Not long ago, I attended a memorial service on top of the Greenland ice sheet for a man I did not know. The service was an intimate affair, with only four people present. I worried that I might be regarded as an interloper and thought about stepping away. But I was clipped onto a rope, and, in any case, I wanted to be there.
The service was for a NASA scientist named Alberto Behar. Behar, who worked at the Jet Propulsion Laboratory, in Pasadena, might be described as a twenty-first-century explorer. He didn’t go to uncharted places; he sent probes to them. Some of the machines he built went all the way to Mars; they are orbiting the planet today or trundling across its surface on the Curiosity rover. Other Behar designs were deployed on Earth, at the poles. In Antarctica, Behar devised a special video camera to capture the first images ever taken inside an ice stream. In Greenland, he once sent a flock of rubber ducks hurtling down a mile-long ice shaft known as a moulin. Each duck bore a label, offering, in Greenlandic, English, and Danish, a reward for its return. At least two made it through.
When Behar died, in January, 2015—he crashed his single-engine plane onto the streets of Los Angeles—he was at work on another probe. This one, dubbed a drifter, looked like a toolbox wearing a life preserver. It was intended to measure the flow of meltwater streams. These so-called supraglacial rivers are difficult to approach, since their banks are made of ice. They are often lined with cracks, and usually they end by plunging down an ice shaft. The drifter would float along, like a duck, collecting and transmitting data, so that, by the time it reached a moulin and was sucked in, it would have served its purpose.
Behar was collaborating on the drifter project with a team of geographers at U.C.L.A. After his death, the team carried on with the project, which itself became a kind of memorial. When the geographers picked a supraglacial river to toss the drifters into, they called it the Rio Behar.
I flew up to the Rio Behar in July with several U.C.L.A. graduate students and two drifters. My first glimpse of it was out the helicopter window. Its waters were an impossible shade, a color reserved, in other circumstances, only for Popsicles. That fantastic blue was set against a pure and hardly less fantastic whiteness. “Greenland!” the artist Rockwell Kent wrote, after being shipwrecked in an ice fjord. “Oh God, how beautiful the world can be!”