Killer asteroids

For a while last week, the world was agog at the possibility that Asteroid 1997 XF11 would bash Earth in the year 2028. Then NASA refined the predictions, discovering that it would miss the planet by a comfortable margin of 600,000 miles.

But what if something that big - a bit larger than half a mile across - were to hit us? What would be the result?

It would be bad, says Lynn Jackman, a Salt Lake novelist, very bad. Jackman has carefully researched the results from an asteroid hit for a science fiction book he is completing, The Pytheas Expedition. He devoured books, articles and scientific reports on the subject, accumulating a file of notes as thick as the novel itself.

An asteroid six miles across killed off the dinosaurs. While 1997 XF11 is only one-10th as large, it still could pack the punch of a "hundred gigaton explosion," Jackman said. A gigaton blast is equivalent to the explosion of one billion tons of TNT. "That'll create a 20-mile crater."

You could expect the atmosphere to get oven-hot for a couple of hours. The heat would spark fires at least throughout the hemisphere where it hit. If you were in a shelter, you'd better have food - the dust would block sunlight for several weeks to several months, preventing plant growth.

If the monster hit an ocean, coastal regions will get slammed with tidal waves up to 1,000 feet high. Because of a gigantic splash effect, with water erupting and falling back over and over again, the coasts would be battered by a series of tsunamis.

Would mankind survive? "I think yeah, we could survive it, but it would cause massive damage, on an unprecedented scale," Jackman said. "It could kill billions."

Dying without distress

The public is invited to attend a conference, "Final Plans: Ethical, Legal and Medical Ways to Direct Care at the End of Life," scheduled for Monday, March 23, 8 a.m. to 4 p.m. at the Utah Law & Justice Center in Salt Lake City. The cost is $85, but those who can't afford the fee may get an exemption.

The conference is sponsored by LDS Hospital's Division of Medical Ethics and by the University of Utah School of Medicine. Local and national experts will address questions like Oregon's vote on assisted suicide, what someone can do to avoid what he fears most about death and dying, how health professionals should react to questions about assisted suicide, dying without physical distress and the obligation managed care systems have to the terminally ill.

To register or get further information, call the hospital at 321-1135.

Far-sighted study

The excimer laser can improve vision by reshaping the eye's cornea - but until recently the operation was only available to people who are nearsighted. But now the University of Utah's Moran Eye Center is among 20 sites nationwide carrying out an excimer laser study in which farsightedness is corrected.

In the new operation, a laser is used to steepen the cornea so that light rays converge sharply on the retina. "The operation takes about 15 minutes," said Dr. Thomas E. Clinch, associate professor of ophthalmology and director of Refractive and Corneal Services at the center.

"The procedure has been done for several years in Europe and in other parts of the world. We plan to do about 100 patients in Utah during the study, and then the FDA will analyze the data." He believes the FDA will approve the procedure for general use.

The operation costs $2,100 per eye. Anyone interested in participating in the study may call the center at 585-3937.