Home Current Events Was it Safe to Go Outside 3.9 Billion Years Ago? Was it Safe to Go Outside 3.9 Billion Years Ago? Add to Calendar Time Zone Converter --Select One-- EST/EDT PST/PDT CET/CEST EET/EEST Location: Share share Mark Harrison from UCLA will present his lecture at 11 a.m. EDT on May 17, 2018, in the Greenewalt Lecture Hall as part of DTM's Weekly Seminar Series.Coffee, tea, and a light breakfast will be served before the lecture, at 10:30 a.m.