NASA’s Deep Impact Films Earth as an Alien World
“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, Md. Deming is deputy principal investigator for EPOXI, and leads the EPOCh observations. “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. 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.” That happens because plants reflect more strongly in the near-infrared, Deming explained. Hence the video illustrates the potential for detecting vegetated land masses on extrasolar planets by looking for variations in the intensity of their near-infrared light as the planet rotates.