Rather like a swollen river overflowing its banks, the story of water on Mars keeps on rising and spreading in quite unpredictable ways. While the planet is now inarguable parched -- though with lots of polar and subsurface ice and, perhaps, some seasonal surface trickles -- data from the Curiosity rover, the Mars Reconnaissance …
Continue reading "Ancient Mars Water. Ever More of It, and Flowing Ever Longer on the Surface"
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 …
Continue reading "A New and Revelatory Window Into Evolution on Earth"
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"
If there was a simple meaning of the often-used scientific term “emergence,” then 100-plus scientists wouldn’t have spent four days presenting, debating and not infrequently disagreeing about what it was. But as last month’s organizers of the Earth-Life Science Institute’s “Comparative Emergence” symposium in Tokyo frequently reminded the participants, those debates and disputes are …
The question of how life-essential elements such as carbon, nitrogen and sulfur came to our planet has been long debated and is a clearly important and slippery scientific subject. Did these volatile elements accrete onto the proto-Earth from the sun's planetary disk as the planet was being formed? Did they arrive substantially later …
This story was written by Nicholas Siegler, Chief Technologist for NASA’s Exoplanet Exploration Program at the Jet Propulsion Laboratory with the help of doctoral student Markus Gogouvitis, at the University of New South Wales, Australia and Georg-August-University in Gottingen, Germany. This past July I joined a group of geologists, geochemists, microbiologists, and fellow …
Continue reading "Time-Traveling in the Australian Outback in Search of Early Earth"
An essential characteristic of life is that it evolves. Whether on Earth or potentially Mars, Europa or distant exoplanets, we can assume that whatever life might be present has the capacity and the need to change. Evolution is intimately tied to the origin-of-life question, which this column often explores. Having more answers regarding how life …
Continue reading "Piecing Together The Narrative of Evolution"
We all know that cut diamonds sparkle and shine, one of the great aesthetic creations from nature. Less well known is that diamonds and the bits of minerals, gases and water encased in them offer a unique opportunity to probe the deepest regions of our planet. Thought to be some of the oldest available materials …
In my recent column about The Northern Lights, the Magnetic Field and Life, I explored the science and the beauty of our planet's aurora borealis, one of the great natural phenomenon we are most fortunate to see in the far North (and much less frequently in the not-quite-so-far North.) I learned the hard way that …
May I please invite you to join me in the presence of one of the great natural phenomena and spectacles of our world. Not only is it enthralling to witness and scientifically crucial, but it’s quite emotionally moving as well. Why? Because what’s before me is a physical manifestation of one of the primary, but …
Continue reading "The Northern Lights, the Magnetic Field and Life"
Many Worlds 