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Zamedy
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Does anyone know if there is any internationally agreed method for determining where zero degrees longitude is when mapping other planets etc.?
For some planets, like the gas giants, it's not clear that you could map them in a fashion similar to what has been done on earth, because there are no fixed features or other reference points to use.Zamedy said:Does anyone know if there is any internationally agreed method for determining where zero degrees longitude is when mapping other planets etc.?
D H said:There are ways of writing things in scientific journals and saying things in hallways that indicate that the authors / speakers think their opponents are a bunch of morons without using a single derogatory term
SteamKing said:For some planets, like the gas giants, it's not clear that you could map them in a fashion similar to what has been done on earth, because there are no fixed features or other reference points to use.
Most of the probes sent to other planets in the solar system were designed to photograph these bodies as they flew by. There have been probes sent to the moon, Mars, Venus, and Mercury which went into orbit around those bodies. Because actual exploration of the surface may be impossible or very remote in the future, the concentration of data gathering for those missions was to collect physical data about each body, like whether there was a magnetic field, etc., rather than setting up a surface navigation system.
https://en.wikipedia.org/wiki/Exploration_of_Mercury#Missions
Perhaps in the future, it may be appropriate to devise some sort of mapping convention, but for now, just getting a glimpse of these bodies up close and taking photographs has been sufficient.
In the meantime, you can access Google Mars and Google Moon, which are similar to Google earth.
Your 180 km figure corresponds to roughly six degrees. A minute of arc is 1/60th of a degree. A minute of arc represents about 500 meters on the surface of the Moon. (I wrote "about a minute of arc." The actual discrepancy between Moon ME and Moon PA coordinates is about 860 meters at the surface.)Zamedy said:As for the moon coordinates - it beggars belief that these well-educated logical creatures still can't decide one way or the other.
A minute arc would be about 180km on the surface of the moon - that's quite a hike if they get it mixed up!
D H said:Your 180 km figure corresponds to roughly six degrees. A minute of arc is 1/60th of a degree. A minute of arc represents about 500 meters on the surface of the Moon. (I wrote "about a minute of arc." The actual discrepancy between Moon ME and Moon PA coordinates is about 860 meters at the surface.)
Zero degrees longitude on other planets is the starting point for measuring longitude, similar to the Prime Meridian on Earth. It is a theoretical line that runs from the north to the south pole, passing through the equator at a right angle.
Zero degrees longitude on other planets is determined by the International Astronomical Union (IAU) through a process of mapping and naming features on the planet's surface. The location of the zero degree line is typically chosen to pass through a significant landmark or feature on the planet.
No, zero degrees longitude is unique to each planet. While Earth's zero degree longitude is located at the Royal Observatory in Greenwich, London, the location of the zero degree line on other planets varies based on their own landmarks and topography.
Zero degrees longitude serves as a reference point for measuring longitude and is crucial for navigation and mapping on other planets. It allows scientists and explorers to accurately pinpoint locations and navigate the planet's surface.
Yes, some planets may not have a defined zero degree longitude due to their unique characteristics. For example, Mercury has no defined zero degree line due to its slow rotation, while Venus and Uranus have zero degrees longitude at their poles due to their retrograde rotation.