Structuring planet data
Hi there @owolagbadavid — welcome to the community, and thanks for sending in your code!
this looks pretty much perfect — the only thing I have to call out here is that wherever you have used scope values of col/colgroup, you should instead be using row/rowgroup — those headers are being used as a header for a group of rows, not a group of columns.
And the one for “Dwarf planets” should really be row, not rowgroup — it is only the heading for a single row.