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"
The surface of the sun, with each "kernel" or "cell" roughly the size of Texas. The movie is made up of images produced by the Daniel Inouye SolarTelescope in Hawaii. Novel and even revolutionary data and images are also expected from the Parker Solar Probe (which will travel into the sun's atmosphere, or corona) and …
Continue reading "Exploring Our Sun Will Help Us Understand Habitability"
When the the first Star Wars movie came out in 1977, it featured the now-iconic two-sun, "circumbinary" planet Tatooine. At that time astronomers didn't really know if such solar systems existed, with more than one sun and at least one planet. Indeed, the first extra-solar planet wasn't detected until the early 1990s. And the first …
There is no doubt that early Mars had long period of warmer and much wetter climates before its atmosphere thinned too much to retain that liquid H20 on the surface. As we know from the Curiosity mission to Gale Crater and other orbital findings, regions of that warmer and wetter Mars had flowing water …
Candidate exoplanets as seen by TESS in a southern sky mosaic from 13 observing sectors. (NASA/MIT/TESS) NASA’s Transiting Exoplanet Survey Satellite (TESS) has finished its one year full-sky observation of Southern sky and has found hundreds of candidate exoplanets and 29 confirmed planets. It is now maneuvering its array of wide-field telescopes and cameras to …
Topographical map of Venus by NASA's Magellan spacecraft (1990 - 1994). Color indicates height. (NASA/JPL/USGS) How many habitable worlds like our own could exist around other stars? Since the discovery of the first exoplanets, the answer to this question has seemed tantalizingly close. But to estimate the number of Earths, we first need to understand …
The newest space telescope in the sky -- NASA's Transiting Exoplanet Survey Satellite, TESS -- has been searching for exoplanets for less than a year, but already it has quite a collection to its name. The TESS mission is to find relatively nearby planets orbiting bright and stable suns, and so expectations were high from …
Continue reading "Exoplanets Discoveries Flood in From TESS"
The quest to find habitable -- and perhaps inhabited -- planets and moons beyond Earth focuses largely on their location in a solar system and the nature of its host star, the eccentricity of its orbit, its size and rockiness, and the chemical composition of its atmosphere, assuming that it has one. Astronomy, astrophysics, cosmochemistry …
Continue reading "The Interiors of Exoplanets May Well Hold the Key to Their Habitability"
For years now, finding planets in the habitable zones of their host stars has been a global astrophysical quest and something of a holy grail. That distance from a star where temperatures could allow H20 to remain liquid some of the time has been deemed the "Goldilocks" zone where life could potentially emerge and …
Continue reading "Exoplanets With Complex Life May Be Very Rare, Even in Their “Habitable Zones”"
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"
Many Worlds 