Bowman spends months to the ship by yourself, slowly but surely approaching Iapetus. Through his tactic, he slowly notices a small black location on the surface area of Iapetus, and later finds it similar in shape to TMA-one, only much bigger. The experts on this planet identify this monolith "TMA-2", https://55-cash51544.liberty-blog.com/36608141/the-2-minute-rule-for-2001-cash