The only fix to your script is to use `display` command to open image (NOT `open` command).[0]

    wget $(curl -s https://www.star.nesdis.noaa.gov/GOES/fulldisk.php?sat=G16 | grep -o -e 'https://cdn.star.nesdis.noaa.gov/GOES16/ABI/FD/GEOCOLOR/[0-9]*_GOES16-ABI-FD-GEOCOLOR-1808x1808.jpg' | head -1) -O earth.jpg && display earth.jpg

And here is my resulted preview.[1]

UPD: Found that this CDN[2] also has static links to latest image, so script could be much more simplified by dropping `curl` and `grep`:

    wget -c https://cdn.star.nesdis.noaa.gov/GOES16/ABI/FD/GEOCOLOR/1808x1808.jpg -O earth.jpg && display earth.jpg

[0] https://www.computerhope.com/issues/ch001720.htm

[1] https://i.imgur.com/gFaVvhz.jpg

[2] https://cdn.star.nesdis.noaa.gov/GOES16/ABI/FD/GEOCOLOR/