Today’s factismal: The first Landsat was launched 42 years ago; we are now up to Landsat 8.
If you ask any geologist or oceanographer what the most successful satellite program ever is, odds are that they’ll tell you it is Landsat. The program started in 1966, when scientists realized that using different colors of light (a trick known as multispectral scanning) could help them see the world in a new way. But the colors that they used weren’t red, green, and blue; instead, they used colors like infrared and ultraviolet. Though the human eye can’t see those colors, many plants can. They either absorb the energy for use in creating sugars or reflect it to attract insects and other pollinators. So by using these unusual colors of light, the scientists were able to map out where plants were growing and what the soil and rocks look like better than just using visible light would allow.
But it took time to develop sensors that were good enough and small enough to fit into a satellite – six years of time, to be exact. The first Landsat was launched in 1972, and proved to be an immediate success. Though it only recorded 1,692 images, they were something special. In those images, Landsat discovered new islands and showed forests being logged and the remains of ancient cities.
Since that original launch, seven more Landsats have been launched (though only six made it to orbit). And the current edition, Landsat 8, was put into orbit just over a year ago and is giving us amazing new images of the Earth. If you’d like to help put those new images to good use, then why not join the Geo-Wiki Project? They want to improve land cover maps using resources such as Landsat. To join, head on over to: