Here's a riddle for you. What is the size and weight of a full-grown Indian elephant, flies faster than a speeding bullet, and has been enormously helpful to the world's most distinguished space administration? Why, the Terra satellite of course! The wildly successful Terra satellite has gathered a staggering amount of data about Earth's land, atmosphere, and water. This data allows scientists to make great strides in understanding Earth's systems and the way they interact. In the early '90s, NASA scientists had limited means of tracking global trends in quantities such as temperature, pollution, and weather patterns. Then came the revolutionary creation of Terra, which provided a means to acquire and map more types of data, simultaneously and in more detail than ever before. The satellite was launched on December 18th, 1999 from Vandenberg Air Force Base in California, and began collecting data about two months later. Terra was only expected to operate in orbit for about six years, but 15 years later, Terra has surpassed expectations. Terra gathers information through five instruments, each serving a unique purpose. With these instruments working together, we have been able to see Earth as a system. Terra's instruments allow us to look at the oceans, atmosphere, land, ice, and life all at once and to see the relationships between them. The more data that Terra collects, the more valuable it becomes. It's been so great that Terra had lasted more than the projected six years, because this allows us to see longer-term and more subtle trends. For example, in this 15-year time-span, we have been able to observe several El Nino cycles, which typically take 5-7 years each, and to capture the full course of an 11-year solar cycle and see how it affects processes on Earth. We've also been able to see events like the large Icelandic volcano eruption in 2010, which Terra wouldn't have been able to see if it had lasted only six years. Terra has paved the way for subsequent Earth-observing missions, such as Aqua and Aura, and has started a lasting legacy of understanding the planet on which we live. Assuming nothing breaks, Terra is estimated to end its incredible journey around the year 2021. We hope you'll join us in toasting the satellite's 15 prosperous years. Here's to the great strides NASA has made and to our rewarding future.