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 Number Of Planets 
Name: Unknown
Status: Other
Age: N/A
Location: N/A
Country: N/A
Date: Prior to 1993
Question:
How many known planets are there, inside and outside the solar system? I have read in Astronomy magazine that at least 2 planets were discovered around a pulsar (I do not know where) and that perhaps a 10th planet lies past Pluto. Any more I do not know about?


Replies:

I have not heard of any good hard evidence for any planets other than the usual nine.

John Hawley
Update - March 2011
As 2011, there are officially eight planets in our Solar System. Pluto, common thought of as the ninth planet, is officially listed as a dwarf planet. There are many dwaft planets in our solar system, Ceres, Pluto, Haumea, Makemake, and Eris.

There have also been planets discovered outside of our solar system, thoughI do not have a count on them at the present time.

PG

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