deb http://archive.ubuntu.com/ubuntu/ bionic-backports main universe multiverse restricted
deb http://archive.ubuntu.com/ubuntu/ bionic main universe multiverse restricted
deb http://archive.ubuntu.com/ubuntu/ bionic-updates main universe multiverse restricted
deb http://security.ubuntu.com/ubuntu/ bionic-security main universe multiverse restricted

Source: upgrade – ESM 401 Unauthorized error on Ubuntu 16.04 – Ask Ubuntu

https://www.americanscientist.org/article/the-orbit-of-the-moon#:~:text=The%20Moon%27s%20orbit%20has%20an,looks%20almost%20like%20a%20circle.&text=The%20Moon%27s%20elliptical%20orbit%20orientation,a%20period%20of%208.85%20years.