Downloads the baseline ephemeris, time, and nutation data files.
Fetches the DE440s planetary SPK kernel, the IERS Earth orientation file
finals2000A.all, the NAIF leap-second kernel naif0012.tls, and the IAU
2000A nutation tables (~32 MB total) into ephemeris/ under
EphCore.Ephemeris.Kernels.base_dir/0 — priv/ unless :kernel_base_dir is
configured. Existing files are kept unless --force is given.
Usage: mix eph.download_kernels mix eph.download_kernels --force
For asteroid kernels, see mix eph.generate_kernel. For the optional
Hipparcos fixed-star catalog, run mix eph.setup_stars.