GRE99052003 - 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 is an enhanced orthographic view of the storm centered on 65 deg. N latitude, 85 deg. W longitude and has been processed to bring out additional detail in the storm's spiral cloud structures. iw/Jim Bell (Cornell U.), Steve Lee (U. Colorado), Mike Wolff (SSI), and NASA UPI