The outer solar system contains many environments of interest for studies of the origin of life. Recent observations support the idea that Jupiter and Saturn have retained the mixture of elements originally present in the solar nebula. Subsequent low temperature chemistry has produced the expected array of simple molecules giving characteristic absorption bands in the spectra of these planets. Microwave and infrared observations show that the lower atmospheres are at temperatures above 300 K. Sources of energy for non-equilibrium chemistry seem available at least on Jupiter and the presence of an array of colored materials in the Jovian cloud belts has often been cited as evidence for the existence of complex abiogenic organic molecules. Further study of both planets in an exobiological context seems well worthwhile; potentially productive methods of investigation (including planned space missions) can be described and evaluated from this point of view. Uranus and Neptune are clearly deficient in light gases, but otherwise little is known with certainty about these distant planets. Again unusually high temperatures have been reported, but not above 273 K.
Pluto and many of the outer planet satellites appear to represent a class of small bodies very unlike our neighbors in the inner solar system. Titan, Saturn's largest satellite, is especially interesting for our purposes because of its atmosphere. Methane and hydrogen are both present, and Titan's unusually reddish color again suggests the presence of organic compounds. The hydrogen-methane ratio is likely to be more similar to that of a primitive reducing terrestrial atmosphere than the ratios for Jupiter and Saturn, suggesting that in some respects this satellite may provide an even better model for early organic synthesis on the Earth. The problem of Titan's heat balance and atmospheric composition are currently under active investigation.
This is a preview of subscription content, log in to check access.
Buy single article
Instant access to the full article PDF.
Price includes VAT for USA
Subscribe to journal
Immediate online access to all issues from 2019. Subscription will auto renew annually.
This is the net price. Taxes to be calculated in checkout.
Allen, D. A. and Murdock, T. L.: 1971,Icarus 14, 1.
Armstrong, K. R., Harper, D. A., Jr., and Low, F. J.: 1972,Astrophys. J. Letters 178, L89.
Aumann, H. H., Gillespie, C. M., Jr., and Low, F. J.: 1969,Astrophys. J. Letters 157, L69.
Beer, R. and Taylor, F. W.: 1973,Astrophys. J. 179, 309.
Carr, T. D. and Gulkis, S.: 1969,Ann. Rev. Astron. Astrophys. 7, 577.
Cess, R. and Owen, T.: 1973,Nature 244, 272.
Chada, M. S., Flores, J. J., Lawless, J. G., and Ponnamperuma, C.: 1971,Icarus 15, 39.
Cruikshank, D. P. and Binder, A. B.: 1969,Astrophys. Space Sci. 3, 347.
Danielson, R. E.: 1973, private communication.
Danielson, R. E., Caldwell, J. J., and Larach, D. R.: 1973,Astrophys. J. (in press).
Encrenaz, Th., Hardorp, J., and Owen, T.: 1973, in preparation.
Gillett, F. C., Forrest, W. J., and Merrill, K. M.: 1973,Astrophys. J. Letters 184, L93.
Gillett, F. C., Low, F. J., and Stein, W. A.: 1969,Astrophys. J. 157, 925.
Gillett, F. C., Merrill, K. M., and Stein, W. A.: 1970,Astrophys. Letters 6, 247.
Greenspan, J. A. and Owen, T.: 1967,Science 156, 1489.
Gross, S.: 1973, to be published.
Gulkis, S. and Poynter, R.: 1972,Physics of the Earth and Planetary Interiors 6, 36.
Harris, D. L.: 1961, in G. P. Kuiper and B. M. Middlehurst (eds.),The Solar System, Vol. III:Planets and Satellites, U. of Chicago Press, Chicago, Chap. 8.
Johnson, T. V. and McCord, T. B.: 1970,Icarus 13, 37.
Johnson, T. V. and McCord, T. B.: 1971,Astrophys. J. 169, 589.
Joyce, R. R., Knacke, R. F., and Owen, T.: 1973,Astrophys. J. Letters 183, L31.
Kuiper, G. P.: 1944,Astrophys. J. 100, 378.
Lewis, J. S.: 1969a,Icarus 10, 393.
Lewis, J. S.: 1969b,Icarus 10, 365.
Lewis, J. S. and Prinn, R. G.: 1970,Science 169, 472.
Lewis, J. S. and Prinn, R. G.: 1973,Astrophys. J. 179, 333.
Lippincott, E. R., Eck, R., Dayhoff, M. O., and Sagan, C.: 1967,Astrophys. J. 147, 753.
Moroz, V. I.: 1967,Physics of Planets, NASA Technical Translation F-515 of ‘Fizika Planet’, Clearinghouse for Federal Scientific and Technical Information, Springfield, Va., p. 366.
Morrison, D., Cruikshank, D. P., and Murphy, R. E.: 1972,Astrophys. J. Letters 173, L143.
Münch, G. and Neugebauer, G.: 1971,Science 174, 940.
Newburn, R. L., Jr. and Gulkis, S.: 1973,Space Sci. Rev. 13, 179.
Owen, T.: 1967,Icarus 6, 138.
Owen, T.: 1969,Icarus 10, 355.
Owen, T. and Mason, H. P.: 1968,Astrophys. J. 154, 317.
Owen, T. and Mason, H. P.: 1969,J. Atmospheric Sci. 26, 870.
Pollack, J. B.: 1973,Icarus 19, 43.
Sagan, C.: 1971,Space Sci. Rev. 11, 827.
Sagan, C.: 1971,Icarus 18, 649.
Sagan, C. and Khare, B. N.: 1971,Astrophys. J. 168, 563.
Sagan, C. and Khare, B. N.: 1973, these Proceedings.
Sagan, C. and Miller, S. L.: 1960,Astron. J. 65, 499.
Sill, G.: 1972,Communications Lunar Planet. Lab., in press.
Smoluchowski, R.: 1972, in S. I. Rasool (ed.),Physics of the Solar System, NASA SP300, Washington, D.C, Chap. 8.
Trafton, L.: 1972a,Astrophys. J. 175, 285.
Trafton, L.: 1972b,Astrophys. J. 175, 295.
Urey, H. C.: 1959, in S. Fluegge (ed.),Handbuch der Physik, Springer, Berlin, Vol. 52, p. 409.
Veverka, J.: 1973,Icarus 18, 657.
Woeller, F. and Ponnamperuma, C.: 1969,Icarus 10, 386.
Zellner, B.: 1973,Icarus 18, 661.
About this article
Cite this article
Owen, T. The outer solar system: Perspectives for exobiology. Origins Life Evol Biosphere 5, 41–55 (1974). https://doi.org/10.1007/BF00927012
- Characteristic Absorption Band
- Solar Nebula
- Planet Satellite
- Outer Planet
- Large Satellite