Hi folks,

I've just read an article on where they write
My 5 questions:
*Where is an eastern/western part at a pole? (I know about the south/north "issue")
*As I am living in Europe: Is for the americans Asia now in the east or in the west? (I believe they have "america-centered" maps there. Or am I wrong???)
*And BTW who sets the 0-meridian at another celestial object (like Mars, the gas-giants or even the sun)???
*When I look for instance at the moon with the unaided eye from the northern hemisphere on earth - what is to the left hand side of the moon: east or west? Is it to see as an astronaut or is my local east/west-thing valid?
*What about tilted planets? Uranus for instance, Venus,....????

Many questions - hope someone can help.
Cheers.


Didi

Eastern Antarctica is the Antarctic portion facing the Indian ocean.

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maybe looking at a map where Australia is on the east side, so is that portion of Antarctica.

You have to remember that while A does contain the south pole, it is a decent sized continent and extends up to about 70degrees Latitude. Thus, there are places where you can look east and see land.

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It would be the part betweeen 180 degree and 360 degree with the north up based on the meridian of origin.

I believe you are wrong. It's called east and far east based on European legacy that dates back centuries ago. I am in Canada and to me, Asia is clearly West And there are no "america-centered" maps that I know of. It they exist, they are wrong too. Maps should be centered upon Greenwich.

Good question, I am not sure but am certain someone on this board knows.

Since the Moon always presents the same side to the earth, it's largely rethorical. Again it would be based on where Meridian 0 is located, in this case, it goes through crater Bruce

On Mercury, the prime meridian is defined to be 20 degrees away from the crater Hun Kal (a name that means 20 in the Mayan language). Positive longitude is east of Hun Kal and positive latitude is toward Planitia Borealis.

The prime meridian on Venus passes through the crater Eve in Alpha Regio. Positive longitude is toward Thetis Regio and positive latitude is toward the Maxwell Mountains.

On the Earth, geographic coordinates are used. As stated earlier, the prime meridian passes through Greenwich. Positive longitude is toward Asia and positive latitude is toward the Arctic.

Areographic coordinates are used on Mars. The prime meridian passes through the crater Airy-O. Positive longitude is toward Syrtis Major and positive latitude is toward Acidalia.

Jupiter has several coordinate systems because different latitudes rotate at different rates. Scientific Astronomer uses System II coordinates, based on the mean atmospheric rotation of the north and south equatorial belts. Positive latitude is in the opposite hemisphere away from the Great Red Spot.

Saturn, Uranus, and Neptune also have several coordinate systems. This package uses the System III coordinates, based on the rotating magnetic field.

In the case of the Galilean moons, Io, Europa, Ganymede, and Callisto, a coordinate system similar to selenographic coordinates on the Moon is used. The prime meridian passes through the mean center of the moon's disk as it faces Jupiter.

source

Hope all this helps

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Mantiss covered just about everything. I would guess that the IAU defines the coordinate system on astronomical objects, but they probably just pass through recommendations by whomever first discovered/mapped the object.

It's no harder to define an eastern region in a polar region than it is to define an eastern region of a symmetrical sphere like Earth. You pick a line and call it the prime meridian. From there, east is east and west is west, and they meet again at the other side.

REPORT OF THE IAU/IAG WORKING GROUP ON CARTOGRAPHIC
COORDINATES AND ROTATIONAL ELEMENTS OF THE PLANETS
AND SATELLITES: 2000 (PDF)

They got smarter about coordinate systems for planets after Earth. Everything is noted as degrees west of the prime meridian, so they don't have to deal with negative longitudes. Guiding principles:

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I think that may be Cassiopeia's point. You can do that at every longitude in A, whereas that is not true in, for instance, Virginia.
That would imply that Europe is mostly in the Eastern Hemisphere, right? Is that the usual meaning of Eastern Hemisphere? I mean, when the term is used at all?

If you narrow it down to a mathetical point, then sure, otherwise there is always bound to be a left (West) and a right (East) to your prime meridian joining both poles, even if it's only millimeters before you come full circle

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Wikipedia: Eastern hemisphere

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Unusual, yes, but why wrong? It's completely arbitrary - the earth is a sphere (for the purposes of this discussion) and there's no natural centre point for a two-dimensional map. Centering on Greenwich (actually the equator due south of Greenwich) is convenient because it's easy to show all the major land masses without breaking them up, but there's nothing inherently "right" about it.

I don't think I know of any maps that are centred on north america... Most I've seen are centered on the atlantic ocean...or, well, probably the prime meridian.

Though sometimes you see Kamyatcha or whatever it is sticking out on the west side of the map.

Wrong as not being centered on the Prime meridian. I mean you could also have a map centered on Iceland, with odd deformation in whatever projection you use if you make that the 0,0 point. Just like in every things, it is good to have global standards for some things, and maps need that too

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OK, I'll buy that. What are the western nations, then?

Maps.com: North America-centered map

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Often: original and descendant nations of the western part of the Old World -- Western and Central Europe and offspring.

Wikipedia: Western world

Geography and politics use the east/west notions differently and inconsistently. A lot has changed over time without labels being changed to match.

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