How to approach finding life on other worlds will continue to be a challenging issue, but how useful that even as we work out strategies for studying exoplanet atmospheres, we have planets we can actually reach right here in our own Solar System. And if the hunt for life has turned up empty thus far on Mars, we can keep searching there even as we consider the exotic possibility of life in the clouds of Venus. We've looked at Venus Life Finder before in these pages. This series of missions is now known as Morning Star, all designed to probe the clouds for signs of a kind of life that would have to endure the most hellish conditions we can imagine. In today's post, Alex Tolley examines the Morning Star Missions and how they might proceed, depending on the results of that all important first sampling of the atmosphere. by Alex Tolley “To boldly seek life, where no terrestrial life has gone before” The “Morning Star Missions” (formerly Venus Life Finder) group had previously outlined...

Two new techniques for examining interesting SETI signals come into view this morning, one out of Breakthrough Listen work at UC-Berkeley, the other from researchers working with the Five-hundred-meter Aperture Spherical radio Telescope (FAST), the so-called ‘Heaven’s Eye’ instrument located in southwest China. In both cases, the focus is on ways to screen SETI observations from disruptive radio frequency interference (RFI), which can appear at first glance to flag a signal from another star. The Chinese work relies upon FAST’s array of receiving instruments, each acting as a separate ‘beam’ to cover slightly different portions of the sky. FAST’s currently operational L-band receiver array consists of 19 beams, to which researchers led by Bo-lun Huang (Beijing Normal University) apply a technique called MultiBeam Point-source Scanning (MBPS). Here the instrument scans the target star sequentially with different beams of the instrument, setting up the possibility of cross-verification...

If we ever thought it would be easy to tell whether a planet was 'habitable' or not, Stephen Dole quickly put the idea to rest when he considered all the factors involved in his study Habitable Planets for Man (1964). In this second part of his essay on habitability, Dave Moore returns to Dole's work and weighs these factors in light of our present knowledge. What I particularly appreciate about this essay in addition to Dave's numerous insights is the fact that he has brought Dole's work back into focus. The original Habitable Planets for Man was a key factor in firing my interest in writing about interstellar issues. And Centauri Dreams reader Mark Olson has just let me know that Dole appears as a major character in a novel by Harry Turtledove called Three Miles Down. It's now in my reading stack. by Dave Moore In Part I of this essay, I listed the requirements for human habitability in Stephen Dole’s report, Habitable Planets for Man. Now I’ll go over what we’ve subsequently...

Dave Moore is a Centauri Dreams regular who has long pursued an interest in the observation and exploration of deep space. He was born and raised in New Zealand, spent time in Australia, and now runs a small business in Klamath Falls, Oregon. He counts Arthur C. Clarke as a childhood hero, and science fiction as an impetus for his acquiring a degree in biology and chemistry. Dave has kept up an active interest in SETI (see If Loud Aliens Explain Human Earliness, Quiet Aliens Are Also Rare) as well as the exoplanet hunt. In the essay below, he examines questions of habitability and how we measure it, issues that resonate in a time when we are preparing to evaluate exoplanets as life-bearing worlds and look for their biosignatures. by Dave Moore In this essay I’ll be examining the meaning of the word ‘habitable’ when applied to planetary bodies. What do we mean when we talk about a habitable planet or a planet’s habitability? What assumptions do we make? The first part of this essay...

SETI’s task challenges the imagination in every conceivable way, as Don Wilkins points out in the essay below. A retired aerospace engineer with thirty-five years experience in designing, developing, testing, manufacturing and deploying avionics, Don is based in St. Louis, where he is an adjunct instructor of electronics at Washington University. He holds twelve patents and is involved with the university’s efforts at increasing participation in science, technology, engineering, and math. The SETI methodology he explores today offers one way to narrow the observational arena to targets more likely to produce a result. Can spectacular astronomical phenomena serve as a potential marker that could lead us to a technosignature? by Don Wilkins Finite SETI search facilities searching a vast search volume must set priorities for exploration. Dr. Jill Tarter, Chair Emeritus for SETI Research, describes the search space as a “nine-dimensional haystack” composed of three spatial, one temporal...

Finding the right conditions for life off the Earth justifiably drives many a researcher's work, but nailing down just what might make the environment beneath an icy moon's surface benign isn't easy. The recent wave of speculation about Enceladus revolves around the discovery of phosphorus, a key ingredient for the kind of life we are familiar with. But Alex Tolley speculates in the essay below that we really don't have a handle on what this discovery means. There's a long way between 'habitable' and 'inhabited,' and many data points remain to be analyzed, most of which we have yet to collect. Can we gain the knowledge we need from a future Enceladus plume mission? by Alex Tolley  There has been abundant speculation about the possibility of life in the subsurface oceans of icy moons. Europa’s oceans with possible hydrothermal vents mimicking Earth’s abyssal oceans and the probable site of the origin of life, caught our attention now that Mars has no extant surface life. Arthur C...