Vaccuum Proof Brooms: Don Freeman, Space Witch (New York: Viking Press, 1959).
From the Osbourne Collection in Toronto, where I touched down for the afternoon.
Tilly the witch decides she wants to scare aliens for Halloween so she brews up a spell to make a sort of plastic to make a space broom, stitches a space suit from inner tube tires and crams her cat into the broom.
The broom hurtles into space, past the moon, which hasn't a single creature to scare. They miss Mars and hurtle around saturn and into the Milky Way: " But not a single drop of milk did they see in all that field of twinkling stars/And even a cat could tell they were lost."
Eventually they crash and see small Martians. They follow them into their doorway, only for the Martians to jump out on them with a "Boo". They have landed on Earth and the children are trick or treating. As Kit curls up in his basket he purrs, "There's no space like home."