The dust storm that wiped out Martian surface features in amateur telescopes last July could hardly be more dramatic than in the pair of natural-color Hubble Space Telescope images released last week. When the first picture was taken, yellow-brown dust clouds were already beginning to shroud the Hellas basin (medium-bright area at 4 o'clock position on the limb) and the North Polar Cap (top). They soon spread and multiplied to envelop the globe. Both images show nearly the same Martian hemisphere, with dark Sinus Sabaeus and Sinus Meridiani near center.