Onene of the last full views of Saturn by the Cassini spacecraft, taken on Oct. 28, 2016. (Ho/AFP/Getty Images)

On July 20, 1969, astronauts Neil Armstrong and Buzz Aldrin bounded across the lunar surface as Michael Collins orbited above. We now sail across our solar system. Rovers gambol on Mars, the Cassini spacecraft just plunged through a gap in the rings of Saturn, and the Voyager spacecraft soars into interstellar space, more than 13 billion miles away, still sending back signals to Earth.

But proposed budgets drastically cut support for telescopes that tell us about the universe’s origins and spacecraft that trace the changes on our home planet. And the United States has stood on the sidelines as nations across the world develop the next generation of land-based optical observatories.

Rarely has there been a more exciting and promising time for space science. Telescopes pointing deep into space detect thousands of planets orbiting faraway suns. Life may reside in the ocean worlds of the moons of Jupiter and Saturn or be revealed in the ancient history of Mars. Gravitational-wave observatories probe the inner workings of black holes, like the one at the center of our galaxy. We have the opportunity to understand the origins of dark matter and dark energy, which constitute 95 percent of the universe but remain mysterious. The United States has been a remarkable engine of innovation, creating knowledge for the ages and solving society’s problems today. We have the talent and the entrepreneurial spirit to build on our grand history of discovery. We need only the vision and the will.

Thomas F. Rosenbaum, Pasadena, Calif.

The writer, a physicist, is president of the
California Institute of Technology.

Edward C. Stone, Pasadena, Calif.

The writer is a professor of physics at the California Institute of Technology, project scientist for the Voyager mission and former director of the
Jet Propulsion Laboratory.