The electromagnet moves down Interstate 88 in Naperville, Ill., Friday, July 26, 2013 on its way to Fermilab. The electromagnet is 50 feet wide, weighs more than 15 tons and has taken a month to transport 3,200 miles from New York to Illinois. Image: AP Photo, Scott EisenWithout twisting even an eighth of an inch, a 50-foot-wide electromagnet resembling a flying saucer finished an arduous 3,200-mile trip across land and sea this morning, arriving at an Illinois laboratory where it will be used to study blazing fast particles.

Its journey from New York to the Fermi National Accelerator Laboratory near Chicago, however, wasn't so fast. It was more of a meandering $3.5 million road trip, complete with photos as it passed landmarks and a special Twitter hashtag to keep fans appraised.

The 50-ton electromagnet — the largest in the world — crawled along a suburban Chicago interstate during its final leg early this morning, traveling at five to 15 mph while strapped to a specially made eight-axle flatbed truck. A behemoth bumper sticker informed puzzled onlookers that it was "driving discovery in particle physics."

After leaving the Brookhaven National Laboratory in New York in late June, the massive magnet floated down the East Coast into the Gulf of Mexico — where it outran a tropical depression — then up the Mississippi River to Illinois.

From there, it moved at a nearly glacial pace escorted by tow trucks, police vehicles and gawkers who lined the route to take photos. It finally rolled into the lab in Batavia shortly after 4 a.m. today, looking like a spaceship with a glowing underside in the pre-dawn hours, with an "oversize load" sign and a waving American flag.

Along the way, the device couldn't twist more than an eighth of an inch without being permanently damaged. The cost to replace the magnet, which cannot be disassembled, has been estimated at $30 million.

The magnet had to ride out rough weather in Norfolk, Va., and then encountered more bad weather in the Gulf.

"We had to hurry up and get going through the Gulf of Mexico and really have the tugboat pour it on," says Terry Emmert Jr., vice president of Emmert International, which moved the magnet across the country.

Fermilab officials plan to use the magnet in a physics experiment called Muon g-2 and will use it to study subatomic particles.

They're throwing the magnet a welcome home party this afternoon, complete with food, hands-on exhibits and a special group photo.

The magnet is constructed with aluminum and steel by Brookhaven scientists in the 1990s and made with superconducting coils inside.