Chris D. Impey

• B.Sc., Ph.D.
• Professor at University of Arizona

This Video features NASA Space Shuttle films of extraterrestrial life, that escaped NASA's censors; and documents that extraterrestrial life forms engage in complex behaviors in the thermosphere; and that NASA adds four layers of visual noise to obscure our ability to view these organisms--which NASA probably fears are extraterrestrial space craft;...

"Plasmas" up to a kilometer in size and behaving similarly to multicellular organisms have been filmed on 10 separate NASA space shuttle missions, over 200 miles above Earth within the thermosphere. These self-illuminated "plasmas" are attracted to and may "feed on" electromagnetic radiation. They have different morphologies: 1) cone, 2) cloud, 3)...

Plasmas up to a kilometer in size, behaving similarly to multicellular organisms have been filmed on 10 separate NASA space shuttle missions, over 200 miles above Earth within the thermosphere. These self-illuminated "plasmas" are attracted to and may "feed on" electromagnetic radiation. They have different morphologies: 1) cone, 2) cloud, 3) donut...

Astronomy is the oldest science, with connections to development of the most important concepts in physics. A course is described that covers its evolution from prehistory to modern cosmology, giving due weight to the philosophical implications of the subject. The pedagogy is designed to let students develop their writing and reasoning skills. The...

Video is an excellent vehicle for astronomy education and outreach. Usage patterns and user demographics are presented for short videos covering a variety of astronomy topics, delivered to public audiences from three websites, three YouTube channels, and three massive open online classes, or MOOCs. The data spans over a decade in some cases. The mo...

The science of finding habitable planets beyond our solar system and the prospects for establishing human civilization away from our ever-less-habitable planetary home. Planet Earth, it turns out, may not be the best of all possible worlds—and lately humanity has been carelessly depleting resources, decimating species, and degrading everything need...

MOOCs, or massive open online classes have reached hundreds of millions of people around the world in the past decade with a model of free open access learning. They are an excellent vehicle for delivering science to lifelong learners. Building on experience in designing astronomy MOOCs for Udemy and Coursera, we have created an astrobiology MOOC f...

StellarScape is an immersive multimedia performance synthesizing music, science, visual art, and technology. The performance includes live musicians, sensors, electronic music, and dance, collaborating through interactive cinematography. The result combines kinesthetic and acoustic sensing with astrophysical simulations of star formation, in real t...

An overview of the status and prospects of the search for life in the universe is presented. The search for life beyond the Earth is being carried out using a variety of techniques in three distinct realms of space. First is the study of habitable locations in the Solar System using spacecraft and robotic probes. Second is the detection of the glob...

Adults in the United States have a low level of science literacy, and public consensus on major scientific issues like climate change and evolution is hampered by pervasive misinformation and “fake” science on the Internet, often spread by social media. The situation represents a threat to the functioning of civic society. The paper reports on a pr...

We are witnessing a new space race. A half century after the last Moon landing, and after a decade during which the United States could not launch its own astronauts to Earth orbit, there is new energy in the space activity. China has huge ambitions to rival or eclipse America as the major space power, and other countries are developing space progr...

Colonists living on another world will be physically dislocated from the planet of their birth, they will be living in a highly managed, artificial environment, and they will be under huge pressure to make the experiment a success. Lunar colonists will be making a commitment of years or perhaps a lifetime. The only terrestrial situations to rival t...

The search for life beyond the Earth is one of the most compelling quests of modern science. Astrobiology appeals to a wide audience, including those who might not otherwise be engaged with science. This chapter gives an overview of the modes of astrobiology education and outreach that operate in the United States. Astrobiology is one subfield of a...

Future human space missions to Mars and beyond may be realized for different research, economic, political or survival reasons. Since space remains a hazardous environment for humans, space exploration and exploitation requires the development and deployment of effective countermeasures. In this paper, we discuss prospects for human enhancement by...

One side-effect of the COVID-19 pandemic has been increased enrollment in online classes. The paper explores the surge in activity from March through June 2020 in two massive open online classes (MOOCs) on Astronomy, offered by Coursera and Udemy. The increase in enrollment in both classes was an order of magnitude over the similar time span in pre...

The basic science knowledge and attitudes toward science have been compared for (1) adult free-choice learners in an astronomy online course or MOOC, (2) undergraduate non-science majors, and (3) professional scientists from graduate student to professor level. The adult MOOC learners have a higher level of science knowledge than the college studen...

The growth of the Internet has facilitated the easy availability of resources for teaching astronomy, particularly at the introductory level. This overview concentrates on those resources that are free or open access. Basic materials like textbooks, lab activities, and large numbers of astronomical images can be found, along with higher level items...

This book presents a collection of chapters, which address various contexts and challenges of the idea of human enhancement for the purposes of human space missions. The authors discuss pros and cons of mostly biological enhancement of human astronauts operating in hostile space environments, but also ethical and theological aspects are addressed....

As we look beyond our terrestrial boundary to a multi-planetary future for humankind, it becomes paramount to anticipate the challenges of various human factors on the most likely scenario for this future: permanent human settlement of Mars. Even if technical hurdles are circumvented to provide adequate resources for basic physiological and psychol...

The growth of the Internet has facilitated the easy availability of resources for teaching astronomy and doing astronomy outreach. This overview concentrates on resources that are free or open access. Basic teaching materials like textbooks and lab activities can be found, along with higher level items such as concept inventories and interactive in...

In this work we study how different motivations of learners relate to their engagement in a massive open online course (MOOC). The research was conducted in a cohort-based astronomy MOOC “Astronomy: Exploring Time and Space” provided through the Coursera platform. In order to discern motivations of course participants, the Science Motivation Questi...

The discovery and characterisation of planets orbiting distant stars has shed light on the origin of our own Solar System. It is important that college-level introductory astronomy students have a general understanding of the planet formation process before they are able to draw parallels between extrasolar systems and our own Solar System. In this...

Institutions should value teaching and service, and not just research, when considering faculty for promotion and tenure

Mars has occupied a distinctive place in the popular imagination for a century. Science fiction and the wishful thinking of Percival Lowell primed us to think of Mars as a living world, but the first landers and orbiters witnessed a frigid and arid desert landscape. Now the pendulum has swung back toward habitability, with evidence of the red plane...

A manned mission to Mars is faced with challenges and topics that may not be obvious but of great importance and challenging for such a mission. This is the first book that collects contributions from scholars in various fields, from astronomy and medicine, to theology and philosophy, addressing such topics. The discussion goes beyond medical and t...

An increasing amount of formal and informal education is being delivered online. A majority of college students in the U.S. are now taking one or more courses online or flipped (video lectures online, hands-on activities or labs in the classroom). Meanwhile, massive open online classes, or MOOCs, are transforming the landscape of informal science l...

A small survey of the UV-absorbing gas in 12 low-z galaxy groups has been conducted using the Cosmic Origins Spectrograph on board the Hubble Space Telescope. Targets were selected from a large, homogeneously selected sample of groups found in the Sloan Digital Sky Survey. A critical selection criterion excluded sight lines that pass close (<1.5 vi...

A small survey of the UV-absorbing gas in 12 low-$z$ galaxy groups has been conducted using the Cosmic Origins Spectrograph (COS) on-board the Hubble Space Telescope (HST). Targets were selected from a large, homogeneously-selected sample of groups found in the Sloan Digital Sky Survey (SDSS). A critical selection criterion excluded sight lines tha...

The topic of solar system formation has become essential to the teaching of astrobiology due to the discovery of more than 3700 exoplanets, some orbiting within their host star's habitable zone. The architecture of planetary systems is more easily understood when students are able to comprehend how solar systems form. There has yet to be a study th...

[This paper is part of the Focused Collection on Astronomy Education Research.] One goal for a scientifically literate citizenry would be for learners to appreciate when the Earth came to be and where it resides in the Universe. Understanding the Earth’s formation in time in both a sociohistorical and scientific sense allows us to place humanity wi...

[This paper is part of the Focused Collection on Astronomy Education Research.] We report on a study of almost 13 000 undergraduate students enrolled in introductory astronomy courses at the University of Arizona. From 1989 to 2016, students completed a basic science knowledge, beliefs, and attitudes survey. From 2014 to 2016, a subset of the sampl...

Observations with the IRTF and IRAS indicate that there are at least two different mechanisms for the generation of infrared emission from radio galaxies.

In this work we investigate the peer grading assignments which were an integral part of the astronomy Massive Open Online Course (MOOC) (Name of our MOOC) provided through Coursera from March to May 2015. Our general goal is to assess the role of peer graded assignments in such courses and how they contribute to students’ learning and motivation. I...

A web site called Teach Astronomy (http://www.teachastronomy.com) has been created to serve astronomy instructors and their students, amateur astronomers, and members of the general public interested in astronomy. The content includes astronomy articles from an introductory level textbook and from the online resource Wikipedia, short video clips, a...

The COSMOS-Legacy survey is a 4.6 Ms Chandra program that has imaged 2.2 deg$^2$ of the COSMOS field with an effective exposure of $\simeq$160 ks over the central 1.5 deg$^2$ and of $\simeq$80 ks in the remaining area. The survey is the combination of 56 new observations, obtained as an X-ray Visionary Project, with the previous C-COSMOS survey. We...

We present a compilation of UBV RIz light curves of 51 type II supernovae discovered during the course of four different surveys during 1986 to 2003: the Cerro Tololo Supernova Survey, the Calan/Tololo Supernova Program (C&T), the Supernova Optical and Infrared Survey (SOIRS), and the Carnegie Type II Supernova Survey (CATS). The photometry is base...

The prospect of humans living and dying off-Earth raises a set of legal, ethical, and practical questions. After several decades where astronauts have been limited to low Earth orbits, competition between the new and traditional space-faring nations, and aspirations of new players in the commercial space industry, are likely to lead to colonies on...

Astronomy: State of the Art is a massive, open, online class (MOOC) offered through Udemy by an instructional team at the University of Arizona. With nearly 24,000 enrolled as of early 2015, it is the largest astronomy MOOC available. The astronomical numbers enrolled do not translate into a similar level of engagement. The content consists of 14 h...

Of the Drake Equation’s seven factors, fp, the fraction of stars with planets, is the one on which we have made the most progress. Since 1961, we have gone from ignorance to a fairly reliable determination of what this number is. Our progress has occurred in three phases. In the first, which lasted for more than thirty years after 1961, astronomers...

The disciplines of astronomy and statistics are coming together to answer some of the biggest questions in modern science. By Joseph M. Hilbe Impacts from space rocks have set off mass extinctions at least twice in Earth's history. Should we be worried that another strike is imminent? Joseph M. Hilbe and Jamie Riggs assess the risks An overview of...

Limited studies have been performed on the radio-loud fraction in X-ray selected type 1 AGN samples. The consistency between various radio-loudness definitions also needs to be checked. We measure the radio-loudness of the 407 type 1 AGNs in the XMM-COSMOS quasar sample using nine criteria from the literature (six defined in the rest-frame and thre...

Astronomy: State of the Art is a massive, open, online course (MOOC) in astronomy. Course content was released weekly, over 7 weeks, in the spring of 2013. More than 10 hours of video lectures were produced and deployed along with supplementary readings, podcasts, and realtime Q&A sessions with professor Chris Impey. All content is still available...

The California-Arizona Minority Partnership for Astronomy Research and Education (CAMPARE) program represents a new and innovative kind of research program for undergraduates: one that can effectively carry out the goal of recruiting qualified minority and female students to participate in Astronomy and Planetary Science research opportunities, whi...

A new web site called Teach Astronomy (http://www.teachastronomy.com) has been created to serve astronomy instructors and their students, amateur astronomers, and members of the public interested in astronomy. The content includes an online textbook of 400 000 words and 1200 images, 40 000 articles from Wikipedia, over 1100 video clips covering all...

Teach Astronomy—a new, free online resource—can be used as a teaching tool in non-science major introductory college level astronomy courses, and as a reference guide for casual learners and hobbyists. Digital content available on Teach Astronomy includes: a comprehensive introductory astronomy textbook by Chris Impey, Wikipedia astronomy articles,...

The recent "explosion" in the number of extrasolar planets, or exoplanets, is perhaps the most exciting phenomenon in all of science. Two decades ago, no planets were known beyond the Solar System, and now there are more than 770 confirmed exoplanets and several thousand more candidates, while the mass detection limit has marched steadily downwards...

The measurement of galaxy redshifts has changed almost beyond recognition in the past hundred years, progressing from night-long photographic exposures of single targets in the Vesto Slipher era to harvesting tens of thousands of precision CCD redshifts each night. Advances in detector technology and a new generation of 6 to 10 m telescopes have dr...

Personal endings carry the most emotional weight, but our growing awareness of the universe has acquainted us with a spectrum of endings on different cosmic scales. First, there is the occasional intrusion of large pieces of debris from the solar system, which can be triggered by the approach of a nearby star. Then, there is the disruption to life...

Using a physically motivated, model-based active galactic nucleus (AGN) characterization technique, we fit a large sample of X-ray-selected AGNs with known spectroscopic redshifts from the Cosmic Evolution Survey field. We identify accretion disks in the spectral energy distributions of broad- and narrow-line AGNs, and infer the presence or absence...

The California-Arizona Minority Partnership for Astronomy Research and Education (CAMPARE) program represents a new and innovative kind of research program for undergraduates: one that can effectively carry out the goal of recruiting qualified minority and female students to participate in Astronomy and Planetary Science research opportunities, whi...

Science literacy is a matter of broad concern among scientists, educators, and many policy-makers. National Science Foundation surveys of the general public for biannual Science Indicators series show that respondents on average score less than 2/3 correct on a series of science knowledge questions, and less than half display an understanding of th...

Are we alone in the universe? Are the planets our playground to treat as we will, or do we have a responsibility to other creatures who may inhabit or use them? Do we have a right to dump trash in space or leave vehicles on Mars or the moon? How should we interact with other life forms? Encountering Life in the Universe examines the intersection of...

A survey of over 11 000 undergraduate students' knowledge and attitudes related to science and technology over a 22-year period included statements that probed faith-based beliefs and various aspects of pseudoscience belief and superstition. The results reveal that nonscientific ways of thinking are resistant to formal instruction, changing surpris...

Part I. Introduction: Introduction and welcome Cardinal Ljolo; 1. Astrobiology - a new synthesis J. Baross and C. Impey; Part II. Origins of Planets and Life: 2. Towards a theory of life S. Benner and P. Davies; 3. Terran metabolism: the first billion years S. Copley and R. Summons; 4. Planet formation S. Raymond and W. Benz; Part III. History of L...

The mid-infrared-to-ultraviolet (0.1–10 μm) spectral energy distribution (SED) shapes of 407 X-ray-selected radio-quiet type 1 active galactic nuclei (AGN) in the wide-field ‘Cosmic Evolution Survey’ (COSMOS) have been studied for signs of evolution. For a sub-sample of 200 radio-quiet quasars with black hole mass estimates and host galaxy correcti...

We define a quasar-galaxy mixing diagram using the slopes of their spectral energy distributions (SEDs) from 1\mu m to 3000\AA\ and from 1\mu m to 3\mu m in the rest frame. The mixing diagram can easily distinguish among quasar-dominated, galaxy-dominated and reddening-dominated SED shapes. By studying the position of the 413 XMM selected Type 1 AG...

Abstract This paper reports recent efforts to gather experts from the humanities and social sciences along with astrobiologists to consider the cultural, societal, and psychological implications of astrobiology research and exploration. We began by convening a workshop to draft a research roadmap on astrobiology's societal implications and later fo...

This paper is an overview of the diverse ways in which the phenomena of astronomy have penetrated and enriched culture (e.g. the pumpernickel in a loaf of marble rye). Humans have always been able to keep the universe in their heads, but that universe has grown from the proximate, sheltering canopy of stars to a vast panoply of planets, stars, gala...

The "Cosmic Evolution Survey" (COSMOS) enables the study of the Spectral Energy Distributions (SEDs) of Active Galactic Nuclei (AGN) because of the deep coverage and rich sampling of frequencies from X-ray to radio. Here we present a SED catalog of 413 X-ray (\xmm) selected type 1 (emission line FWHM$>2000$ km s$^{-1}$) AGN with Magellan, SDSS or V...

Astronomy workforce development and public engagement in the United States are described. The number of professional astronomers has grown by about a third in the past 25 years, to about 4000. Only one in four are faculty in an academic setting; the rest work in a wide range of public and private research institutes. PhD production has remained ste...

The Center for Astronomy Education's (CAE's) NSF-funded Collaboration of Astronomy Teaching Scholars (CATS) Program is a grassroots multi-institutional effort to increase the capacity for astronomy education research and improve science literacy in the United States.Our primary target population is the 500,000 college students who each year enroll...

We investigate the high-redshift quasar luminosity function (QLF) down to an apparent magnitude of I AB = 25 in the Cosmic Evolution Survey (COSMOS). Careful analysis of the extensive COSMOS photometry and imaging data allows us to identify and remove stellar and low-redshift contaminants, enabling a selection that is nearly complete for type-1 qua...

Bolometric luminosities and Eddington ratios of both X-ray selected broad-line (Type-1) and narrow-line (Type-2) AGN from the XMM-Newton survey in the COSMOS field are presented. The sample is composed by 929 AGN (382 Type-1 AGN and 547 Type-2 AGN) and it covers a wide range of redshifts, X-ray luminosities and absorbing column densities. About 65%...

The Chandra COSMOS Survey (C-COSMOS) is a large, 1.8 Ms, Chandra program that has imaged the central 0.9 deg^2 of the COSMOS field down to limiting depths of 1.9 10^-16 erg cm^-2 s-1 in the 0.5-2 keV band, 7.3 10^-16 erg cm^-2 s^-1 in the 2-10 keV band, and 5.7 10^-16 erg cm^-2 s-1 in the 0.5-10 keV band. In this paper we report the i, K and 3.6mic...

This year we implemented Teach Astronomy (www.teachastronomy.com) as a free online resource to be used as a teaching tool for non-science major astronomy courses and for a general audience interested in the subject. The comprehensive content includes: an introductory astronomy text book by Chris Impey, astronomy articles on Wikipedia, images from t...

Spitzer/IRAC selection is a powerful tool for identifying luminous active galactic nuclei (AGNs). For deep IRAC data, however, the AGN selection wedges currently in use are heavily contaminated by star-forming galaxies, especially at high redshift. Using the large samples of luminous AGNs and high-redshift star-forming galaxies in COSMOS, we redefi...

Spitzer IRAC selection is a powerful tool for identifying luminous AGN. For deep IRAC data, however, the AGN selection wedges currently in use are heavily contaminated by star-forming galaxies, especially at high redshift. Using the large samples of luminous AGN and high-redshift star-forming galaxies in COSMOS, we redefine the AGN selection criter...

We present an AGN selection technique that enables identification of broad-line AGN using only photometric data. An extension of infrared selection techniques, our method involves fitting a given spectral energy distribution with a model consisting of three physically motivated components: infrared power law emission, optical accretion disk emissio...

A survey of the science knowledge and attitudes toward science of nearly 10000 undergraduates at a large public university over a 20-year period included several questions addressing student beliefs in astrology and other forms of pseudoscience. The results from our data reveal that a large majority of students (78%) considered astrology “very” or...

The Cosmological Evolution Survey (COSMOS) is a unique tool for studying low level AGN activity and the co-evolution of galaxies and supermassive black holes. COSMOS involves the largest contiguous region of the sky ever imaged by HST; it includes very complete multiwavelength coverage, and the largest joint samples of galaxy and AGN redshifts in a...

In this paper, we release accurate photometric redshifts for 1692 counterparts to Chandra sources in the central square degree of the Cosmic Evolution Survey (COSMOS) field. The availability of a large training set of spectroscopic redshifts that extends to faint magnitudes enabled photometric redshifts comparable to the highest quality results pre...

We present a rest-frame spectral stacking analysis of ~1000 X-ray sources detected in the XMM-COSMOS field in order to investigate the iron K line properties of active galaxies beyond redshift z~1. In Type I AGN that have a typical X-ray luminosity of Lx~1.5e44 erg/s and z~1.6, the cold Fe K at 6.4 keV is weak (EW~0.05keV), in agreement with the kn...

We present new constraints on the ratio of black hole (BH) mass to total galaxy stellar mass at 0.3 < z < 0.9 for a sample of 32 type-1 active galactic nuclei (AGNs) from the XMM-COSMOS survey covering the range M BH ~ 107.2 – 8.7 M ☉. Virial M BH estimates based on Hβ are available from the COSMOS Magellan/IMACS survey. We use high-resolution Hubb...

The Center for Astronomy Education (CAE) has been devoted to improving teaching & learning in Astro 101 by creating research-validated curriculum & assessment instruments for use in Astro 101 & by providing Astro 101 instructors professional development opportunities to increase their pedagogical content knowledge & instructional skills at implemen...

This poster presents data from a 20-year study into the science literacy of undergraduates enrolled in introductory astronomy courses. Responses from almost 10,000 undergraduate students from 1989 to 2009 have been analyzed. We present students' responses to both science literacy and belief questions by year and demographic variables, as well as tr...

With this paper, we release accurate photometric redshifts for 1692 counterparts to Chandra sources in the central square degree of the COSMOS field. The availability of a large training set of spectroscopic redshifts that extends to faint magnitudes enabled photometric redshifts comparable to the highest quality results presently available for nor...

One day, I'm musing about the vast progress in astronomy in 400 years since Galileo first used the telescope. How would he react to mirrors as large as a small house and telescopes in space and observatories that detect waves billions of times larger and millions of times smaller than the eye can see? In the reverie, Galileo is beside me, in the fl...

Considering the development of life on Earth, the existence of life in extreme environments and the potential for life elsewhere in the Universe, this book gives a fascinating insight into our place in the Universe. Chris Impey leads the reader through the history, from the Copernican revolution to the emergence of the field of astrobiology - the s...

We explore the connection between black hole growth at the center of obscured quasars selected from the XMM-COSMOS survey and the physical properties of their host galaxies. We study a bolometric regime ( 8 x 10^45 erg/s) where several theoretical models invoke major galaxy mergers as the main fueling channel for black hole accretion. We confirm th...

The universe is the largest and most impressive possible arena for the exploration of physical principles. Educational research shows that the act of learning requires active engagement rather than passive transmission of information. Modern astronomy provides several unique advantages for the teaching of physics. It shows a small set of physical l...

We show how accretion rate governs the physical properties of a sample of unobscured broad-line, narrow-line, and lineless active galactic nuclei (AGNs). We avoid the systematic errors plaguing previous studies of AGN accretion rate by using accurate accretion luminosities (L_int) from well-sampled multiwavelength SEDs from the Cosmic Evolution Sur...

We present Subaru/FOCAS spectropolarimetry of two active galaxies in the Cosmic Evolution Survey. These objects were selected to be optically dull, with the bright X-ray emission of an active galactic nucleus (AGN) but missing optical emission lines in our previous spectroscopy. Our new observations show that one target has very weak emission lines...

We show how accretion rate governs the physical properties of broad-line, narrow-line, and lineless active galactic nuclei (AGNs). We avoid the systematic errors plaguing previous studies of AGN accretion rate by using accurate accretion luminosities from well-sampled multiwavelength SEDs from the Cosmic Evolution Survey (COSMOS), and accurate blac...

We have created an online application that clusters the entire Wikipedia and provides a new and useful search engine and interface for the widely used internet knowledge medium. We used an existing open source search engine, and modified it with our own algorithms to give the best possible results from a search query. Astronomy served as the primar...

While fully online citizen science projects like Galaxy Zoo and Moon Zoo are able to garner participation by tens to hundreds of thousands of people, this success pales next to the number of people who use Facebook. With a population well over half a billion, Facebook is, at the time of this writing, the largest single online community. As an exper...

What is the relevance of major mergers and interactions as triggering mechanisms for active galactic nuclei (AGNs) activity? To answer this long-standing question, we analyze 140 XMM-Newton-selected AGN host galaxies and a matched control sample of 1264 inactive galaxies over z ~ 0.3-1.0 and M * < 1011.7 M ☉ with high-resolution Hubble Space Telesc...

We report a sizable class of type 1 active galactic nuclei (AGNs) with unusually weak near-infrared (1-3 μm) emission in the XMM-COSMOS type 1 AGN sample. The fraction of these "hot-dust-poor" AGNs increases with redshift from 6% at low redshift (z < 2) to 20% at moderate high redshift (2 < z < 3.5). There is no clear trend of the fraction with oth...