If you received a core file you could try to use gdb to analyze that core file:
$ gdb eclipse core
## Bunch of stuff printed as gdb loads up
gdb> bt --> the 'bt' command in gdb will print the stack back trace as
best as it can and maybe this will show you something about
why it crashed, you can post the outcome of that for opinions
here if that helps
It will likely be difficult to do much more than that analysis without the specific code that eclipse was built with. Sure you can download the eclipse source, but nothing saying it will match the executable which you're using.
The other thing is that using java to run it is vastly different from running an executable.
Actually: What is eclipse running from? If you give it the "which" command is eclipse somewhere in your system, is it purely an executable file, or is it a symbolic link?
The case may be that it was not intended to be run from the shell as you're doing, even though you have that allowance. Or that it requires arguments and it's poorly constructed so that when you don't give it arguments, it has a crash.