- Moderate-Resolution Imaging Spectroradiometer
- MODIS Web (modis.gsfc.nasa.gov)
MODIS (or Moderate Resolution Imaging Spectroradiometer) is a key instrument aboard the Terra (originally known as EOS AM-1) and Aqua (originally known as EOS PM-1) satellites. Terra’s orbit around the Earth is timed so that it passes from north to south across the equator in the morning, while Aqua passes south to north over the equator in the afternoon. Terra MODIS and Aqua MODIS are viewing the entire Earth’s surface every 1 to 2 days, acquiring data in 36 spectral bands, or groups of wavelengths (see MODIS Technical Specifications). These data will improve our understanding of global dynamics and processes occurring on the land, in the oceans, and in the lower atmosphere. MODIS is playing a vital role in the development of validated, global, interactive Earth system models able to predict global change accurately enough to assist policy makers in making sound decisions concerning the protection of our environment.
- Stingray Nebula (Wikipedia)
The Stingray Nebula (Hen 3-1357) is the youngest-known planetary nebula, having appeared in the 1980s. The nebula is located in the direction of the southern constellation Ara (the Altar), and is located 18,000 light-years (5,600 parsecs) away. Although it is some 130 times the size of the Solar System, the Stingray Nebula is only about one tenth the size of most other known planetary nebulae. The central star of the nebula is the fast-evolving star SAO 244567. Until the early 1970s, it was observed on Earth as a preplanetary nebula in which the gas had not yet become hot and ionized.
- Moderate Resolution Imaging Spectroradiometer (Wikipedia)
The Moderate Resolution Imaging Spectroradiometer (MODIS) is a satellite-based sensor used for earth and climate measurements. There are two MODIS sensors in Earth orbit: one on board the Terra (EOS AM) satellite, launched by NASA in 1999; and one on board the Aqua (EOS PM) satellite, launched in 2002. Since 2011, MODIS operations have been supplemented by VIIRS sensors, such as the one aboard Suomi NPP. The systems often conduct similar operations due to their similar designs and orbits (with VIIRS data systems deisgned to be compatible with MODIS), though they have subtle differences contributing to similar but not identical uses.
