It took millions of years for the Aral Sea to form, and just a few decades to divest it of water.

Formerly a gigantic lake straddling Kazakhstan and Uzbekistan, the ocean-sized body of water is well on its way to disappearing. In fact one section has completely dried up since 2000, the space agency’s Earth Observatory said on September 26.

Once the fourth largest lake in the world, Aral was replenished by rivers funneling snow melt, and they supported a thriving economy based on fisheries, reported the Washington Post. But once the two rivers that fed it, the Amu Darya and the Syr Darya, were dammed up, no water could get in. Further, the lake was drained by irrigation projects, its water destined for crops being grown in the deserts of Kazhakstan, Turkmenistan, and Uzbekistan, Time magazine reported. Millions of gallons were siphoned off for cotton fields and rice paddies, according to NASA.

“Beginning in the 1960s, farmers and state offices in Uzbekistan, Kazakhstan and Central Asian states opened significant diversions from the rivers that supply water to the lake, thus siphoning off millions of gallons to irrigate cotton fields and rice paddies,” said NASA. “As recently as 1965, the Aral Sea received about 50 cubic kilometers of fresh water per year—a number that fell to zero by the early 1980s. Consequently, concentrations of salts and minerals began to rise in the shrinking body of water. That change in chemistry has led to staggering alterations in the lake’s ecology, causing precipitous drops in the Aral Sea’s fish population.”

Although at one point part of the lake appeared to rebound, overall it has shrunk markedly, and steadily, since the 1960s. When NASA’s satellite photos picked up the shrinking process in 2000, the water line was already much removed from its former position, and “the lake was already a fraction of its 1960 extent,” NASA said.

By 2000, the Northern Aral Sea was completely separate from the Southern Aral Sea, NASA said, and the southern portion in turn had become two lobes, eastern and western, “that remained tenuously connected at both ends.”

In 2009, desperate to save at least some of the lake, the authorities in Kazakhstan decided to amputate, adding a dam between the northern and southern parts. Water levels in the southern portion’s eastern lobe bounced around between 2009 and 2014, depending on how wet or dry the year was, NASA said. But this year the dry won out. By the time these photos were taken on August 19, 2014, the eastern lobe of this once 26,000-square-mile lake was no more.

“This is the first time the eastern basin has completely dried in modern times,” said Philip Micklin, a geographer emeritus from Western Michigan University and an Aral Sea expert, in a NASA statement. “And it is likely the first time it has completely dried in 600 years, since Medieval desiccation associated with diversion of Amu Darya to the Caspian Sea.”

It might behoove those who disagree that human activity could be irrevocably changing our environment, and not to our benefit, to check out NASA’s web page on the Shrinking Aral Sea. And for details on the environmental effects being monitored and measured, try Columbia University’s website The Aral Sea Crisis.