The Soviet Deputy Premier, Mr. Anastas Mikoyan, is reported to have stated recently that Russia has a missile ready to “visit the Sun.“

The Russians have been achieving a notable series of “firsts” in space exploration, and this statement may have led some to speculate on whether they will be the first to reach the Sun.

It is, of course, strictly impossible to talk in terms of hitting or reaching the Sun, as it has no solid surface. Indeed the streams of matter and radiation it emits travel out into space beyond the orbit of our planet. However, for practical purposes the Sun is opaque over a diameter of just under a million miles, and this constitutes a generally agreed boundary for purposes of such a study as this.

Conditions on the bodies that constitute the Solar system are dominated by the Sun, and this alone would justify the continued examination of its behaviour. Additional justification is provided by the fundamental knowledge of matter obtained through observing the Sun and its radiated energy.