Related papers: How far are Extraterrestrial Life and Intelligence…
What is the chance we start a conversation with another civilization like our own? Our technological society produced signals that could be received by other extraterrestrial civilizations, within a sphere around us with a radius of $\sim…
The field of the Search for Extraterrestrial Intelligence (SETI) searches for ``technosignatures'' that could provide the first detection of life beyond Earth through the technology that an extraterrestrial intelligence (ETI) may have…
The question of whether intelligent life exists elsewhere is one of the fundamental unknowns about our Universe. Over the past decade more than 200 extra-solar planets have been discovered, providing new urgency for addressing this question…
It is shown that, contrary to an existing claim, the near equality between the lifetime of the sun and the timescale of biological evolution on earth does not necessarily imply that extraterrestrial civilizations are exceedingly rare.…
The Search for Extraterrestrial Intelligence (SETI) makes certain assumptions which guide all current search programs. To illustrate some, this includes (1) that interstellar flight is not possible (2) that the motivations of interstellar…
Why did the emergence of our species require a timescale similar to the entire habitable period of our planet? Our late appearance has previously been interpreted by Carter (2008) as evidence that observers typically require a very long…
Temporal explanations to the Fermi paradox state that the vast scale of the galaxy diminishes the chances of establishing contact with an extraterrestrial technological civilization (ETC) within a certain time window. This argument is…
Given the very close proximity of their habitable zones, brown dwarfs represent high-value targets in the search for nearby transiting habitable planets that may be suitable for follow-up occultation spectroscopy. In this paper we develop…
In this paper we consider the extent to which a lack of observations from SETI may be used to quantify the Fermi paradox. Building on previous research, we construct a geometrical model to compute the probability of at least one detection…
One of the most fundamental questions in exoplanetology is to determine whether a given planet is habitable. We estimate the relative likelihood of a planet's propensity towards habitability by considering key physical characteristics such…
The detection of exoplanets orbiting other stars has revolutionized our view of the cosmos. First results suggest that it is teeming with a fascinating diversity of rocky planets, including those in the habitable zone. Even our closest…
A new solution to the Fermi Paradox is presented: probes or visits from putative alien civilizations have a very low probability until a civilization reaches a certain age (called the Contact Era) after the onset of radio communications. If…
The ease of interstellar rocket travel is an issue with implications for the long term fate of our own and other civilizations and for the much-debated number of technological civilizations in the Galaxy. We show that the physical barrier…
Giant planets within the habitable zones of the closest several stars can currently be imaged with ground-based telescopes. Within the next decade, the Extremely Large Telescopes (ELTs) will begin to image the habitable zones of a greater…
In this paper we address the cosmic frequency of technological species. Recent advances in exoplanet studies provide strong constraints on all astrophysical terms in the Drake Equation. Using these and modifying the form and intent of the…
Earth's future detectability depends upon the trajectory of our civilization over the coming centuries. Human civilization is also the only known example of an energy-intensive civilization, so our history and future trajectories provide…
Over two hundred years ago Capt. James Cook sailed up Whitsunday Passage, just a few miles where we now sit, on a voyage of astronomical observation and discovery that remains an inspiration to us all. Since the prospects of our visiting…
The Drake equation has been used many times to estimate the number of observable civilizations in the Galaxy. However, the uncertainty of the outcome is so great that any individual result is of limited use, as predictions can range from a…
The goal of finding and characterizing habitable planets in other solar systems represents one of humanity's greatest scientific challenges. NASA and ESA have initiated studies of missions that could accomplish this goal within the next ten…
The Great Filter interpretation of Fermi's great silence asserts that $Npq$ is not a very large number, where $N$ is the number of potentially life-supporting planets in the observable universe, $p$ is the probability that a randomly chosen…