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 Measuring the Distances Between Planets
Name: doug a foster
Status: N/A
Age: N/A
Location: N/A
Country: N/A
Date: 1993 - 1999


Question:
How do scientists measure the size of the other planets and their distances from the earth?


Replies:
Kepler, essentially, did it, and it wasn't simple. The idea is basically that if I know a planet's orbit around the sun, and I know where the planet appears to be at two different positions of the earth in the earth's orbit, then I can figure the distance to the planet by triangulation. Once I kn ow the distance, figuring the size is straight trigonometry based upon the planet's apparent size. It all checks, because the planet's distance from the sun can be calculated from the length of its year.

J Lu



Click here to return to the Astronomy 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
n b