“Star Trek” would have us believe that space is the final frontier, but with apologies to the armies of Trekkies, their oracle might be a tad off base. Though we know little about outer space, we still have plenty of frontiers to explore here on our home planet. And they’re losing the race of discovery.

Hollywood giant James Cameron, director of mega-blockbusters such as “Titanic” and “Avatar,” brought this message to Capitol Hill last week, along with the single-seat submersible that he used to become the third human to journey to the deepest point of the world’s oceans—the Marianas Trench. By contrast, more than 500 people have journeyed into space—including Sen. Bill Nelson (D-FL), who sits on the committee before which Cameron testified—and 12 people have actually set foot on the surface of the moon.

All it takes is a quick comparison of the budgets for NASA and the National Oceanic and Atmospheric Administration, or NOAA, to understand why space exploration is outpacing its ocean counterpart by such a wide margin.

In fiscal year 2013 NASA’s annual exploration budget was roughly $3.8 billion. That same year, total funding for everything NOAA does—fishery management, weather and climate forecasting, ocean research and management, among many other programs—was about $5 billion, and NOAA’s Office of Exploration and Research received just $23.7 million. Something is wrong with this picture.

Space travel is certainly expensive. But as Cameron proved with his dive that cost approximately $8 million, deep-sea exploration is pricey as well. And that’s not the only similarity between space and ocean travel: Both are dark, cold, and completely inhospitable to human life.

Yet space travel excites Americans’ imaginations in a way ocean exploration never has. To put this in terms Cameron may be familiar with, just think of how stories are told on screens both big and small: Space dominates, with “Star Trek,” “Star Wars,” “Battlestar Galactica,” “Buck Rogers in the 25th Century,” and “2001 A Space Odyssey.” Then there are B-movies such as “Plan Nine From Outer Space” and everything ever mocked on “Mystery Science Theater 2000.” There are even parodies: “Spaceballs,” “Galaxy Quest,” and “Mars Attacks!” And let’s not forget Cameron’s own contributions: “Aliens” and “Avatar.”

When it comes to the ocean, we have “20,000 Leagues Under the Sea,” “SpongeBob SquarePants,” and Cameron’s somewhat lesser-known film “The Abyss.” And that’s about it.

This imbalance in pop culture is illustrative of what plays out in real life. We rejoiced along with the NASA mission-control room when the Mars rover landed on the red planet late last year. One particularly exuberant scientist, known as “Mohawk Guy” for his audacious hairdo, became a minor celebrity and even fielded his share of spontaneous marriage proposals. But when Cameron bottomed out in the Challenger Deep more than 36,000 feet below the surface of the sea, it was met with resounding indifference from all but the dorkiest of ocean nerds such as myself.

Part of this incongruity comes from access. No matter where we live, we can go outside on a clear night, look up into the sky, and wonder about what’s out there. We’re presented with a spectacular vista of stars, planets, meteorites, and even the occasional comet or aurora. We have all been wishing on stars since we were children. Only the lucky few can gaze out at the ocean from their doorstep, and even those who do cannot see all that lies beneath the waves.

As a result, the facts about ocean exploration are pretty bleak. Humans have laid eyes on less than 5 percent of the ocean, and we have better maps of the surface of Mars than we do of America’s exclusive economic zone—the undersea territory reaching out 200 miles from our shores.

Sure, space is sexy. But the oceans are too. To those intrigued by the quest for alien life, consider this: Scientists estimate that we still have not discovered 91 percent of the species that live in our oceans. And some of them look pretty outlandish. Go ahead and Google the deepsea hatchetfish, frill shark, or Bathynomus giganteus.

In a time of shrinking budgets and increased scrutiny on the return for our investments, we should be taking a long, hard look at how we are prioritizing our exploration dollars. If the goal of government spending is to spur growth in the private sector, entrepreneurs are far more likely to find inspiration down in the depths of the ocean than up in the heavens. The ocean already provides us with about half the oxygen we breathe, our single largest source of protein, a wealth of mineral resources, key ingredients for pharmaceuticals, and marine biotechnology.

Of course space exportation does have benefits beyond the “cool factor” of putting people on the moon and astronaut-bards playing David Bowie covers in space. Inventions created to facilitate space travel have become ubiquitous in our lives—cell-phone cameras, scratch-resistant lenses, and water-filtration systems, just to name a few—and research conducted in outer space has led to breakthroughs here on earth in the technological and medical fields. Yet despite far-fetched plans to mine asteroids for rare metals, the only tangible goods brought back from space to date remain a few piles of moon rocks.

The deep seabed is a much more likely source of so-called rare-earth metals than distant asteroids. Earlier this year the United Nations published its first plan for management of mineral resources beneath the high seas that are outside the jurisdiction of any individual country. The United States has not been able to participate in negotiations around this policy because we are not among the 185 nations that have ratified the U.N. Convention on the Law of the Sea, which governs such activity.

With or without the United States on board, the potential for economic development in the most remote places on the planet is vast and about to leap to the next level. Earlier this year Japan announced that it has discovered a massive supply of rare earth both within its exclusive economic zone and in international waters. This follows reports in 2011 that China sent at least one exploratory mission to the seabed beneath international waters in the Pacific Ocean. There is a real opportunity for our nation to lead in this area, but we must invest and join the rest of the world in creating the governance structure for these activities.

Toward the end of last week’s hearing, Sen. Mark Begich (D-AK), who chairs the Subcommittee on Oceans, Atmosphere, Fisheries, and Coast Guard, hypothetically asked where we would be today if we had spent half as much money exploring the oceans as we have spent exploring space. Given the current financial climate in Congress, we won’t find the answer to his question on Capitol Hill.

But there may be another way.

Cameron is currently in preproduction on the second and third “Avatar” films. He says the former will be set on an ocean planet. No one except he and his fellow producers at 20th Century Fox really know how much the first installment of the movie series cost, but estimates peg it at approximately $250 million—or 10 times the total funding for NOAA’s Ocean Exploration program. Since the original “Avatar” grossed more than $2 billion at the box office worldwide, if NASA isn’t willing to hand over a bit of its riches to help their oceanic co-explorers, maybe Cameron and his studio partners can chip a percent or two off the gross from “Avatar 2” to help fill the gap.

Come to think of it, if the key to exploring the oceans hinges either on Hollywood giving up profits or Congress increasing spending, maybe we are more likely to mine asteroids after all.

Michael Conathan is the Director of Ocean Policy at the Center for American Progress. Judy Li, an intern at the Center for American Progress, contributed to this work.