https://releases.ubuntu.com/20.04/
https://docs.anaconda.com/anaconda/install/linux/
https://cxc.cfa.harvard.edu/ciao/download/
https://cxc.cfa.harvard.edu/ciao/download/caldb.html
https://github.com/jeremysanders/contbin
https://heasarc.gsfc.nasa.gov/lheasoft/download.html