How can amateur astronomers collaborate with professional astronomers?

In 3rd Century B.C., Aristarchus of Samos reasoned he could figure out the size of the Earth based on information available during a lunar eclipse. The ... Since this would violate Hawking's own theorems about general relativity, I assume this means that general relativity must be modified. And since his argument ... Astronomers define this distance as one astronomical unit (AU), a measure that serves as a handy cosmic yardstick. Earth rotates on its axis every 23.9 ... Pyramids are called witz—meaning "mountain"—in the Yucatec Mayan language. From a fixed observation station, Maya astronomers tracked where celestial bodies ... A solar eclipse happens when the Moon passes between the Sun and Earth, casting a shadow on Earth that either fully or partially blocks the Sun's light in some ... A lock () or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites. Home. U.S. Geological ... In this work, we introduce a method which allows studying the relationship between different distances (or similarity) measures defined on the same dataset. One ... Uranus · See this term in other languages. Term and definition status: This term and its definition have been approved by a research astronomer and a teacher. It may further be defined by the portion of the colon ... Please understand that UOAA is a private, nonprofit, advocacy and informational organization. These broad areas include such disciplines as astronomy, chemistry, computer and information science and engineering, geoscience, materials research, and ...