Department of Energy Argonne National Laboratory Office of Science NEWTON's Homepage NEWTON's Homepage
NEWTON, Ask A Scientist!
NEWTON Home Page NEWTON Teachers Visit Our Archives Ask A Question How To Ask A Question Question of the Week Our Expert Scientists Volunteer at NEWTON! Frequently Asked Questions Referencing NEWTON About NEWTON About Ask A Scientist Education At Argonne Sunrise and Sunset Times
Name: Michelle L.
Status: Student
Age: 16
Location: N/A
Country: N/A
Date: February 23, 2003


Question:
Why sunrise and sunset times change each day?



Replies:
Michelle,

The Earth is tilted at an angle of 23 degrees from being vertical (as compared with the orbital plane of the Earth about the Sun).

As the Earth revolves around the Sun during the period of a year, the northern hemisphere is more pointed towards the Sun in summer and more pointed away from the Sun in winter.

So, in summer, the Sun rises north of east and sets north of west, giving it an earlier rise time and a later set time than during the winter when the Sun rises south of east and sets south of west.

Each day, the times of sunrise and sunset change slightly from the day before because of the slight change in where the Sun rises and sets.

David R. Cook
Atmospheric Research Section
Environmental Research Division
Argonne National Laboratory



Click here to return to the Environmental and Earth Science Archives

NEWTON is an electronic community for Science, Math, and Computer Science K-12 Educators, sponsored and operated by Argonne National Laboratory's Educational Programs, Andrew Skipor, Ph.D., Head of Educational Programs.

For assistance with NEWTON contact a System Operator (help@newton.dep.anl.gov), or at Argonne's Educational Programs

NEWTON AND ASK A SCIENTIST
Educational Programs
Building 360
9700 S. Cass Ave.
Argonne, Illinois
60439-4845, USA
Update: June 2012
Weclome To Newton

Argonne National Laboratory