ABSTRACT
The rapid and spectacular advances in rocketry which, as we have already seen, have led to a tremendous increase in our knowledge of conditions on the lunar surface, have similarly yielded vital information about the two nearer planets — Venus and Mars — and without doubt the next decade will extend this knowledge even further. At the present time, serious consideration is being given to the sending out of unmanned probes into the depths of the solar system to obtain close-up pictures of the outer planets, possibly even as far afield as distant Pluto.
