NASA Worldview is a free online visualization tool that is a great launchpad for learners who are new (or veteran) users of satellite data.
Educational Resources - Search Tool
An urban heat island is a phenomenon that is best described when a city experiences much warmer temperatures than in nearby rural areas. The sun’s heat and light reach the city and the country in the same way. The difference in temperature between urban and less-developed rural areas has to do with how well the surfaces in each environment absorb and hold heat.