Scientists have long held that many of the important compounds and elements that make life possible on Earth arrived here after the planet was formed and was orbiting the sun. These molecules came via meteorites and comets, it was thought, from the colder regions beyond Jupiter. But in a challenge to that long-accepted view, a …
Continue reading "New Insights Into How Earth Got Its Nitrogen"
When our sun was young, it was significantly less luminous and sent out significantly less warming energy than it does now. Scientists estimate that 4 million years ago, when the sun and our solar system were 500 million years old, the energy that the sun produced and dispersed was about 75 percent of what it …
What started as a stunning announcement that the chemical phosphine -- a known byproduct of life -- had been found in the clouds of Venus and could signal the presence of some lifeform has now been strongly critiqued by a number of groups of scientists. As a result, there is growing doubt that the finding, …
Long before there was an Earth, asteroids large and small were orbiting our young sun. Among them was one far enough out from the sun to contain water ice, as well as organic compounds with lots of carbon. In its five billion years or so as an object, the asteroid was hit and broken apart …
One of the enduring puzzles of our planet is why it is so wet. Since Earth formed relatively close to the sun, planetary scientists have generally held that any of the water in the building blocks of early-forming Earth was baked out and so was unavailable to make oceans or our atmosphere. That led to …
Continue reading "An “Elegant” New Theory on How Earth Became a Wet Planet"
Deep inside the rocky planets of our solar system, as well as some solar system moons, is an iron-based core. Some, such as Earth's core, have an inner solid phase and outer molten phase, but the solar system cores studied so far are of significantly varied sizes and contain a pretty wide variety of elements …
This column was written for Many Worlds by Michael L. Wong and Stuart Bartlett. Wong is a postdoctoral research associate at the University of Washington's Astronomy and Astrobiology program and is a member of NASA's Nexus for Exoplanet System Science (NExSS) initiative as part of the university's Virtual Planetary Laboratory team. Bartlett is a postdoctoral …
Continue reading "Thinking About Life (or Lyfe) Through The Prism of “Star Trek”"
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"
Change is the one constant in our world-- moving in ways tiny and enormous, constructive and destructive. We're living now in a time when a rampaging pandemic circles the globe and when the climate is changing in so many worrisome and potentially devastating ways. With these ominous changes as a backdrop, it is perhaps useful …
Continue reading "Everything Changes: The Rise and Fall of the Northern Ocean of Mars"
By now, the coronavirus is an all too familiar menace to most of the peoples of the world. How it is spread, the symptoms of the disease, the absolute necessity of taking precautions against it -- most people know something about the coronavirus pandemic. But the question of what a virus actually is, what are …
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