From the report of the First UN Martian Expedition.
"... radar and watch station established and garrisoned according to directive 25-33. Bimonthly transport service has been established between Canalopolis Settlement and Luna. Combined efforts by UNESCO and UT Armed Force personnel are being made to establish satellite stations.
"It is strongly urged by the Project Committee that more personnel be sent to Mars, however, as a serious shortage of manpower has developed due to the feverish pace of the Settlement's growth. Colonization may be the answer.
"Nowhere have the UN patrols discovered any indications of previous occupation by alien forces. Nothing resembling the invasion fleet discovered by Jan Carvel has been located. However, the cairn mentioned in the Diary has been found, further supporting the authenticity of that document...."
Addendum in manuscript.
"Higashi suggests that the message found in the Cairn confirms the original findings of the UN Psychometric Evaluation Board concerning Jan Carvel's sanity."
From the message found written in pencil on a shipping tag in the Martian Cairn built by Jan Carvel.
"Welcome, my brothers!"