By Jay Kernis
Rock Center

Scientists from around the world are building the world’s most advanced radio telescope in Chile’s Atacama Desert, on a plateau half-way between Earth and space above 40 percent of the planet’s atmosphere.

The observatory, referred to by the acronym ALMA, officially known as the Atacama Large Millimeter/Submillimeter Array, is the highest ever built. Located at 16,500 feet, the antennas will pick up radio and microwave signals from the edge of the universe to see things in space that were once invisible.

Eventually there will be 66 antennas spread across the plateau. All of them can be pointed at the same time at a patch of outer space.

When Rock Center Correspondent Harry Smith found out we could report the ALMA story, he said, “Find me the next Carl Sagan to travel to Chile with us—someone who is passionate about astronomy and can really explain what is going on there.”

We did.

Rock Center

Rock Center's Harry Smith & National Radio Astronomy Observatory Astronomer Scott Ransom

When he was around eight years old, Scott Ransom watched Carl Sagan’s Cosmos series on PBS, read Sagan’s books and decided that he wanted to be an astronaut. He told us, “Once I found out how big the solar system was and how big the galaxy is and how big the universe is—and consequently, how tiny we are, what a tiny little, insignificant component—it just blew my mind.”

He thought he’d go to a military academy, become a test pilot, and then apply for astronaut training. “Because of my eyesight,” Ransom says, “there was no way I would be able to become an astronaut.” But Ransom did graduate from West Point and Harvard, and today spends hours each day exploring outer space.

Dr. Ransom has been an astronomer at the National Radio Astronomy Observatory in Charlottesville, Virginia since 2004. The NRAO leads the North American efforts in Chile, and in Charlottesville, scientists build receivers that capture the radio waves in ALMA’s huge antennas.

"This is the largest, most sophisticated ground-based observatory that the world has ever created," Dr. Ransom said. "It could take weeks or months of observing to do what ALMA's going to be able to do in a day or hour."

A few days after touring ALMA in Chile, Ransom returned to NRAO headquarters in Virginia and talked about his favorite images from space.

CLICK ON EACH IMAGE BELOW to see Harry Smith’s conversation with Dr. Ransom.

In 2010, Ransom received one of his field’s top honors from the American Astronomical Society.  He studies neutron stars and pulsars—the exotic objects that form after the largest stars burn all their hydrogen and explode into a supernova. They may be only 10 or 20 miles across, but, explains Ransom, they can “give off 10-thousand times more energy from its rotation than all the energy than our sun puts out.” Personally, Ransom has discovered nearly 100 of them.