Apollo 11 astronaut Buzz Aldrin wanted to send a message “to the cosmos” and probably to NASA as well. On Monday, the 85-year-old posted a picture on Twitter standing in front of Stonehenge revealing his T-shirt, Clark Kent style, that reads, “Get your a** on Mars.”

From an overly analytical perspective, the actual juxtaposition of an ancient monument, the second man to walk on the Moon and the proposition of a manned settlement on Mars all in the same photo is all quite profound. Stonehenge, believed to have some astronomical significance, sits as the predecessor to Apollo 11’s historic landing and is the predecessor to any future explorations beyond our Earth. That is, if there are any further manned explorations beyond Earth.

Apollo 11 astronaut Buzz Aldrin is calling for more research  on Mars. PHOTO VIA FLICKR USER Campus Party Brazil

Apollo 11 astronaut Buzz Aldrin is calling for more research on Mars. PHOTO VIA FLICKR USER Campus Party Brazil

The past 40 years have seen wildly astounding astronomical discoveries, but Aldrin is convinced that continuing human space travel, and eventually colonization, is essential to science and our society. In an editorial for Time magazine in 2007, Aldrin wrote, “When Neil Armstrong and I stepped upon the surface of the moon … we fulfilled a dream held by humankind for centuries. Yes, it was one small step. Today, more steps are needed.”

Aldrin has been a steady and persistent advocate of the United States actually developing a settlement on the surface of the Red Planet for research opportunities, as well as commercial resources. With a Ph.D. in astronautics and experience as a government advisor, his aspirations for space travel are exciting due to the fact that they may someday be possible.

In the Time article, he expressed his wish to “establish a rotating permanence” on Mars with other nations, but implied a desire for the United States to take on the challenge, prompting the world to follow.

NASA has revealed that it has its sights set on Mars, but there are no real plans in the works to get there. How could there be? The United States faces much more pressing issues, and funding has been cut dramatically from the space program. Buzz Aldrin is one of the many voices emphasizing the importance of manned space travel and exploration, and as a nation, some decisions have to be made.

Another article by the former astronaut from July 2014, just before the 45th anniversary of the Apollo 11 landing, highlights Aldrin’s hopes for the United States in the forum of the exploration of the universe, in the form of deep questions.

He gives an important call to action to the United States — should we leave space travel up to another powerful nation to dominate, like Russia or China? “To me, the answer is obvious,” he remarked.

Shouldn’t the United States forge “a path toward Mars,” by starting the process of Martian settlement and helping other nations join the push, too? Is another expensive Apollo-esque mission feasible for the United States right now?

The last question is a major stumbling block in the process of getting humans on Mars. Not only does it cost “hundreds of billions of dollars” to launch a program similar to the Apollo missions, but Aldrin expresses the need for preliminary research on a nearby asteroid, which would cost a small fortune by itself. New technology would most certainly be needed, adding to the tab.

Nevertheless, Buzz Aldrin continues to advocate for the eventual manned settlement on Mars. Although his tweet on Monday was comical and viral, his push for U.S. Martian exploration has been a long process.