How would you know from a distance of 10 million or more miles that Earth had oceans? “A ‘sun glint’ can be seen in the movie, caused by light reflected from Earth’s oceans, and similar glints from extra-solar planets could indicate alien oceans,” Deming said in a NASA press release. Deming is leading the search for extra-solar (outside our solar system) planets during Deep Impact’s extended mission: a cruise to the Hartley 2 comet and a fly-by of it in November 2010.Īmong the leading criteria for habitable planets is the presence of liquid water. “Our video shows some specific features that are important for observations of Earth-like planets orbiting other stars,” said Drake Deming of NASA’s Goddard Space Flight Center in Greenbelt, Maryland. Other spacecraft have imaged Earth and the Moon from space, but Deep Impact is the first to show a transit of Earth with enough detail to see large craters on the moon and oceans and continents on Earth.Ī far cry from the very detailed images of our planet that satellites closer to Earth provide, the video suggests what attributes of a life-supporting planet we could recognize from tens of millions of miles away. In the final image, the Atlantic Ocean has rotated into view. The first image shows eastern Africa and the Arabian Peninsula.
A few of the images in the sequence are shown above. The video capture the transit of the Moon across an Earth backdrop that starts with the western Pacific in view. Shot at 15 minute intervals on May 28 and 29, 2008, the images have been stitched together into a movie that encompasses one full rotation of Earth.
Infrared web quality (570 kB QuickTime)įrom 31 million miles away, how could you tell that there was life on Earth? Recently, scientists used the remote vantage point of NASA’s Deep Impact spacecraft to shoot a sequence of images that will help to help answer that question-and will guide them in the search for planets outside our solar system that could also harbor life.