Friends and colleagues gathered Wednesday at the Lincoln Center to pay tribute to legendary newsman Walter Cronkite who died in July.

President Barack Obama in his address at the New York based Lincoln Center described Walter Cronkite a voice of certainty in a world that was growing more and more uncertain.

Speaking at a memorial service for the legendary newsman, Obama acknowledged he hadn't known Cronkite personally, but I have benefited as a citizen from his dogged pursuit of the truth.

We are grateful to him for altering and illuminating our time, Obama added.

Cronkite died on July 17 at the age of 92, following nearly 20 years of presenting the nightly news during a historic period in history when the nation brought a man to the moon and saw television broadcasts in color for the first time.

He is best remembered for his coverage of the Apollo 11 and succeeding moon landings, as well as John F. Kennedy's death.

Barack obama