An ice sheet is a large mass of glacial ice that covers an extensive area of land, typically more than 50,000 square kilometers. These sheets form over thousands of years from accumulated snowfall that compresses into ice. The two main ice sheets on Earth are found in Antarctica and Greenland. Ice sheets play a crucial role in the global climate system and sea level regulation. As they melt due to rising temperatures, they contribute to rising sea levels, which can impact coastal communities and ecosystems. Monitoring ice sheets is essential for understanding climate change and its effects on the planet.