Walter H. Haas (1917–2015)

Amateur astronomy has lost a true pioneer, a keen observer who founded the worldwide Association of Lunar and Planetary Observers.

Sometimes astronomy advances thanks to group efforts and sometimes due to the perseverance of a single individual. In the passing of Walter Haas on April 6th, we have lost someone who excelled at both. He died at age 97 of natural causes in Las Cruces, New Mexico, where he had lived for decades.

Haas devoted his entire life to the study of the Moon and planets. Growing up in tiny New Waterford, Ohio, Haas showed an early interest in astronomy that blossomed after spending a summer in Jamaica assisting the renowned planetary observer William H. Pickering. "Pickering, an advocate of a geologically active Moon, had a profound influence on Walter's early thinking," notes S&T Contributing Editor Tom Dobbins. Only 17 at the time, Haas returned to earn an undergraduate degree at Mount Union College in Ohio, where he spent countless nights observing with the school's 10-inch Saegmuller refractor.

At a time when professional astronomers held little regard for amateur observers beyond their meteor and variable-star reports, Haas changed the paradigm. First, he published (in 1938, at age 21) his in-depth observations of brightness changes around major lunar craters. Then, four years later, he followed with a four-part, 76-page opus titled "Does Anything Ever Happen on the Moon?" that appeared in the Journal of the Royal Astronomical Society of Canada. These became the opening salvo in a lifelong quest "to arouse interest in a neglected branch of astronomy."

After World War II, Haas taught mathematics at the University of New Mexico in Albuquerque and crunched the numbers at White Sands Missile range before ending up at New Mexico State University in Las Cruces. He remained there from 1954 until his retirement in 1983.

His passion for solar-system observing never waned, and he typically devoted 500 hours per year to observing the Moon. On March 1, 1947, while still at UNM, he dispatched a self-produced 6-page newsletter titled The Strolling Astronomer. Haas already envisioned this simple missive becoming something bigger: it was subtitled "Association of Lunar and Planetary Observers" and branded with "Volume 1, Number 1." By the second issue, a month later, the budding ALPO had grown to 41 members. Within six years, the association boasted 350 members from all around the world.

Kind, gentle, and patient, Haas was nonetheless unfailingly meticulous and objective when observing — and he expected the same rigor of others, especially those who hoped to have their observations published in The Strolling Astronomer. Some of these contributors went on to careers in astronomy and planetary science in particular. "Walter Haas influenced generations of observers," notes longtime friend and science writer Trudy E. Bell, who proudly notes that her first article (aside from those in campus newspapers) appeared in the ALPO journal's June 1970 issue.

Meanwhile, the breadth and influence of ALPO itself flourished under Haas's leadership. More critically, the heightened visibility of amateur lunar and planetary observations paved the way for enduring professional-amateur collaborations (particularly in planetary studies) that continue today.

So does The Strolling Astronomer (now better known as the Journal of the Association of Lunar and Planetary Observers), the most recent issue of which includes articles on observing comets with giant binoculars and a review of claims for a dense atmosphere around Jupiter's moon Io.

Haas retired as ALPO's Executive Director in 1985 but continued to serve on its Board of Directors. In fact, notes ALPO's Matthew Will, Haas continued to assist his successor, Ken Poshedly, in the proofing and fact checking papers submitted to the journal until about seven or eight years ago. And he kept observing with his trusty 12½-inch Newtonian reflector, typically a couple of times per week, until being sidelined by a broken hip in 2004 (suffered after observing that year's transit of Venus).

Although in failing health recently, Haas remained mentally sharp. "Many of us owe an immeasurable debt of gratitude to Walter for shaping lunar and planetary astronomy for what it has evolved into today," reads the notice on ALPO's website.

Let's hope that, in the not-too-distant future, the current generation of planetary scientists finds a suitable crater on the Moon to bear the name Haas.