That dome, which will eventually house a 16-inch telescope, could be considered the cherry on top of the college's astronomy sundae.
Mt. SAC already houses a planetarium and has a "very strong" astronomy program, but the new observatory will take it to the next level, said Associate Dean of Natural Science Matt Judd.
"It's going to allow (students) to do some first-class research," Judd said.
The shiny metal dome, which can easily be seen from motorists passing by the campus, will also be an obvious reminder to the surrounding community of what Mt. SAC has to offer, Judd said.
"It really helps raise the awareness," he said. "This, people are going to see."
To get the dome in place Friday morning, the crew operating the crane had to perform some unusual maneuvers - a "blind lift" - Judd said.
The meant the crane was located on one side of a nearby building, reached over that building, grabbed the dome, and lifted it into place without the crane operator being able to see a thing.
"We were a little nervous," Judd said. "It was pretty cool, though."
School officials were a bit worried that stormy weather would affect the lift, but Judd said the wind was calm, and rain was negligible.
"Everything fell into place," he said.
The observatory won't be functional until sometime in late January, but the placement of the astronomy dome marks a significant step in a project five years in the making, Judd said.
Once completed, the observatory will not only allow students to look at more distant celestial objects, it will be connected to a network that can beam the images right into their classrooms.
The observatory will also be regularly opened to the public for viewing events, Judd said.
"This is going to be a lot of fun for us," he said.
Students are eager to use the telescope, according to Heather Jones, director of the Mt. SAC planetarium.
Thomas Harmonson, an 18-year-old animation student, is one of them. He said the telescope "says great things about" Mt. SAC.
"I'm actually in the astronomy class, so I'm really excited," Harmonson said.
The observatory is still a construction site, but Jones said it's "inspiring" to see.
"It's going to be a beautiful telescope," she said.