J
John H. Hoffman
Researcher at University of Texas at Dallas
Publications - 33
Citations - 2967
John H. Hoffman is an academic researcher from University of Texas at Dallas. The author has contributed to research in topics: Atmosphere & Mars Exploration Program. The author has an hindex of 14, co-authored 33 publications receiving 2700 citations. Previous affiliations of John H. Hoffman include Texas Christian University.
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Journal ArticleDOI
Detection of Perchlorate and the Soluble Chemistry of Martian Soil at the Phoenix Lander Site
Michael H. Hecht,Samuel P. Kounaves,Richard C. Quinn,S. J. West,S. M. M. Young,Douglas W. Ming,David C. Catling,David C. Catling,B. C. Clark,William V. Boynton,John H. Hoffman,Lauren DeFlores,K. Gospodinova,J. Kapit,Peter H. Smith +14 more
TL;DR: Results suggest that the soil at the Phoenix landing site must have suffered alteration through the action of liquid water in geologically the recent past, and revealed an alkaline environment in contrast to that found by the Mars Exploration Rovers, indicating that many different environments have existed on Mars.
Journal ArticleDOI
H2O at the Phoenix landing site.
Peter H. Smith,L. K. Tamppari,Raymond E. Arvidson,D. S. Bass,Diana L. Blaney,William V. Boynton,Allan I. Carswell,David C. Catling,David C. Catling,B. C. Clark,Thomas J. Duck,E. DeJong,David A. Fisher,Walter Goetz,Haraldur P. Gunnlaugsson,Michael H. Hecht,V. Hipkin,John H. Hoffman,Stubbe F. Hviid,H. U. Keller,Samuel P. Kounaves,Carlos F. Lange,Mark T. Lemmon,Morten Madsen,W. J. Markiewicz,John Marshall,Christopher P. McKay,Michael T. Mellon,D. W. Ming,R. V. Morris,William T. Pike,Nilton O. Renno,Urs Staufer,Carol R. Stoker,Peter A. Taylor,James A. Whiteway,Aaron P. Zent +36 more
TL;DR: The analysis of the data from the Phoenix mission revealed an alkaline environment, in contrast to that found by the Mars Exploration Rovers, indicating that many different environments have existed on Mars.
Journal ArticleDOI
Venus Was Wet: A Measurement of the Ratio of Deuterium to Hydrogen
TL;DR: The deuterium-hydrogen abundance ratio in the Venus atmosphere was measured while the inlets to the Pioneer Venus large probe mass spectrometer were coated with sulfuric acid from Venus' clouds.
Journal ArticleDOI
Evidence for Calcium Carbonate at the Mars Phoenix Landing Site
William V. Boynton,D. W. Ming,Samuel P. Kounaves,S. M. M. Young,Raymond E. Arvidson,Michael H. Hecht,John H. Hoffman,Paul B. Niles,D. K. Hamara,Richard C. Quinn,Peter H. Smith,Brad Sutter,David C. Catling,David C. Catling,R. V. Morris +14 more
TL;DR: Results suggest that the soil at the Phoenix landing site must have suffered alteration through the action of liquid water in geologically the recent past, and an alkaline environment was revealed, in contrast to that found by the Mars Exploration Rovers, indicating that many different environments have existed on Mars.
Journal ArticleDOI
Composition of the Venus lower atmosphere from the Pioneer Venus Mass Spectrometer
TL;DR: The data from the Pioneer Venus sounder probe neutral mass spectrometer confirm that the major constituents of the lower atmosphere of Venus are CO2 and N2, with the latter having a mass abundance of about 3% The data allow the order of up to 1000 ppm of water vapor and 500 ppm of SO2 and COS below the clouds as mentioned in this paper.