Buzz Aldrin, one of the first two men to walk on the moon back in 1969, has used one of mankind's oldest monuments as a backdrop for his call for a new leap in space exploration.
The veteran astronaut posted a picture to his Twitter feed Monday of himself in front of England's famed Stonehenge, a prehistoric stone circle, wearing a T-shirt proclaiming "Get your ass to Mars."
It's part of his campaign for the United States to focus on a longer term goal of human settlement on Mars.
Aldrin wrote in an opinion piece for CNN last year, "The moment to begin could be on the occasion of the 50th anniversary of Apollo 11's touchdown on the moon.
"We can make a courageous, Kennedyesque commitment to America's future in deep space. The U.S. President could utter these momentous words: 'I believe this nation should commit itself, within two decades, to commencing an America-led, permanent presence on the planet Mars.'"
Aldrin, best known for his Apollo 11 moonwalk with Neil Armstrong in July 1969, holds a doctoral degree in astronautics and has also consulted for the U.S. government and addressed Congress on the future of the country's space program.
The former NASA astronaut's focus is also on how to make space more accessible to everyday people.