This helps you know each player's current score at all times. This can work both ways, of course - some groups will like it because they don't have to take time to try to figure out someone else's score, but some groups might prefer not to know because they don't monitor other players' scores anyway. Personally, I like to know all trackable information because it adds depth without requiring a lot of memorization.
You'll need about 20 small markers in each player color. I'm using cubes from Macao and Walnut Grove. For each card of Mars, Saturn, Jupiter, and Mercury you have, you will place one cube on the relevant row of the scoring track. At the beginning of the game, just set the cubes in the margins until you've actually earned vp's in that row. For each asset you develop in a row, advance all your cubes in that row one space to the right, skipping the x's since odd numbers are impossible for Mercury and Mars. Multiply the column value by the number of cubes you have in the row to get your score in that row.
For example, at the start of the game, each player will put one cube on the 4 vp space in Mars, and for each Mars card they buy, they will add a cube to that one (in the space currently occupied by the original one). Since no other cubes are on the scoring track yet, everyone's score is 4 (plus whatever Vesta would give them, but that's pointless to track). For each colonist they add, they will move each Mars cube one space right.
Minerva is easy. You only need one cube for each card, and you just move it along as you build houses in cities of that type. The score is depicted in each cell.
# of cubes = # of cards - 1 (no cube for Vesta)
add cubes as you add cards to your hand
move cubes to the right as you score in that row
multiply column value times cubes in that row (exc. Minerva)
Minerva scores are given in cells
add all row values to estimate score