Facebook has mapped populations in 23 countries as it explores satellites

• Facebook used satellite-based data and government census information to map the Earth's entire human population.
• The data set has a resolution of five meters and knows where man-made structures are everywhere on the planet.
• Facebook has been hiring aerospace engineers and has a new executive hired to forge partnerships with aerospace and satellite companies.

Facebook doesn't only know what its 2 billion users "Like."

It now knows where millions of humans live, everywhere on Earth, to within 15 feet.

The company has created a data map of the human population by combining government census numbers with information it's obtained from space satellites, according to Janna Lewis, Facebook's head of strategic innovation partnerships and sourcing. A Facebook representative later told CNBC that this map currently covers 23 countries, up from 20 countries mentioned in this blog post from February 2016.

The mapping technology, which Facebook says it developed itself, can pinpoint any man-made structures in any country on Earth to a resolution of five meters.

Facebook is using the data to understand the precise distribution of humans around the planet.

That will help the company determine what types of internet service — based either on land, in the air or in space — it can use to reach consumers who now have no (or very low quality) internet connections.

"Satellites are exciting for us. Our data showed the best way to connect cities is an internet in the sky," Lewis told about 150 people gathered in San Francisco this week for a Space Technology and Investment Forum sponsored by the Space Foundation.

"We're trying to connect people from the stratosphere and from space," using high-altitude drone aircraft and satellites, to supplement Earth-based networks, said Lewis.

Facebook hired Lewis, a former intellectual property lawyer with extensive experience in international aerospace law, about one year ago.

Her job, as she told the forum, is to work with partners in the aerospace industry to build a multi-pronged network to serve the entire planet.

The data is used "to know the population distribution" of Earth to figure out "the best connectivity technologies" in different locales, Lewis said. "We see these as a viable option for serving these populations" that are "unconnected or under-connected," she said.

In addition to Lewis, Facebook is also hiring aerospace engineers to help it crack this market.

The mapping technology is part of a much broader effort by U.S. companies to take advantage of a slew of data now available from the hundreds of satellites orbiting the earth.

"All this satellite data is coming from space, so people are trying to figure out what the business opportunities are," says Edward Swallow, senior vice president for civil and commercial systems for the Aerospace Corporation, an entity set up by the government in 1960 to protect America's pre-eminence in space.

Facebook rival Google, for example, sold its satellite-imaging business, formerly called Skybox, earlier this year "because they figured out they could get the data without having its own satellites," Swallow told CNBC in an interview.

Cheaper launches, more data

Space-related investment and market development are being driven by two things: the plummeting cost of launching satellites and the wealth of data they produce.

New aerospace companies, including Elon Musk's SpaceX, Jeff Bezos' Blue Origin and Richard Branson's Virgin Galactic and Virgin Orbit, have driven down the cost of launching a satellite into low Earth orbit dramatically.

Thanks to companies founded by this "billionaire boys club" — as some at the space investing confab referred to them — a company can now get a payload into space for as low as "tens of thousands of dollars per kilogram," said Monica Jan, senior director of strategy and customer experience for Virgin Orbit.

Before these companies entered the market, satellite launches typically cost millions or even billions of dollars, said Jan, who has worked in the aerospace industry for decades.

Virgin Orbit, based in Long Beach, California, was spun out of Virgin Galactic earlier this year to focus on small-satellite launches.

When asked by CNBC what she took away from Lewis' earlier presentation, she said "it sounds like they [Facebook] want to create a multi-tier system," or one that uses networks based on Earth, in the stratosphere and in space.

A space-based internet

All of this activity has been spurred by the increasing commercialization of space, which was formerly an expensive realm inhabited by nations alone.

Of the 576 U.S. satellites now in orbit, 286 — or roughly half — were launched for commercial reasons, according to Steve Butow, the West Coast military lead for the Defense Innovation Unit Experimental, or DIUX.

The DIUX was set up during the Obama administration to speed the deployment of new technologies into the U.S. armed forces.

The end result of all this investment will likely be a "space-based broadband data network" that will be the basis of "a new space economy," Butow told the space investing confab in San Francisco.

If and when that becomes a reality, Facebook will be ready for it.