By David M. Shribman Earlier this month, on the 80th anniversary of D-Day, the country came to realize that only a few centenarians remain from the nearly 160,000 involved in the opening days of the invasion of occupied France. One of them, Robert Persichitti, 102, died en route to the commemoration.

He had also served at Guam, Iwo Jima and Okinawa. Then, just a few days ago, William Anders, the Apollo 8 astronaut remembered for snapping the “Earthrise” photograph in 1968, died. At age 90, he was flying alone when his plane crashed off the San Juan Islands in Washington state.

He never stepped on the moon, but, perhaps more than any of his astronaut colleagues, he expanded our vision of the Earth. Only a third of those who left their footprints on the moon still walk the Earth. Apollo 11, which took the first humans to the surface of the Earth’s lone satellite, is well remembered for what Neil Armstrong described as “one giant leap for mankind.

” But the passing of Anders is a reminder of the revelation that came with that photograph, a change in human perspective that can be described as earth-shattering. Anders knew that. “We came all this way to explore the moon,” he said, “and the most important thing is that we discovered the Earth.

” The glimpse of the astronauts’ home planet — an icy-blue celestial body, pockmarked with bright white clouds, hanging in the heavens, suspended against the black of deep space — astonished the men in their tiny capsule.