Question about the obliquity of the ecliptic

  • Context: Undergrad 
  • Thread starter Thread starter plutoisacomet
  • Start date Start date
  • Tags Tags
    Ecliptic
Click For Summary
SUMMARY

The obliquity of the ecliptic, which is the tilt of the Earth's axis at approximately 23 degrees, was determined through various observational methods, including measuring the altitude change of the Sun throughout the seasons. The Earth's axis of rotation can be identified by observing the North Star (Polaris), although it is not perfectly aligned with the polar axis. Early explorers utilized celestial navigation techniques to ascertain their positions, and modern astronomers employ tools like polar alignment scopes for precise alignment with the Earth's rotational axis.

PREREQUISITES
  • Understanding of celestial navigation techniques
  • Familiarity with the concept of axial tilt and its implications
  • Knowledge of basic astronomy, including the significance of Polaris
  • Experience with observational tools like telescopes and polar alignment scopes
NEXT STEPS
  • Research the methods of celestial navigation used by early explorers
  • Learn about the historical development of the concept of axial tilt
  • Study the mechanics of Earth's rotation and its effects on celestial observations
  • Explore the use of telescopes and polar alignment techniques in astronomy
USEFUL FOR

Astronomy enthusiasts, students planning to take astronomy classes, and anyone interested in understanding Earth's axial tilt and celestial navigation techniques.

plutoisacomet
Messages
89
Reaction score
0
Question about the "obliquity of the ecliptic"

Hello guys, I hope I am in the correct forum for this question. If not, then I am sorry.
How was it determined that the Earth was tilted roughly 23 degrees from its orbital plane? Or, how did the current locations/definitions of the north pole, the south pole and the equator come about.
Thanks:
confused:
 
Astronomy news on Phys.org
The poles are the axis of rotation of the earth, the equator halfway in between, and the tilt was determined from that (it is easily measured by measuring the altitude change of the sun with the seasons).
 
Thanks for your quick reply RW. I understand that of which you have explained. I guess my question is how was the Earth's axis of rotation determined.
 
plutoisacomet said:
I guess my question is how was the Earth's axis of rotation determined.
You can see it when you look at the North Star at night. The location of the equator can also be determined by watching the stars and Sun.

Early explorers of the arctic did, in fact, use celestial navigation to figure out where they were. It is actually slightly more complicated than just measuring the altitude of Polaris - Polaris isn't exactly on our polar axis.

My telescope has a handy-dandy polar alignment scope which helps me align it with the Earth's rotational axis to within a tenth of a degree or so. Then using several other methods, I can get even closer than that.
 
Last edited:
I see and thanks for clearing that up for me. I haven't had any Astronomy classes yet but I plan to take several.
Thanks again
 

Similar threads

  • · Replies 13 ·
Replies
13
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 3 ·
Replies
3
Views
4K
  • · Replies 142 ·
5
Replies
142
Views
135K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 3 ·
Replies
3
Views
5K
  • · Replies 8 ·
Replies
8
Views
10K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 42 ·
2
Replies
42
Views
11K
  • · Replies 1 ·
Replies
1
Views
6K