Size and Location of the Ecliptic in 600 BC

Question:  Dear Jeff,
I am researching a point about the Ecliptic.
a) if you could ‘draw’ the actual ecliptic on the earth’s surface, what would be its maximum width ?
b)In 600BC at what place approx. on the North coast of Brazil would the ecliptic enter, and where would it exit, South America ?
Thank you very much.  — William

Answer:  Since the Ecliptic is defined as the plane representing the apparent path of the Sun in the sky, it really does not have a “width”.  As for the place where the ecliptic would enter and exit at a location on the north coast of Brazil in 600 BC, what you are really asking is where the Sun will rise and set as viewed from the north coast of Brazil in 600 BC.  Choosing Fortaleza, Brazil, which has a latitude and longitude of (3.7737° S, 38.5748° W), on January 1, 600 BC the Sun would rise and set at azimuth 114 and 246 degrees.  Remember that azimuth is measured positive east from the north, so the rise azimuth is to the south-east (between azimuth 90 and 180) and the set azimuth is to the south-west (between azimuth 180 and 270).

Jeff Mangum