Quaternary

Geologic period that occurred roughly 1.6 million years ago to today. During much of this period continental glaciers in the Northern Hemisphere covered large regions of land surcae in the high and mid-latitudes. Homo sapiens appear about 200,000 years BP (before present) and become the first species to alter the Earth's environment on a large-scale.Radarsat Satellite program established by the Canadian Space Agency for the purpose of remotely sensing the Earth's resources. Radarsat uses an active sensing system that transmits microwaves. See the following website for more information - Radarsat.