Viruses have distinctive shapes that could aid the search for them on other planets (Image: Laguna Design/Science Photo Library)
IMAGINE you are from an alien civilisation, tasked with collecting a sample from Earth to take back to your planet to look for signs of life. You will only be able to return a small representative sample, which means you will be collecting a small amount of seawater from your visit to this “pale blue dot”.
In a thimbleful of Earth seawater there will be perhaps 10 million viruses, up to a million microbes and certainly no humans. So it’s only…
