When the word "virus" first came into use, it was as a "poison" and “a very small disease-causing agent.” While the presence of viruses was theorized earlier, they were not fully identified until the 1890s. So from their earliest discovery, viruses were synonymous with disease and generally of the ghastly epidemic type of disease …
Continue reading "Viruses, the Virosphere and Astrovirology"
When especially interesting new planets are discovered in the cosmos, scientists around the world begin the process of identifying their characteristics -- their orbit, their mass and density, their composition, their thermal properties and much more. It's all part of a drive that seems to be innate in humans to learn about the workings of …
Anthony Del Genio started out his career expecting to become first an engineer and then a geophysicist. He was in graduate school at UCLA and had been prepared by previous mentors to enter the geophysics field. But a 1973 department-wide test focused on seismology, rather than fields that he understood better, and his days as …
Continue reading "Using Climate Science on Earth to Understand Planets Beyond Earth"
Seldom does one rock outcrop get so many visitors in a day, especially when that outcrop is located in rugged, frigid terrain abutting the Greenland Ice Sheet and can be reached only by helicopter. But this has been a specimen of great importance and notoriety since it appeared from beneath the snow pack some eight …
Continue reading "On The Frontier Of The Hunt For Signs Of Life On Early Earth And Ancient Mars"
Paleontology has for centuries worked to understand the distant past by digging up fossilized remains and analyzing how and why they fit into the evolutionary picture. The results have been impressive. But they have been limited. The evolutionary picture painted relies largely on the discovery of once hard-bodied organisms, with a smattering of iconic finds …
Continue reading "Exploring Early Earth by Using DNA As A Fossil"
It is my very good fortune to report that I have just arrived in Greenland for quite a scientific adventure. Over the next days, a group of scientists (along with me and NASA videographer Mike Toillion) will be traveling to the site of the stromatolite that might, or might not, be the oldest remains …
Did you know that many bacteria -- some of the oldest lifeforms on Earth -- can talk? Really. And not only between the same kind of single-cell bacteria, but back and forth with members of other species, too. Okay, they don't talk in words or with sounds at all. But they definitely communicate in …
A look inside the planet simulator in the Origins of Life laboratory at McMaster University. Within this chamber, the origins of life can be explored on different worlds (McMaster University). Have you ever wondered if you could kick-start life on another planet? In the Origins of Life laboratory at McMaster University in Canada, there is …
Virtually every definition of the word "life" includes the capability to undergo Darwinian evolution as a necessary characteristic. This is true of life on Earth and of thinking about what would constitute life beyond Earth. If it can't change, the thinking goes, then it cannot be truly alive. In addition, evolutionary selection and change occurs …
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When scientists speculate about possible life on Mars, they generally speak of microbial or other simple creatures living deep below the irradiated and desiccated surface. While Mars long ago had a substantial period that was wetter and warmer when it also had a far more protective atmosphere, the surface now is considered to be …
Continue reading "How Creatures End Up Miles Below the Surface of Earth, and Maybe Mars Too"
Many Worlds 