There are many science-related events going on in Second Life (SL) these days. I don’t know why, but these things seem to come in waves. There must be about 30 science-related events in SL this fortnight. A good place to find out about all those events is on the calendar at the SL Science Center wiki.
That calendar is a public Google Calendar, so you can subscribe via RSS or iCal – just see the above link for the details.

NPR’s Science Friday is in SL every Friday from 7-9pm GMT, at the sim named ‘Science School’.