[6] During Peary's expedition in 1891–92 Astrup made friends with the local Inuit from whom he learned about survival techniques in the extreme polar environment.

Astrup accompanied Peary on a sleigh ride from their winter quarters in Inglefield Gulf and over north-western Greenland ice to Navy Cliff at Independence Fjord.

[8] Astrup wrote a series of newspaper articles and essays and gave well-attended lectures in many places in Eastern Norway.

Instead, in April 1894, Astrup and his friend Kolotengva went on a sleigh to survey the northern side of Melville Bay, with this becoming the only visible result of Peary's second expedition.

[10] Astrup's book Blandt Nordpolens naboer ("Among North Pole Neighbours"), which was published at the beginning of December 1895, deals with both of his expeditions and provides a portrait of the local Inuit.

[12] Blandt Nordpolens Naboer has many similarities with Fridtjof Nansen's book Eskimoliv from 1891, depicting the Inuit way of life, social relations and religion.

[13] Due to their geographical isolation, the polar Inuit that Astrup met had been less exposed to the European influence that had taken place further south along the western coast of Greenland, and therefore his descriptions were regarded as important among ethnographers.

[20] At Christmas 1895, Astrup travelled to Hjerkinn, and on 27 December he went alone on a ski trip to Dovre, ostensibly to meet some friends at Atna.

However, the newspapers Politiken, Dagens Nyheter and Svenska Dagbladet wrote openly that his death was considered to be suicide and not as a result of an accident which was the official explanation.

[22] Astrup helped develop techniques for exploring the polar districts, such as carrying equipment on dog sleds, combined with skiing.