Did primitive cells come from space? F. A. Jones 01.30.01 Scientists working at the University of Santa Cruz report that they have created cell-like membranes from simple molecules in chemical reactions conducted under harsh conditions, just like those found in interstellar space. These scientists used simple chemicals in an environment that resembled space – little heat, no air, and a lot of radiation. They found that under these conditions, simple membranes that look like cells can form on their own.    The simple membranes, called vesicles, are semi-permeable to certain chemicals. All living cells are composed of semipermeable membranes. Semi-permeable membranes allow small molecules (like water and oxygen) to move in and out of the vesicle, but prevent larger molecules (like proteins and DNA) from moving across the barrier.    Although artificial membranes have been created under laboratory conditions before, this is the first experiment that shows that it may have been possible for these molecules to have formed in space.     The building blocks of life may have truly rained from the skies. One of the theories about the origin of life on Earth holds that simple organic molecules necessary for life were transported to the young Earth by meteors or asteroids. Organic molecules and water, also necessary for life, have been detected in the tails of comets, like the one pictured above. This new evidence suggests that simple cell-like material might have arrived on Earth from space.    The scientists hope that their discoveries will lead to insights on the conditions that may have lead to the formation of life on Earth over 4 billion years ago.  Jason P. Dworkin, et al. 2001. Self-assembling amphiphilic molecules: Synthesis in simulated interstellar/precometary ices. Proceedings of the National Academy of Sciences 98: 815-819.    Photo: NASA ©2001 The Aurora Collection, Inc. All Rights Reserved. Site Development by: Interactive Multimedia. Inc.