On December 7, 1972, NASA astronauts took a parting shot as they left “parking orbit” around Earth and continued on their mission to the Moon. The Apollo 17 crew snapped a photograph of our planet that became one of the most iconic and familiar in all of human history, an image nicknamed the “Blue Marble.”Apollo 17 was the last manned mission to the Moon—no one has ever again been far enough away from Earth to take a similar image. Satellite imagery, however, has documented our planet in even greater detail, from the change in seasons, cloud cover, and even the display of man-made “lights at night.”The unique “Blue Marble” image was possible due to the orientation of the astronauts as they left “parking orbit.” The sun was at their backs, allowing an entire hemisphere to be illuminated. The December solstice was quickly approaching, which put the Northern Hemisphere mostly out-of-frame and made large sections of Antarctica visible.
Term Part of Speech Definition Encyclopedic Entry astronaut Noun
person who takes part in space flights.
visible mass of tiny water droplets or ice crystals in Earth's atmosphere.
Encyclopedic Entry: cloud cloud cover Noun
amount of sky covered with clouds.
to show or reveal.
to keep track of.
half of a sphere, or ball-shaped object.
Encyclopedic Entry: hemisphere iconic Adjective
event or symbol representing a belief, nation, or community.
to shine light on.
body of land surrounded by water.
Encyclopedic Entry: island man-made Noun
produced by people.
carrying one or more people.
important goal or purpose.
Earth's only natural satellite.
(National Aeronautics and Space Administration) the U.S. space agency, whose mission statement is "To reach for new heights and reveal the unknown so that what we do and learn will benefit all humankind."
Northern Hemisphere Noun
half of the Earth between the North Pole and the Equator.
large body of salt water that covers most of the Earth.
Encyclopedic Entry: ocean orientation Noun
an object or person's position in relation to true north.
parking orbit Noun
temporary orbit reached as a launch vehicle boosts a satellite, where it coasts in parking orbit for a while, then fires again to push the vehicle into the final desired trajectory.
piece of land jutting into a body of water.
Encyclopedic Entry: peninsula planet Noun
large, spherical celestial body that regularly rotates around a star.
Encyclopedic Entry: planet rain forest Noun
area of tall, mostly evergreen trees and a high amount of rainfall.
Encyclopedic Entry: Rain forest Sahara Desert Noun
world's largest desert, in north Africa.
satellite imagery Noun
photographs of a planet taken by or from a satellite.
period of the year distinguished by special climatic conditions.
Encyclopedic Entry: season similar Adjective
alike or resembling.
astronomical event that occurs twice a year, when the sun appears directly overhead to observers at the Tropic of Cancer or the Tropic of Capricorn.
Encyclopedic Entry: solstice visible Adjective
able to be seen.