Astronaut Reid Wiseman has caused a stir on Twitter, posting an eerie photo taken from space showing mysterious green lights just outside Bangkok.

#Bangkok is the bright city. The green lights outside the city? No idea… pic.twitter.com/TDzyin3hK7

— Reid Wiseman (@astro_reid) August 18, 2014

Mr Wiseman, a crew member on the International Space Station, noticed the phenomenon over the Gulf of Thailand and, perplexed, called on the public to explain.

It turns out the explanation is far less exciting than potential alien activity: they’re fishing boats.

According to several respondents on Twitter, the most likely culprits are the local boats that use unusual green LED lights to attract squid.

@erholtzclaw @VictorSuave @astro_reid It would not. Those are fishing boats with green lights for attracting phytoplankton and fish. — Peter Caltner (@PC0101) August 18, 2014

Whatever they are, they’re beautiful.