No abstract

No abstract

The potential detection of phosphine in the atmosphere of Venus has reignited interest in the possibility of life aloft in this environment. If the cloud decks of Venus are indeed an abode of life, it should reside in the “habitable zone” between ∼50–60 km altitude, roughly coincident with the middle cloud deck, where the temperature and pressure (but not the atmospheric composition) are similar to conditions at the Earth’s surface. We map out a precursor astrobiological mission to search for such putative lifeforms in situ with instrument balloons, which could be delivered to Venus via launch opportunities in 2022–2023. This mission would collect aerosol and dust samples by means of small balloons floating in the Venusian cloud deck and directly scrutinize whether they include any apparent biological materials and, if so, their shapes, sizes, and motility. Our balloon mission would also be equipped with a miniature mass spectrometer that should permit the detection of complex organic molecules. The mission is augmented by contextual cameras to search for macroscopic signatures of life in the Venusian atmospheric habitable zone. Finally, mass and power constraints permitting, radio interferometric determinations of the motion of the balloons in Venusian winds, together with in situ temperature and pressure measurements, will provide valuable insights into the poorly understood meteorology of the middle cloud region.

A potential second interstellar object C/2019 Q4 (Borisov) was discovered after the first known interstellar object 1I/'Oumuamua. Can we send a spacecraft to this object, using existing technologies? In this paper, we assess the technical feasibility of a mission to C/2019 Q4 (Borisov), using existing technologies. We apply the Optimum Interplanetary Trajectory Software (OITS) tool to generate trajectories to C/2019 Q4 (Borisov). As results, we get the minimal DeltaV trajectory with a launch date in July 2018. For this trajectory, a Falcon Heavy launcher could have hauled a 2 ton spacecraft to C/2019 Q4 (Borisov). For a later launch date, results for a combined powered Jupiter flyby with a Solar Oberth maneuver are presented. For a launch in 2030, we could reach C/2019 Q4 (Borisov) in 2045, using the Space Launch System, up-scaled Parker probe heatshield technology, and solid propulsion engines. A CubeSat-class spacecraft with a mass of 3 kg could be sent to C/2019 Q4 (Borisov). If C/2019 Q4 (Borisov) turns out to be indeed an interstellar object, its discovery shortly after the discovery of 1I/'Oumuamua implies that the next interstellar object might be discovered in the near future. The feasibility of a mission to both, 1I/'Oumuamua and C/2019 Q4 (Borisov) using existing technologies indicates that missions to further interstellar objects are likely to be feasible as well.