Expert: Ed - 11/8/2005

Question
Dear Ed,

The other experts here could not answer my question either. But I've sort of found something myself that I have "PSed" here incase u wanna give it a read. But before that I'd like to ask another question.

Lately most of the questions I send to allexperts.com are left without an answer. I mean all I get is that this question is outside their experties. Could u please introduce me to another site about astronomy that I could ask my qestions there?

Nevertheless I'd like to let you know that I have never seen a website cooler and more useful than all experts.com

Thank you,
Leila

PS: Well here is what I found:

The unexpected observation was done by Compton Gamma Ray Observatory (CGRO) in 1997. It was supposed to map the Galaxy in gamma ray vision. During this observation the Oriented Scintillation Spectrometer Experiment OSSE equipment on the CGRO detected a "fountain" of 0.5 MeV gamma rays emerging from the centre of the Milky Way.

This amount of energy reminded astronomers of the matter-antimatter annihilation, during which a positron and an electron coincide, annihilate each other, and release two gamma ray photons with energy of 0.511 MeV. This exactly equals the mass of an electron completely converted to energy [E = mc^2]. And this is how astronomers are sure that the mysterious cloud above the centre of the Galaxy is made of positrons (antimatter).


Answer
Leila,

I've been thinking of stopping my AllExperts participation, actually, as much fun as it has been for me.  I can usually help kids with their homework, etc, but when things get too hardcore I apparently can't always help much.  Oh Lord, am I an astronomy lightweight?!?!  No!  God no!  Arrrrrghhh....

There are other services online.  Cornell has a good one:
http://curious.astro.cornell.edu/

So does Goddard at NASA.  This one is much more hardcore than AllExperts.
http://imagine.gsfc.nasa.gov/docs/ask_astro/ask_an_astronomer.html

I hope this is helpful.  Sorry I haven't been able to answer all your questions, although I have enjoyed struggling with them, because even if I can't quite help, the questions are intriguing.

Best wishes, and Keep Looking Up!
--Ed