Where did the Moon come from?

By J. Richard Gott The standard theory for the origin of the Moon is that a Mars-sized planet (named Theia) collided with the Earth about 4.5 billion years ago, and that the splash debris formed the Moon. This theory can explain why the Earth and Moon have identical oxygen isotope abundances (as discovered by theRead More

UFOs: Believe or Not?

Global warming. Species extinction. The end of fossil fuels. Without doubt, there are plenty of problems to cause you to sweat and fret if you’re concerned about our planet’s near-future. But how about adding this to your plate: alien invasion. Sure, it happens regularly in the movies, but what if it’s for real. One-third ofRead More

Nanorobots in Your Future

An exciting revolution in health care and medical technology looms large on the horizon. Yet the agent of change is microscopically small, and will be made possible by nanotechnology. Nanotechnology is the engineering of molecularly precise structures and, ultimately, molecular machines. The prefix nano- refers to the scale of these constructions. A nanometer is one-billionthRead More

Hunting for ET

It is an impressive fact, and one that would have astounded your grandparents, but astronomers now estimate that our home galaxy the Milky Way sports at least a trillion planets. Thata’s a number not easy to picture, a tally greater than the number of trees in the United States. Most of those unseen worlds areRead More