References [9] NASA - LUVOIR, Large UV/Optical/IR Sur- veyor. https://asd.gsfc.nasa.gov/luvoir/, [1] NASA - Catalog of Earth Satellite Or- . bits. https://earthobservatory.nasa.gov/ [10] M. Cropper. The Polars. , 54:195–295, De- features/OrbitsCatalog. cember 1990. doi: 10.1007/BF00177799. [2] Nadia Drake - Will Elon Musk‘s Starlink [11] NASA - Introduction to Cataclysmic Varibles satellites harm astronomy? Here‘s what we (CVs). https://heasarc.gsfc.nasa.gov/ know. docs/objects/cvs/cvstext.html,. [3] M. B. Sweatman and A. Coombs. Decoding [12] Black hole image makes history; nasa tele- european palaeolithic art: Extremely ancient scopes coordinated observations. https: knowledge of precession of the equinoxes. //www.nasa.gov/mission_pages/chandra/ arXiv preprint arXiv:1806.00046, 2018. news/black-hole-image-makes-history,. [4] NASA Exoplanet Exploration - Planets [13] Event Horizon Telescope Collaboration, Outside Our Solar System. https:// Kazunori Akiyama, Antxon Alberdi, Wal- exoplanets.nasa.gov,. ter Alef, Keiichi Asada, Rebecca Azulay, [5] NASA - ESO Discovers Earth-Size Planet Anne-Kathrin Baczko, David Ball, Mis- in Habitable Zone of Nearest Star. lav Baloković, and John Barrett. First https://www.nasa.gov/feature/jpl/ M87 Event Horizon Telescope Results. eso-discovers-earth-size-planet-in- VI. The Shadow and Mass of the Central habitable-zone-of-nearest-star,. Black Hole. , 875(1):L6, Apr 2019. doi: 10.3847/2041-8213/ab1141. [6] V. S. Meadows, C. T. Reinhard, et al. Ex- oplanet biosignatures: understanding oxygen [14] Event horizon telescope. https: as a biosignature in the context of its environ- //eventhorizontelescope.org. ment. Astrobiology, 18(6):630–662, 2018. [15] Pallab Ghosh. First ever black hole im- [7] SPACE.com - Alien Life Hunt: Oxy- age released. https://www.bbc.com/news/ gen Isn’t the Only Possible Sign of Life. science-environment-47873592. https://www.space.com/39476-alien- [16] Scientist superstar katie bouman designed life-biosignature-gases-oxygen.html. algorithm for black hole image. https: [8] NASA - HabEx, Habitable Exoplanet Obser- //phys.org/news/2019-04-scientist- vatory. https://www.jpl.nasa.gov/habex/,. superstar-katie-bouman-algorithm.html.

2

11