This is an updated version of the Pale Blue Dot image taken by the Voyager 1 spacecraft 30 years ago today. It was created using modern image-processing software and techniques while trying to remain faithful to the original. Like the original, this new color view shows the Earth as a single blue pixel in the vastness of space. Rays of sunlight scattered within the camera optics stretch across the scene, one of which intersects with Earth. Look closely at the stripe just right of center. That speck a bit past half way up isn’t dust on your screen. It’s the Earth.
The image was taken just before Voyager 1’s cameras were turned off to conserve power because the probe would not make another planetary flyby. Shutting down instruments and other systems on the two Voyager spacecraft has been a gradual and ongoing process that has helped keep them running as they have left the Solar System.
Image Credit: NASA
This video takes us around the Moon and shows how it is illuminated not only by the brilliant light of the Sun but also by light reflected from the Earth. The trip starts on the side facing away from Earth where part of the surface is brightly illuminated by the Sun but the rest is totally dark. Moving around the Moon, the Earth rises, and its reflected bluish light illuminates the Moon’s surface. This dull glow is the earthshine. (You can clearly see it from Earth when the Moon appears as a crescent in the evening or morning sky.) When the Sun emerges from behind the Moon, the brilliant crescent is seen, but the earthshine is still faintly visible.
Video Credit: ESO
The Cassini spacecraft snapped this picture of the Earth as seen from near Saturn in 2013.
Image Credit: NASA
… here in the Northern Hemisphere. The equinox occurred last week. At an equinox Earth’s terminator, the dividing line between day and night, runs through the planet’s north and south poles as seen at the start of this time-lapse video which crams an entire year into twelve seconds. It was put together using Meteosat infrared images taken every day at the same local time from a geosynchronous orbit. The video actually starts at the September 2010 equinox. As the Earth revolves around the Sun, the terminator tilts as less daily sunlight falls on the northern hemisphere, reaching the solstice and northern hemisphere winter at the maximum tilt. As the year continues, the terminator tilts back again to the March 2011 equinox halfway through the video. Then the terminator swings past the poles, until the June 2011 solstice, the start of northern summer. The video ends as the September equinox returns.
Video Credit: NASA / Meteosat / Robert Simmon
Because the amount of energy necessary for an interplanetary flight is available from practical launch vehicles, spacecraft often use a planet’s gravity to provide some of the energy needed for final trajectories. Properly executed, one or more gravity assist flybys can be enough to change a spacecraft’s speed and direction so it can enter orbit around another world or fly off into the Kuiper Belt or even interstellar space.
This view of Earth was captured in 2007 on the second of three Earth flybys made by ESA’s comet-chasing Rosetta spacecraft on its ten year journey to Comet 67P/Churyumov-Gerasimenko.
Image Credit: ESA