Video of a Green Flash
Many think it is just a myth . Others think it is true but its cause isn't known. Adventurers pride themselves on having seen it. It's a green flash from the Sun . The truth is the green flash does exist and its cause is well understood. Just as the setting Sun disappears completely from view, a last glimmer appears startlingly green . The effect is typically visible only from locations with a low, distant horizon, and lasts just a few seconds. A green flash is also visible for a rising Sun , but takes better timing to spot. A dramatic green flash was caught on video last month as the Sun set beyond the Ligurian Sea from Tuscany , Italy . The second sequence in the featured video shows the green flash in real time, while the first is sped up and the last is in slow motion . The Sun itself does not turn partly green -- the effect is caused by layers of the Earth's atmosphere acting like a prism . Discovery + Outreach: Graduate student research position open for APOD