GRE99052002 - 19 MAY 1999 - GREENBELT, MARYLAND, USA: Astronomers using NASA's Hubble Space Telescope have discovered an enormous cyclonic storm system raging in the northern polar regions of the planet Mars, May 19. Nearly four times the size of the state of Texas, the storm is composed of water ice clouds like storm systems on Earth, rather than dust typically found in Martian storms. This image, of color composite data, shows the the storm is more than 1000 km across, featured at the center left. iw/Jim Bell (Cornell U.), Steve Lee (U. Colorado), Mike Wolff (SSI), and NASA UPI