Article | Published:

A soft X-ray image of the Moon


A soft X-ray image of the Moon obtained by the Röntgen Observatory Satellite ROSAT clearly shows a sunlit crescent, demonstrating that the Moon's X-ray luminosity arises from backscattering of solar X-rays. The Moon's optically dark side is also X-ray dark, and casts a distinct shadow on the diffuse cosmic X-ray background. Unexpectedly, the dark side seems to emit X-rays at a level about one per cent of that of the bright side; this emission very probably results from energetic solar-wind electrons striking the Moon's surface.

Access optionsAccess options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.


  1. 1

    Giacconi, R., Gursky, H., Paolini, F. R. & Rossi, B. B. Phys. Rev. Lett. 9, 439–443 (1962).

  2. 2

    Gorenstein, P., Golub, L. & Bjorgholm, P. Moon 9, 129–140 (1974).

  3. 3

    Pfeffermann, E. et al. Society of Photooptical Instrumentation Engineers 733, 519–532 (1986).

  4. 4

    Trümper, J. et al. Nature 349, 579–583 (1991).

  5. 5

    Trümper, J. Adv. Space Res. 2 (4), 241–249 (1983).

  6. 6

    Kopal, Z. Geophys. Astrophys. Monogr. Vol. 7 (Reidel, Dordrecht, 1974).

  7. 7

    Chandrasekhar, S. Radiative Transfer (Dover, New York, 1960).

  8. 8

    Kopal, Z. Geophys. Astrophys. Monogr. Vol. 4 (Reidel, Dordrecht, 1966).

  9. 9

    Haymes, R. C. & Juday, R. D. Planet. Space Sci. 13, 1249–1254 (1965).

  10. 10

    Pilipp, W. G. et al. J. geophys. Res. 92, 1075–1101 (1987).

  11. 11

    Neff, N. F. in Solar Terrestrial Physics Part II (ed. Dyer, E. R.) 159–205 (Reidel, Dordrecht, 1972).

  12. 12

    Evans, R. D. The Atomic Nucleus (McGraw-Hill, New York, 1955).

Download references

Author information

Rights and permissions

Reprints and Permissions

About this article

Further reading


By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.