The green parts of the blue planet. Image courtesy of NASA/NOAA Most views of our planet from space draw attention to the water-covered majority of its surface, hence the nickname Big Blue Marble. In this visualization of the globe, though, the SUOMI satellite focused on the world's plant life, and shows just how much it can change over the course of a year. The satellite gathered the data between April 2012 to April 2013 by measuring reflections of the sun's energy in the form of visible and near-infrared light. Plants absorb visible light for photosynthesis. In densely vegetated areas like rainforests, then, the leaves absorb the vast majority of visible light and reflect most of the near-infrared light back into space. In contrast, areas without much greenery, such as deserts, reflect the majority of both visible and near-infrared light. The SUOMI satellite determines the density of plants by measuring the ratio of visible and near-infrared light absorbed and reflected. Using this data, researchers mapped the distribution and density of the world's greenery. The animated version shows how much the plant cover changes week to week.
More vegetated areas absorb more visible light and reflect more near-infrared light back into space. Satellites can detect these relative differences, which are used to create vegetation indices. Image courtesy of NASA/NOAA. The maps aren't just made for visual appeal, though. This data has real-world applications, since vegetation plays a major role in the way water and energy cycle through our planet's systems. Seeing the weekly changes in vegetation density may provide early warning for disasters such as droughts, wildfires and even malaria outbreaks. And by integrating vegetation dynamics into weather forecasting models, meteorologists may be better able to predict runoff, surface temperature and relative humidity. Are these maps really detailed enough to make localized predictions, you might ask? Absolutely. In fact, if you were to print the global map out at full resolution, it would require a sheet of paper 93 feet long and 46.5 feet wide.
Image courtesy of NASA/NOAA.