08/25/2012 04:53 pm ET

Neil Armstrong Dead: Twitter Reacts To Death Of First Man On The Moon (TWEETS)

FILE - In this March 9, 1966 file photo, Astronaut Neil Armstrong is seated during a suiting up exercise Cape Kennedy, Florid
FILE - In this March 9, 1966 file photo, Astronaut Neil Armstrong is seated during a suiting up exercise Cape Kennedy, Florida, in preparation for the Gemini 8 flight. The family of Neil Armstrong, the first man to walk on the moon, says he has died at age 82. A statement from the family says he died following complications resulting from cardiovascular procedures. It doesn't say where he died. Armstrong commanded the Apollo 11 spacecraft that landed on the moon July 20, 1969. He radioed back to Earth the historic news of "one giant leap for mankind." Armstrong and fellow astronaut Edwin "Buzz" Aldrin spent nearly three hours walking on the moon, collecting samples, conducting experiments and taking photographs. In all, 12 Americans walked on the moon from 1969 to 1972. (AP Photo/FILE)

It's a sad day for those who long to venture into space, and for those who prefer to watch those adventures from the comforts of their own home.

On Saturday afternoon, news that Neil Armstrong, the first man to walk on the moon, had died shocked and saddened many. Within minutes, news of Armstrongs' death became a worldwide trending topic as space lovers, scientists, journalists, and celebrities shared their emotional and heartfelt messages, with the word "hero" used frequently.

His partner on the Apollo 11 mission, Buzz Aldrin, released a statement about the passing of his close friend:

I am very saddened to learn of the passing of Neil Armstrong today. Neil and I trained together as technical partners but were also good friends who will always be connected through our participation in the mission of Apollo 11. Whenever I look at the moon it reminds me of the moment over four decades ago when I realized that even though we were farther away from earth than two humans had ever been, we were not alone. Virtually the entire world took that memorable journey with us. I know I am joined by millions of others in mourning the passing of a true American hero and the best pilot I ever knew. My friend Neil took the small step but giant leap that changed the world and will forever be remembered as a landmark moment in human history. I had truly hoped that in 2019, we would be standing together along with our colleague Mike Collins to commemorate the 50th Anniversary of our moon landing. Regrettably, this is not to be. Neil will most certainly be there with us in spirit.

On behalf of the Aldrin family, we extend our deepest condolences to Carol and the entire Armstrong family. I will miss my friend Neil as I know our fellow citizens and people around world will miss this foremost aviation and space pioneer.
May he Rest in Peace

According to NBC News, Armstrong passed away at 2:45 p.m. at the age of 82, suffering complications following his recent cardiac bypass surgery.

On July 20, 1969, Armstrong and Aldrin made history as the first people to ever walk on the moon. Armstrong will forever be remember for the famous words he spoke as he planted his feet on moon: "One small step for man, one giant leap for mankind."

Launch the gallery below to see reactions on Twitter:

Neil Armstrong