Geocentric model explanation in terms of the Earth's revolution about the sun. In 1838, astronomer Friedrich Wilhelm Bessel measured the parallax of the star 61 Cygni successfully, and disproved Ptolemy's claim that parallax motion did not exist. This finally confirmed the assumptions made by Copernicus, providing accurate, dependable scientific observations, and conclusively displaying how distant stars are from Earth. A geocentric frame is useful for many everyday activities and most laboratory experiments, but is a less appropriate choice for solar system mechanics and space travel. While a heliocentric frame is most useful in those cases, galactic and extragalactic astronomy is easier if
Iron Mountain Central Historic District Iron Mountain Central Historic District The Iron Mountain Central Historic District is a historic district, broadly located between Fleshiem and C Streets and between Iron Mountain and Stockbridge Avenues in Iron Mountain, Michigan. The district covers the city's central business district and adjacent areas. It is primarily commercial, but also contains the historic county courthouse complex, and school, library, and church buildings. It was listed on the National Register of Historic Places in 2013. Lake Superior Iron Ranges]] A major iron ore deposit was discovered near what is now Iron Mountain in 1878/79; the first ore from the first area