Forty years after its construction, the Mark Evans Observatory continues to bring
faculty and students closer to the night sky.
Story by RACHEL HATCH
Humankind has long been fascinated with the night sky and the celestial objects that
draw our gaze. The Mark Evans Observatory on Illinois Wesleyan’s campus has offered
a glimpse into that mysterious realm for generations of faculty and students.
As part of Homecoming in October, the University’s Physics Department celebrated four
decades of the observatory with tours, as well as a reception honoring two emeriti
physics professors — Ray Wilson and Lew Detweiler — who helped foster a love of the
stars for generations of students.
“There were three professors who truly represented the backbone of building the Physics
Department,” says current department chair and Professor of Physics Narendra Jaggi.
“Two of them are still with us today. And so we decided to celebrate them.” The third
professor, former department chair Gary Kessler, died in 1995.
“Their impact is unquestionable. Ninety percent of our curriculum is based on what
they created. They brought in most of our department’s equipment, and have been the
linchpin in maintaining it. They have spent a lifetime teaching and fortifying this
department,” says Jaggi.
More than 100 alumni attended the physics events at Homecoming. The number impressed
Jaggi and others in the department. “When we saw what a great impact the department
has made on alumni, it re-energized our longtime goal of improving equipment. The
first priority, of course, is to update the telescope in the observatory.”
Completed in 1970, the Mark Evans Observatory, like space exploration itself, offered
hope in a turbulent time. Even the building of the observatory brought excitement
to campus. On March 18, 1969, astronaut Frank Borman — commander of the Apollo 8 space mission that was the first manned flight to orbit the moon — attended the University
Founders’ Day to lay the observatory’s cornerstone and to receive an honorary degree.
“He piloted his own jet into Bloomington,” then-University President Robert S. Eckley
recalled in his memoir, Pictures at an Exhibition: Illinois Wesleyan University: 1968-1986. “He generated more interest and excitement than any other visitor to the campus during
my years at Wesleyan.” Though Borman was not the main speaker for Founders’ Day, Eckley
noted that he “captivated the audience and the campus” by offering a message of hope
during a time when racial tension and war gripped the nation. “For a man who just
returned from circling the moon, nothing was impossible,” wrote Eckley.
The same impetus that brought Borman to the moon also inspired the construction of
the Evans Observatory. Wilson came to Illinois Wesleyan in 1962, five years after
the launching of the Soviet Sputnik satellite that kicked off the race into space
between America and the Soviet Union.
“I was about to go and get my doctorate [in astronomy] at the University of Arizona,”
says Wilson, “and I remember President [Lloyd] Bertholf looking at me and saying,
‘Well, I guess we need to get the observatory working again.’”
Illinois Wesleyan had been home to an observatory since 1894, when University friend
C.A. Behr of Chicago donated an 18.5-inch reflector telescope. Crafted in England
by George Calver, it was ranked as the eighth largest telescope in the United States
at that time.
To house the instrument, the University built a small, decagon-shaped observatory,
named for Behr, which became the third building on the main campus block.
In the 1950s, administrators decided to move the Behr Observatory to allow room for
construction of Shaw Hall. “It was small enough to move with a crane,” says Wilson.
When the time came, movers hoisted the entire building off the ground, thinking the
telescope had been secured. It had not. “The telescope was destroyed — all except
the mirror,” Wilson says.
By the 1960s, the space race had launched more than rockets. Students flooded into
astronomy classes with renewed interest in the science of space. “There was a time
when I was teaching classes of 120 in the auditorium of Sherff Science Hall,” says
Detweiler, who joined Wesleyan’s faculty in 1968. Near the conclusion of his tenure
as IWU president, Lloyd Bertholf agreed that a new building was needed to replace
the badly deteriorated Behr Observatory in order to meet growing student interest
While funds were sought to build the observatory, physics faculty and student Barry
Beaman ’65 set to the task of constructing a new telescope, using the original 1894
mirror. “It was quite a sight,” says Detweiler of the finished product. “Of course,
you needed a ladder to reach the eyepiece because it was so tall.”
One third of the $90,000 needed to construct the new observatory was provided by Nan
Morgan Evans in memory of her late husband, Mark, who had been a longtime member of
Illinois Wesleyan’s Board of Trustees. University funds and federal and foundation
grants paid for the remaining costs.
When it came to locating an architect for the observatory, the University looked to
Mark and Nan Evans’ son, Orme. In his original plan, Evans designed the telescope
base to rest on a pyramid shape that would descend into the lower floors of the three-story
observatory. Later, a consultant suggested creating a column instead of a pyramid,
noting it would be similar to those used on interstate overpasses. The column would
be anchored into the ground under the observatory.
Walking into the first floor of the Evans Observatory today, one can see a large block
of bricks that surrounded that very column. “Takes up a lot of space, doesn’t it?”
says Detweiler, knocking lightly on the dark brick. “It wasn’t supposed to be this
big around.” At one point during construction, Detweiler and Kessler brought a small
telescope to the observatory to test the steadiness of the column. “What bothered
us was not so much that it wobbled, but that it continued to wobble like a pendulum
for about a minute,” he says, waving his hand slowly back and forth to show the movement.
As it turned out, the consultant and the construction crew had not communicated fully,
says Detweiler, leading the crew to construct a column exactly like an interstate
overpass, complete with the flexibility to absorb constant shocks. “Movement on a
highway overpass, good. Movement for a telescope, not so good,” says Detweiler with
a smile. The remedy came with pouring more concrete around the column, expanding the
width of the bottom by six feet.
Truly secure this time, the Evans Observatory opened for classes in the fall of 1970.
Just one year later, instructors were dismayed to discover that the telescope’s mirror
from 1894 was finally seeing wear. “There is a precision process to creating a mirror
for a telescope,” Wilson explains. “Temperature changes can affect it over time, and
slowly render it useless.” The Physics Department applied for a federal grant from
the College Science Improvement Program. The grant, coupled with funds from the University,
enabled the purchase of a new 16-inch Cassegrain telescope for around $16,500 in 1971.
Wilson and Detweiler have noted a fluctuation in class sizes over the years, from
120 students each semester during the height of the space race to a much more personal
20 students today. Each semester, students still march up the narrow spiral of the
metal staircase that leads to the Cassegrain telescope in the Evans Observatory dome.
Professor of Physics Linda French and Assistant Professor Thushara Perera now teach
astronomy classes on campus. “Students really like that experience of seeing the stars
through the telescope,” says French, who noted several students have conducted research
at the observatory that helped propel them to graduate school.
The local community also takes in the view of the night sky through the observatory,
which the department opens to the public during major celestial events. French recalled
when the planet Mars was closer to the Earth than it had been in 60,000 years. “In
just one night more than 400 people viewed the polar caps and markings on Mars through
the telescope,” she says. “There was a line down two flights of stairs and out the
front door. We stayed open until every person had seen the planet, and this continued
for several nights.”
The Physics Department is hoping student and public interest continues with the proposed
improvements to the observatory. “We would like to find the funds to have a new telescope
in place in a few years,” says Jaggi. French noted the current telescope and building
are sorely in need of upgrades. “Things have not really changed in 40 years. Right
now, the dome leaks, and we need to set garbage cans out to catch the rainwater,”
she says. “Our telescope does not record data. These days even amateur telescopes
can talk to computers and download data for comparison. We’d love to have something
like that to demonstrate how technology facilitates our field.”
Jaggi hopes changes would open doors for students. “One can think of a completely
different way to study astronomy,” he said. “Just think, remote access to the telescope
would mean homework is more than performing equations. An instructor could say ‘access
the telescope with your laptop, and point it here.’ There are countless possibilities.”
Possibilities, perhaps, as countless as the stars.
To read about physics student Derrick Rohl ’12 and his research at the Cerro Tololo
Inter-American Observatory, click here.
To visit the website of the University Physics Department, click here.