Day 1760

Wednesday.  Thursday.  Friday.

2009.11295

The ecological impact of high-performance computing in astrophysics

Zwart

The importance of computing in astronomy continues to increase, and so is its impact on the environment. When analyzing data or performing simulations, most researchers raise concerns about the time to reach a solution rather than its impact on the environment. Luckily, a reduced time-to-solution due to faster hardware or optimizations in the software generally also leads to a smaller carbon footprint. This is not the case when the reduced wall-clock time is achieved by overclocking the processor, or when using supercomputers. The increase in the popularity of interpreted scripting languages, and the general availability of high-performance workstations form a considerable threat to the environment. A similar concern can be raised about the trend of running single-core instead of adopting efficient many-core programming paradigms. In astronomy, computing is among the top producers of green-house gasses, surpassing telescope operations. Here I hope to raise the awareness of the environmental impact of running non-optimized code on overpowered computer hardware.

2009.11307

An astronomical institute's perspective on meeting the challenges of the climate crisis

Jahnke, et al

Analysing greenhouse gas emissions of an astronomical institute is a first step in reducing its environmental impact. Here, we break down the emissions of the Max Planck Institute for Astronomy in Heidelberg and propose measures for reductions.

2009.11344

The carbon footprint of large astronomy meetings

Burtscher, et al

The annual meeting of the European Astronomical Society took place in Lyon, France, in 2019, but in 2020 it was held online only due the COVID-19 pandemic. The carbon footprint of the virtual meeting was roughly 3,000 times smaller than the face-to-face one, providing encouragement for more ecologically minded conferencing.

2009.11779

The impact of climate change on astronomical observations

Cantalloube, et al

Climate change is affecting and will increasingly affect astronomical observations. In this paper, we investigated the role some key weather parameters play in the quality of astronomical observations, and analysed their long-term trends (longer than 30 years) in order to grasp the impact of climate change on current and future observations. In this preliminary study, we specifically analysed four parameters, the temperature, the surface layer turbulence, the wind speed at the jetstream layer and the humidity. The analyses is conducted with data from the Very Large Telescope (VLT), operated by the European Southern Observatory (ESO), located at Cerro Paranal in the Atacama desert, Chile, which is one of the driest places on Earth. To complete the data from the various sensors installed at Paranal, we used the fifth generation and 20th century European Centre Medium-Range Weather Forecasts (ECMWF) atmospheric reanalysis of the global climate, ERA5 (from 1980 to now) and ERA20C (from 1900 to 2010), which we interpolated at the Paranal observatory location. In addition, we also explored climate projections in this region, using the Coupled Model Intercomparison Project Phase 6 (CMIP6) multi-model ensemble, under the worst-case climate change Shared Socio-Economic Pathways (SSP5-8.5) scenario. Further investigation is needed to better understand the underlying mechanisms of change, as well as to assess the severity of the impact.

2009.11826

A precursor balloon mission for Venusian Astrobiology

Hein, et al

The recent 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 to ~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 outline 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 on 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 ought to permit the detection of complex organic molecules. The mission is augmented by contextual cameras that will be used to search for macroscopic signs 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 insight into the poorly understood meteorology of the middle cloud region.