Apple - How to find a cause of a Kernel Panic message, or BSoD?

The kernel panic text is added to the log after you restart the computer, assuming that you did not reset PRAM (the kernel panic text is stored in PRAM until you restart). In Mac OS X v10.6, the logs are located in in /Library/Logs/DiagnosticReports. In Mac OS X v10.5, the logs are located in /Library/Logs/PanicReporter (source)

If you cannot find these files, or they contain no information on the kernel panic, then there is likely something wrong with the hardware of the computer. Running a system diagnostic or visiting the genius bar is probably your next step.

If you are really interested in attempting to resolve the issue yourself, you might find this guide to resolving OS X kernel panics helpful.

All panic and sleep failure logs are stored in /Library/Logs/DiagnosticReports since Mojave, in Kernel-%DATE%-.panic files.

It is indeed a kernel panic, the default behaviour is to display this screen rather than printing anything useful unfortunately.

If there's nothing in the system logs in console, then you can try booting your Mac in verbose mode. Hold Cmd + V while powering it on, you'll know when you get it right when loads of text gets written to screen instead of the normal spinning indicator.

Verbose mode causes kernel panics to log information to the screen rather than just showing the "you need to restart your computer" instruction. If you get another panic this should at least give you more specific details about the problem.

Apple's official troubleshooting guidelines recommend a safe boot and then a reboot. That support page also includes advanced troubleshooting information such as the location of the panic logs.