Comet! — Laurence E. Dahners

"Comet!" is the fifth in a series of near future SciFi/Thrillers whose young heroine Ell Donsaii has a nerve mutation which has rendered her a genius and an athletic phenomenon. In “Comet!” she and her team begin exploring outer space using the wormholes she produced in "Rocket." Unfortunately Comet Hearth-Daster is on a trajectory to strike the Earth. Though it is smaller than the object that wiped out the dinosaurs, it still weighs 300 million metric tons and if it hits it will wipe out civilization and may render the human race extinct.

Excerpt:

Walking to the machine shop to talk to Manuel, Ell passed behind Brian and Fred walking across the room. A shock went through her. Brian had a pistol in his hand! Horrifying images of a disgruntled employee gone wild and shooting people flashed through Ell's mind. She felt herself slipping into the zone. Heart throbbing slowly in her ears she slid up behind Brian and, grasping his index finger with her right hand, plucked the gun from his hand with her left. As she did so she was somewhat relieved to note that his finger had been outside the trigger guard and, as she brought the Smith and Wesson toward herself, to see that the safety was on.
“What the hell!?” Brian shouted as, to him, the gun was ripped out of his grip. He turned wildly to see Ell holding it, eyes laser focused on him. The look on her face, usually so friendly, was deadly fierce. In somewhat of a panic he remembered that -- at the Olympics several years ago -- this girl had taken a weapon away from one of a group of seven hardened terrorists and shot them all!
The popular descriptions he had heard of the episode and about her shooting had been hard to countenance at the time, but now he felt his heart thumping wildly in his chest. Without difficulty, she had ripped the gun out of his hand so quickly that his fingers were stinging. He suddenly had no doubt whatsoever that she could kill him before he could even begin to stop her. His hands slowly went up in surrender. “What?”
Fred found himself stepping away from Brian, more frightened by the unfamiliar and terrifyingly intense young woman in front of him than he would have dreamed possible.
Quietly Ell said, biting the words off one at a time so that her speech would be slow enough to understand, “Why, do, you, have, a, gun?”
Brian waved his hands placatingly, “We're worried about another terrorist application of the rings… That's all... Really!”
Ell aggressively tamped down her zone. She narrowed her eyes. “What?”
“We've been brainstorming things terrorists might do with ports. We got to supposing, ‘what if a terrorist carried a port onto a plane.' He could point the port at someone and have his buddy terrorist back home shoot them through the port!”
Ell said, “Wouldn't work” her voice grating like a steel rasp. Her eyes narrowed, “Why do you have a gun here?”
Fred said, “We were going to try it and find out.”
“Oh my God! Where?!”
“In the dangerous reaction room where we tested the rocket motors.”
“OK, I'll grant you it should be tested, but not with a gun! The math predicts that as the velocity of an object entering a port increases, the energy drawn to keep the portal open increases. At first it should increase so slowly that you hardly notice it but it increases exponentially starting at about…” she looked up at the ceiling, “at twenty two meters per second it should begin to get noticeable.” She looked up again, “At around thirty meters per second a graph of it should be climbing very steeply and at around thirty one meters per second it should approach infinity.”
Fred got a glassy look, “Thirty meters per second…”
Ell said, “Sixty seven miles an hour. Starts climbing at forty nine mph and is infinite around sixty nine mph. A pitcher throws a baseball faster. A bullet would hit the port and turn the port and itself into shrapnel. Test it if you want, but don't have anyone in the room, set it up mechanically.