In 1977 astronomers recorded a brief and strange radio transmission that looked like it perhaps had even come from an alien civilization. It was named the Wow! signal – because that’s what astronomer Jerry Ehman wrote on the computer printout upon its discovery. But now a team including Abel Méndez of the University of Puerto Rico at Arecibo have come up with an astrophysical hypothesis.

An oil tanker which was attacked by Yemen's Houthi rebels in the Red Sea last week is still on fire and may be leaking oil, the US Pentagon says. The talk now is of an agreement to salvage the tanker so a crisis may be avoided, but marine ecologist Carlos Duarte of the King Abdullah University of Science and Technology in Saudi Arabia explains how precious ecosystems are at risk.

A meta-analysis of Mediterranean Sea marine species reveals the profound impact of the Messinian Salinity Crisis. Konstantina Agiadi of the University of Vienna tells us how this drastic environmental event resulted in the almost complete evaporation of the Mediterranean Sea roughly 5.5 million years ago and how the resulting changes still influence ecosystems today.

Wildfires that swept across Canada last year are still burning in some parts. A new study has confirmed that they put into the atmosphere a vast amount of burned carbon, over half a billion tonnes. Only China, India and the USA emitted more fossil-fuel based carbon in that period. Brendan Byrne of NASA’s Jet Propulsion Laboratory has been using satellite-based observations to track the carbon release.

Presenter: Roland Pease Producer: Jonathan Blackwell Production Coordinator: Andrew Rhys Lewis

(Image: The Wow! signal represented as "6EQUJ5". Credit: NAAPO)