Avalanche And Volcano

"The glacier shuddered. The ridge cracked asunder and fell in shards. The area on which the humans stood split free and toppled into the bowl. An avalanche poured after."
-Poul Anderson, "The Saturn Game" IN Anderson, The Van Rijn Method (Riverdale, NY, 2009), pp. 1-73 AT p. 37.

How often in Poul Anderson's works does a sudden change in an alien environment endanger the life of a space explorer? Anderson's point is that explorers encounter the unknown. In fact, the man trying to rescue the three caught in the avalanche has a similar experience:

"A white volcano erupted. The outburst engulfed him. Suddenly he was flying blind... Without exterior vision to aid him, he sent the vessel tumbling end over end."
-op. cit., p. 52.

And, to draw the moral for us:

"No reasonable person will blame any interplanetary explorer for miscalculations about the actual environment, especially when some decision had to be made, in haste and under stress. Occasional errors are inevitable. If we knew exactly hat to expect throughout the Solar System, we would have no reason to explore it."
-ibid., p. 50.

An earlier warning:

"'That's a new world we're about to touch down on - tiny, but a world, and strange in ways we can't guess... We can't rely on meters and cameras alone. We've got to use our eyes and brains.'"
-ibid., p. 5.

One detail has been learned from Armstrong's and Aldrin's experience in Lunar gravity:

"Walker? No, leaper. The three bounded exultant, little hindered by spacesuits, life support units, tool and ration packs."
-op. cit., p. 16.

But their exultation will not last.