The city of Frankfort recently became the site of a permanent tribute to two brothers who looked at the night sky and saw a universe far larger than anyone had previously imagined. In October, an Indiana State Historical Marker was installed in front of Frankfort City Hall to honor Vesto Melvin and Earl Carl Slipher, alumni of Indiana University’s College of Arts and Sciences whose work fundamentally reshaped modern astronomy. The location of the marker is particularly poetic, as the building once served as the high school where the brothers first began their academic journeys before moving on to Bloomington.
Vesto Slipher carved out a legacy as one of the most influential observational astronomers of the early 20th century. After becoming the first person to earn a Ph.D. in Astronomy from Indiana University in 1909, he moved to the Lowell Observatory in Arizona. There, his precise measurements of distant galaxies provided the critical evidence needed to establish that our universe is expanding. His pioneering research into interstellar gas and dust eventually led him to serve as the director of the observatory, cementing his place in the annals of cosmology.
While Vesto focused on the furthest reaches of space, Earl Slipher turned his attention to our own cosmic neighborhood. An internationally recognized planetary astronomer and astrophotographer, Earl captured roughly 100,000 images of Mars and other planets over a career spanning five decades. His meticulous documentation of seasonal changes on the Red Planet produced some of the most significant planetary maps of his era, which later proved invaluable to NASA during the planning stages of early missions to Mars.
Catherine A. Pilachowski, chair of the Department of Astronomy at IU Bloomington, noted that the brothers exemplify how groundbreaking discoveries can emerge from humble beginnings. She emphasized that their journey highlights the profound impact of public higher education, showing how the skills they developed in Indiana allowed them to redefine humanity’s place in the cosmos. The new marker stands not only as a recognition of their scientific achievements but as an inspiration for future generations of researchers.
