On June 22, 2000, NASA announced possible evidence of present-day liquid water on Mars. Scientists analyzed data from NASA's Mars Global Surveyor spacecraft and found what appeared to be gullies formed by flowing water. They also found debris and mud deposits these flows may have left behind. Spacecraft on and around the planet had already seen evidence that vast oceans of water existed on Mars a long time ago, but researchers have yet to confirm that liquid water still exists on the planet today. They have, however, found water ice at Mars's north and south poles. Gullies and other dark streaks on the Martian surface known as recurring slope lineae look like they might contain super-salty water brine, but so far no real data has confirmed the presence of liquid water anywhere on the Martian surface.