Movie shows alien's-eye view of Earth and Moon

Movie shows alien's-eye view of Earth and Moon
Thu Jul 17, 2008 11:42pm BST

WASHINGTON (Reuters) - A spacecraft sent on a mission to inspect comets has filmed the Earth and its moon from 31 million miles away, making an alien's-eye view of our world.

The two brief sequences show the Moon passing in front of the Earth as it orbits.

"Making a video of Earth from so far away helps the search for other life-bearing planets in the Universe by giving insights into how a distant, Earth-like alien world would appear to us," said University of Maryland astronomer Michael A'Hearn, who leads the project using NASA's Deep Impact spacecraft.

"Our video shows some specific features that are important for observations of Earth-like planets orbiting other stars," added Drake Deming of NASA's Goddard Space Flight Center in Greenbelt, Maryland.

"A 'sun glint' can be seen in the movie, caused by light reflected from Earth's oceans, and similar glints to be observed from extrasolar planets could indicate alien oceans," Deming added.

"Also, we used infrared light instead of the normal red light to make the color composite images, and that makes the land masses much more visible."

The video and other images are available here (link is dead)

"To image Earth in a similar fashion, an alien civilization would need technology far beyond what Earthlings can even dream of building," added Sara Seager, a planetary theorist at the Massachusetts Institute of Technology in Cambridge.

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Video Shows Moon From Other Side
Published: July 19, 2008

A NASA spacecraft designed to look for comets turned its cameras homeward, capturing a unique view of the moon passing in front of the Earth as seen from 31 million miles away. The spacecraft, Deep Impact, took shots at 15-minute intervals, which were combined to make the sequence shown below.

The latest images show the moon and Earth in greater detail than previous ones taken by orbiting spacecraft, showing oceans and continents on our planet and craters on the moon. By studying how Earth looks from so far away, the scientists hope to sharpen their search for alien worlds that may share similar characteristics.

Sara Seager, a planetary theorist at the Massachusetts Institute of Technology and a co-investigator on the extended mission for Deep Impact, notes that the data being gathered are just for planning purposes because the discovery of a good candidate alien planet is a long way off in the future.

But should that time come, by comparing this detailed image of Earth to a glimmering, flickering point source of light, “we want to be able to infer whether there are oceans and continents on another planet,” she said.

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