How ancient microbes survived in a world without oxygen has been a mystery. Scientists discovered a living microbial mat that uses arsenic instead of oxygen for photosynthesis and respiration.
The discovery of phosphine in the acidic clouds of Venus can't be explained by any known chemical or geological processes.
Everyone knows the Great Barrier Reef is in peril. But a continent away, Western Australia's Shark Bay is also threatened by marine heatwaves that could alter this World Heritage ecosystem forever.