes an impact powerful enough to eject rocks that could eventu- ally reach Earth. if future space missions find life on the Red Planet and report that Martian biochemistry is very different from our own, researchers would know immediately that life on Earth did not come from Mars.It is not implausible that life could have arisen on Mars and then come to Earth, or the reverse. Researchers are now intently studying the transport of biological materials between planets to get a better sense of whether it ever occurred. Life also evolved on Europa, Jupiter's fourth-largest moon, Venus support(s) microbial life high in its atmosphere. Even thought Venus our nearest neighbor closer to the sun is much too hot for water to survive in a liquid state. The surface conditions on Venus were not always so harsh. Venus may have once been similar to early Earth. All life, and indeed all things, originated from the combination of tiny seeds pervading the cosmos.
The first microbes arrived from space. In the chaotic early history of the solar system, our planet was subject to intense bombardment by meteorites containing simple organic compounds. Meteorites in contrast, experience significant friction, so their surfaces typically melt during atmospheric passage. Meteorite evidence shows that material has been transferred between planets throughout the history of the solar system and that this process still occurs at a well-established rate. Furthermore,...