Mission to Venus Edit
Following the Eros incident, the UN needed to send a research team to Venus to study the aftermath of Eros impacting its surface. The UNN commandeered a civilian survey vessel, refitted it with sensors and probes then placed it under the command of Colonel Janus, head of UN Science Committee. Accompanying his crew was scientist Dr Michael Iturbi, a confidante of Assistant Undersecretary Avasarala.
Upon arriving at Venus, they found that Mars had also dispatched a ship to study the Eros Crater and broadcast a warning to all ships nearby to avoid them. The Arboghast attempted to get detailed scans with its complement of six probes on board. The first four probes disappeared before they were able to transmit any telemetry. The crew then tried again by lowering their altitude and launching their fifth probe, which was loaded with extra protective plating from the sixth to help it survive the descent. Although this one was successful at reaching the crater, it only broadcast video and telemetry of protomolecule structures for a few moments before dying. 
Knowing that the crater is active, Janus and Iturbi discuss what to do and decide to descend the ship into Venus's atmosphere to get a closer look. The crew prepares for the descent and deploys the ship's ballutes for atmospheric entry. Their sensors start to malfunction mid-descent before spotting that the crater itself appeared to be moving. The Martian vessel which had been observing the Arboghast's efforts followed the UNN ship into the atmosphere, descending faster and passing very close to the Arboghast. However, it disappeared from sensors soon after. Next, the Arboghast came to an abrupt stop in midair, not yet having reached the surface. The crew spotted floating blue particles from the protomolecule moving about the ship moments before the vessel completely disaggregated. All hands on board were lost.
The Arboghast was a third-generation destroyer built at Bush Shipyards thirteen years before the Ganymede incident. In that time, it had been refitted as a military science vessel. As head of the UN Science Committee, Doctor Michael-Jon de Uturbé had been aggregating telemetry data received from the Arboghast and sending it to Avasarala. When the ship is disassembled by the protomolecule, telescopes on Luna capture a video record of the event. Uturbé's analysis of the activity from the Eros crash site provides evidence to the Earth scientists that the activities are synchronized throughout the Sol system and in a way that doesn't suffer time lag constraints of electromagnetic communication.
Notes and trivia Edit
- The character Michael-Jon de Uturbé was split into two characters for the television adaptation, likely to better dramatize the opposite views of analysts.
- Michael-Jon de Uturbé is the head of the UN Science Committee in the books but Colonel Janus is the head of the UN Science Committee in the TV adaptation.
- Michael-Jon de Uturbé was responsible for making the science understandable to Avasarala but, in the TV adaptation, Colonel Janus attempt to fill that role for the politicians in the UN.
- Michael-Jon de Uturbé is the confidante of Avasarala while Michael Iturbi is her confidante in the TV adaptation. These two send Avasarala the observations and analysis from Venus data.
- Michael-Jon de Uturbé was never aboard the Arboghast. Consequently, when the ship was taken apart by the protomolecule in the book Caliban's War, Uturbé is unharmed and survives.
- Michael Iturbi and Colonel Janus are aboard the TV adaptation's Arboghast. It is apparent that the TV characters aboard Arboghast probably perished in the season 2 finale episode, "Caliban's War|Caliban's War". There is however some room for speculation that the producers allow them to survive.