Answer: November 28
Notes: Red Planet Day is observed every year on November 28 to mark a milestone in Mars exploration. On November 28, 1964, NASA launched Mariner 4, the first spacecraft to perform a successful close flyby of Mars. Mariner 4 transmitted the first close-up images of Mars, revealing its barren, cratered surface. The day celebrates scientific progress and inspires continued exploration through rovers, landers, orbiters, and future sample-return missions. Mars is called the Red Planet due to iron oxide (rust) coating its soil and dust, giving it a reddish hue.
