Single Room, Earth View
America's first woman in space describes the beauty of Earth from orbit.
- By Sally Ride
- Air & Space magazine, July 2012
(Page 3 of 5)
Of course, informal observations by individual astronauts are one thing, but more precise measurements are continually being made from space: space shuttle cameras have documented damage to citrus trees in Florida and in rain forests along the Amazon. More sophisticated sensors have measured atmospheric carbon monoxide levels, allowing scientists to study the environmental effects of city emissions and land-clearing fires.
Most of the Earth’s surface is covered with water, and at first glance it all looks the same: blue. But with the right lighting conditions and a couple of orbits of practice, it’s possible to make out the intricate patterns in the oceans—eddies and spirals become visible because of the subtle differences in water color or reflectivity.
Observations and photographs by astronauts have contributed to the understanding of ocean dynamics. For example, the energy balance in the oceans is better understood as a result of discoveries of circular and spiral eddies tens of miles in diameter, of standing waves hundreds of miles long, and of spiral eddies that sometimes trail into one another for thousands of miles. If a scientist wants to study features on this scale, it’s much easier to do from orbit than from a boat.
Believe it or not, an astronaut can also see the wakes of large ships and the contrails of airplanes. The sun angle has to be just right, but when the lighting conditions are perfect, you can follow otherwise invisible oil tankers on the Persian Gulf and trace major shipping lanes through the Mediterranean Sea. Similarly, when atmospheric conditions allow contrail formation, the thousand-mile-long condensation trails let astronauts trace the major air routes across the northern Pacific Ocean.
Part of every orbit takes us to the dark side of the planet. In space, night is very, very black—but that doesn't mean there’s nothing to look at. The lights of cities sparkle; on nights when there was no moon, it was difficult for me to tell the Earth from the sky—the twinkling lights could be stars or they could be small cities. On one nighttime pass from Cuba to Nova Scotia, the entire East Coast of the United States appeared in twinkling outline.