Free Republic

Earth has officially been joined in its orbit around the Sun by a new trojan asteroid. Named 2020 XL5, this chunk of rock is only the second object of its type ever to have been conclusively identified. Its discovery suggests that perhaps Earth trojans may be more common than we knew, and offers new insights into these mysterious rocks. Like the first trojan, astronomers predict that 2020 XL5 will hang around for at least 4,000 years before zipping off to parts elsewhere. "The discovery of a second Earth trojan asteroid may enhance our knowledge of the dynamics of this elusive...

Astronomy Picture of the Day Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. November 8, 1999 Lunation Credit: António Cidadão Explanation: Our Moon's appearance changes nightly. This slow-loading time-lapse sequence shows what our Moon looks like during a lunation, a complete lunar cycle. As the Moon orbits the Earth, the half illuminated by the Sun first becomes increasingly visible, then decreasingly visible. The Moon always keeps the same face toward the Earth. The Moon's apparent size changes slightly, though, and a...