Associated Press The police mug shot of astronaut Lisa Marie Nowak after her arrest in Florida. Click photo for larger image. More coverage Astronaut charged with attempted murder

Love IS strange.

What would possess a woman to don a diaper and drive 900 miles to confront her lover's other woman?

More to the point, what would make a married mother of three and an accomplished astronaut -- one of only 106 overall active U.S. astronauts and one of only 24 active U.S. women astronauts, according to NASA -- jeopardize and potentially sacrifice her family, her future and her successful career for a love affair?

That was the watercooler question of the day yesterday as news spread that 43-year-old Navy captain and astronaut Lisa Marie Nowak drove from Houston to Orlando early Monday, according to police, to kidnap Air Force Capt. Colleen Shipman, a Patrick Air Force Base engineer who works on space flight-related hardware at Cape Canveral, Fla. Ms. Nowak wore a diaper on the 14-hour drive, so she wouldn't have to stop to use a restroom.

Both Ms. Nowak and Ms. Shipman have been vying for the romantic attentions of unmarried astronaut and Navy Cmdr. Bill Oefelein.

People don't think logically or rationally when their emotions take over, and that's what sometimes leads people to take bizarre and dangerous actions, said Dr. Scott Tracy, an assistant professor of counseling psychology at Pittsburgh's Chatham College.

"Love is an emotion and doesn't have anything to do with how smart you are," Dr. Tracy said. "Really smart, accomplished people fall in love, and we're all at high risk to have broken hearts. Especially at high risk are those who have not experienced that before."

Jacques Boissinot, Associated Press Astronauts William A. Oefelein, left, and Lisa M. Nowak pose for a photo before starting special training under austere conditions at CFB Valcartier in Valcartier, Quebec, Canada, in January 2004. Click photo for larger image.

Wearing a trench coat and a wig, Capt. Nowak confronted Capt. Shipman in a parking lot at Orlando International Airport and shot a burst of pepper spray into her vehicle, police said. With eyes burning, Capt. Shipman was able to drive away and seek help.

"When we are emotionally caught up in another person, sound judgment can become impaired," says John D. Moore, a Chicago-based licensed clinical psychotherapist and author of the book, "Confusing Love with Obsession." "That's not an excuse and not a permission slip to act incorrectly, but this is what can happen when we become attached to another person."

Capt. Nowak, a Discovery Shuttle mission specialist in July, isn't the first accomplished woman to snap when finding herself on the odd side of a love triangle.

In 1980, Jean Harris, headmistress of a Virginia girls school and long-time mistress of "The Scarsdale Diet" Dr. Herman Tarnower, shot him to death in his Purchase, N.Y., home after confronting him about an affair. She was convicted of second-degree murder and pardoned in 1992.

In 2003, Texas dentist Clara Harris was convicted of murder for repeatedly running over her husband with her Mercedes-Benz after confronting him about an affair. She is serving a 20-year sentence and last month was ordered to pay $3.75 million to her late husband's parents as part of a wrongful-death suit.

Now, we have Capt. Nowak.

	KDKA-TV Air Force Capt. Colleen Shipman was the target.

"Here you have someone who, for all intents and purposes, is a wildly successful person professionally," says Mr. Moore, who teaches health sciences and psychology for Chicago's online accredited American Military University. "We sometimes think that this kind of thing only happens with movie stars or lower-functioning people, but the ugly American secret is that many of us have been caught up in a triangle at some point or another.

"The longer we participate in it, the lower our self-esteem becomes, the more angry and resentful we become with the person we're involved with or the other person [in the triangle]."

Fortunately, most people stop before it goes too far.

On his Web site, www.relationshipaddict.com, Mr. Moore outlines the four stages of obsession as the attraction phase, the anxious phase, the obsessive phase and the destructive phase, in which people do things destructive not only to themselves, but to others.

Whether it's pepper-spraying and trying to kidnap a romantic rival, slashing someone's tires, aiming to get someone fired or killing a romantically duplicitous lover -- all are signs of obsession.

"This can include stalking behaviors, either online or in person," he says. "Rarely is it an impulse decision. It is planned out and thought out."

While he can't speak to Capt. Nowak's particular situation, Mr. Moore said some people who get caught up in love triangles have borderline personality disorder, symptoms of which include intense feelings of anger and intense fear of abandonment.

"That's when they might do anything to try to keep [their beloved]," he said. "As someone who is obsessed with another person, this is what may have happened. She wanted to, in one way or another, eliminate or minimize the competition."