Conference PaperPDF Available

DAVINCI: Deep atmosphere Venus investigation of noble gases, chemistry, and imaging.

March 2016

Conference: Lunar and Planetary Science Conference
At: Woodlands, TX
Volume: 47

Authors:

James Garvin

NASA

Natasha M Johnson

NASA

David H. Atkinson

California Institute of Technology

Show all 22 authorsHide

No caption available

…

Figures - uploaded by Mikhail Zolotov

Content may be subject to copyright.

Content uploaded by Mikhail Zolotov

Content may be subject to copyright.

DAVINCI: DEEP ATMOSPHERE VENUS INVESTIGATION OF NOBLE GASES, CHEMISTRY, AND

IMAGING. L. S. Glaze1, J. B. Garvin1, N. M. Johnson1, D. Atkinson2,3, S. Atreya4, J. Blacksberg2, W. Brincker-

hoff1, B. Campbell5, D. Crisp2, F. Forget6, M. Gilmore7, D. Grinspoon8, N. Izenberg9, P. R. Mahaffy1, W. Kiefer10,

R. Lorenz9, A. A. Pavlov1, M. Ravine11, M. G. Trainer1, C. Webster2, K. Zahnle12, and M. Zolotov13, 1NASA God-

dard Space Flight Center (Code 690, Greenbelt, MD, 20771, Lori.S.Glaze@nasa.gov), 2Jet Propulsion Laboratory,

3University of Idaho, 4University of Michigan, 5Smithsonian Institution, 6Laboratoire de Météorologie Dynamique,

7Wesleyan University, 8Planetary Science Institute, 9Applied Physics Laboratory, 10Lunar and Planetary Institute,

11Malin Space Science Systems, 12NASA Ames Research Center, 13Arizona State University.

Introduction: Venus formed in the same part of

our solar system, apparently from similar materials, as

Earth. Although both planets are about the same size,

their differences are profound. Venus and Earth expe-

rienced vastly different evolutionary pathways result-

ing in unexplained differences in atmospheric compo-

sition and dynamics, as well as in geophysical process-

es of the planetary surfaces and interiors. Understand-

ing when and why the evolutionary pathways of Venus

and Earth diverged is key to understanding how terres-

trial planets form and how their atmospheres and sur-

faces evolve. The proposed Deep Atmosphere Venus

Investigation of Noble gases, Chemistry, and Imaging

(DAVINCI) mission will provide these missing puzzle

pieces needed to understand terrestrial planet for-

mation and evolution in the solar system and beyond.

Mission Concept: DAVINCI is one of five Dis-

covery-class missions selected by NASA for Phase A

studies. Launching in November 2021 and arriving at

Venus in June of 2023, DAVINCI would be the first

U.S. entry probe to target Venus’ atmosphere in 45

years. DAVINCI is designed to study the chemical and

isotopic composition of Venus’ atmosphere at a level

of detail that has not been possible on earlier missions

and to image the surface at optical wavelengths and

process-relevant scales. The three major DAVINCI

science objectives are:

• Atmospheric origin and evolution: Understand the

origin of the Venus atmosphere, how it has

evolved, and how and why it is different from the

atmospheres of Earth and Mars.

• Atmospheric composition and surface interaction:

Understand the history of water on Venus and the

chemical processes at work in the lower atmos-

phere.

• Surface properties: Provide insights into tectonic,

volcanic, and weathering history of a typical tes-

sera terrain.

The DAVINCI probe will make in situ measure-

ments during a one-hour descent through the Venus

atmosphere. The mission is tightly focused on answer-

ing fundamental questions that have been ranked as

high priority by the last two National Research Council

(NRC) Planetary Decadal Surveys [1-3] as well as by

the Venus Exploration Analysis Group (VEXAG)

since the time of its inception in 2005 [4]. For exam-

ple, DAVINCI will make measurements of the heavi-

est noble gases, including dramatic improvements in

quantifying krypton abundance and the first ever

measurements of xenon, as well as precise isotopic

measurements. These definitive measurements, which

will be made well below the homopause to avoid any

uncertainties, are sufficient to answer questions as

framed by the NRC Planetary Decadal Survey and

VEXAG, without the need to repeat them in New

Frontiers or other future missions. The relative abun-

dances of these inert gases, together with high preci-

sion measurements of the isotopes of argon, nitrogen,

sulfur and carbon provide critical insight into the

origin of Venus’ atmosphere as well as clues regarding

the role of large impacts in its atmospheric evolution.

1560.pdf47th Lunar and Planetary Science Conference (2016)

DAVINCI will make definitive measurements of

hydrogen isotopes that can be used to constrain when

and at what rates Venus lost its putative early water

oceans. DAVINCI will also make the first-ever in situ

trace gas composition measurements within 12 km of

the surface (the altitude at which commercial airlines

cruise on Earth) where 2/3 of the Venus atmospheric

mass resides. These observations will be very useful to

future orbiting missions that need to characterize the

deep atmosphere in order to quantitatively interpret

infrared emissivity observations. The measured com-

position of chemically active gases will provide infor-

mation about chemical processes in the sub-cloud at-

mosphere, the oxidation state of the atmosphere, and

the degree of equilibration among gases in the vicinity

of the surface. This never before obtained information

regarding the composition of the near-surface Venus

atmosphere will lead to new evaluations of stability of

minerals and improved understanding of pathways for

chemical weathering of the surface.

Finally, DAVINCI will return the first-ever high

spatial resolution optical images of the enigmatic high-

land regions known as tessera terrain that may be anal-

ogous to remnant continents. Existing Magellan radar

and topography, combined with Venus Express emis-

sivity results are more than adequate for identifying an

appropriate DAVINCI descent location. The carrier

spacecraft easily receives all data during descent and

relays those data back to Earth without requiring the

presence of additional Venus-orbiting spacecraft.

Payload: DAVINCI builds on the tremendous

success of the Mars Science Laboratory Sample Anal-

ysis at Mars (MSL/SAM) suite carried on the Curiosity

rover [5-12], by pairing the Venus Mass Spectrometer

(VMS) led by NASA’s Goddard Space Flight Center

with the Venus Tunable Laser Spectrometer (VTLS)

led by the Jet Propulsion Laboratory. Combined, these

two instruments provide the first comprehensive meas-

urements of noble and trace gas species, as well as key

elemental isotopes.

These two state-of-the art instruments are comple-

mented by the Venus Atmospheric Structure Investiga-

tion (VASI), which provides measurements of the

structure and dynamics of the Venus atmosphere dur-

ing entry and descent as context for the chemistry

measurements, and enables reconstruction of the de-

scent profile.

High-contrast descent imaging of the tessera terrain

is enabled by the Venus Descent Imager (VenDI), pro-

vided by Malin Space Science Systems based on a

design that leverages experience with the Curiosity

Rover’s Mastcam and MARDI descent video imaging

systems.

References: [1] Crisp, D., et al. (2002) ASP con-

ference Series, 272, Ed. MV Sykes, 5-34. [2] New

Frontiers in the Solar System (2003) National Research

Council of the National Academies, National Acade-

mies Press. [3] Visions and Voyages (2011) National

Research Council of the National Academies, National

Academies Press. [4] VEXAG (2014)

http://www.lpi.usra.edu/vexag/reports/GOI-

140625.pdf. [5] Mahaffy et al. (2015) Science, 347,

412-414. [6] Webster et al. (2015) Science, 347, 415-

417. [7] Atreya et al. (2013) GRL, 40, 5605-5609. [8]

Mahaffy et al. (2013) Science, 341, 263-266. [9] Web-

ster et al. (2013) Science, 341, 260-263. [10] Wong et

al. (2013) GRL, 40, 6033-6037. [11] Conrad et al.

(2014) LPSC XLV, Abstract #2366. [12] Trainer et al.

(2016) LPSC XLVII Abstract.

1560.pdf47th Lunar and Planetary Science Conference (2016)

A Framework for Utilization of DAVINCI+ Measurements to Study Physical State of Venus Near Surface Environment

Poster

Dec 2020

The atmosphere of Venus has been explored by many probes and lander missions, which investigated different regions of the atmosphere, including chemical composition, dynamics and thermal structure. However, the repeatability and accuracy of measurements of the near-surface environments provided by the missions of previous decades is lacking, and there is a need for more accurate and precise measurements to study the near surface environment and its physical state. Vega 2 measurements are regarded as the most reliable temperature measurements for the deep atmosphere with an error bar of 0.5 K. Recent analyses of Vega 2 measurements indicate presence of a supercritical fluid state in the last few kilometers above the Venus surface, an increasing concentration of nitrogen with altitude. The DAVINCI+ deep atmosphere chemistry probe, now in Phase A led by Principal Investigator Dr. James B. Garvin and NASA GSFC will study the atmospheric structure and chemical composition of Venus’ lower atmosphere. The Venus Atmospheric Structure Investigation (VASI) payload will provide temperature and pressure measurements during the entry and descent stages, while the Venus Mass Spectrometer (VMS) payload will provide measurements for nitrogen isotope abundances. We will present a framework for the deep atmosphere chemistry probe measurements to study the physical state and thermodynamic properties of the deep atmosphere of Venus based on the knowledge and principles of thermodynamic properties of states and previous atmosphere probes. The goal of the framework is to investigate the supercritical state of Venus atmosphere, check the possibility of existence of a concentration gradient, and to take advantage of proposed DAVINCI+ probe synergistic measurements.

Spin-scanning Cameras for Planetary Exploration: Imager Analysis and Simulation

Thesis

Full-text available

Nov 2021

George Brydon

In this thesis, a novel approach to spaceborne imaging is investigated, building upon the scan imaging technique in which camera motion is used to construct an image. This thesis investigates its use with wide-angle (≥90° field of view) optics mounted on spin stabilised probes for large-coverage imaging of planetary environments, and focusses on two instruments. Firstly, a descent camera concept for a planetary penetrator. The imaging geometry of the instrument is analysed. Image resolution is highest at the penetrator’s nadir and lowest at the horizon, whilst any point on the surface is imaged with highest possible resolution when the camera’s altitude is equal to that point’s radius from nadir. Image simulation is used to demonstrate the camera’s images and investigate analysis techniques. A study of stereophotogrammetric measurement of surface topography using pairs of descent images is conducted. Measurement accuracies and optimum stereo geometries are presented. Secondly, the thesis investigates the EnVisS (Entire Visible Sky) instrument, under development for the Comet Interceptor mission. The camera’s imaging geometry, coverage and exposure times are calculated, and used to model the expected signal and noise in EnVisS observations. It is found that the camera’s images will suffer from low signal, and four methods for mitigating this – binning, coaddition, time-delay integration and repeat sampling – are investigated and described. Use of these methods will be essential if images of sufficient signal are to be acquired, particularly for conducting polarimetry, the performance of which is modelled using Monte Carlo simulation. Methods of simulating planetary cameras’ images are developed to facilitate the study of both cameras. These methods enable the accurate simulation of planetary surfaces and cometary atmospheres, are based on Python libraries commonly used in planetary science, and are intended to be readily modified and expanded for facilitating the study of a variety of planetary cameras.

Study of minor species in the Venus night mesosphere

Thesis

Jan 2021

Daria Evdokimova

Chemical processes of the dense CO2-atmosphere of Venus are determined by trace gases such as SO2, O3, H2O, CO, etc. Among these atmospheric components, a group of sulfur and oxygen compounds occupies a central position. The objective of this thesis is a study of sulfur dioxide and ozone at the night side of Venus' upper mesosphere that is related to altitudes from 85 to 110 km. Chemistry and dynamics of this altitude range is very active. The sulfuric chemical cycle in the mesosphere leads to a formation of the thick cloud deck at 47-70 km globally enshrouding the planet. Furthermore, it has not yet been determined exactly which chemical interactions are responsible for stabilizing the equilibrium in the chemical cycles of the atmosphere, and maintaining a high mixing ratio of CO2. The difficulty of evaluating the oxidizing capacity of the atmosphere, due to the lack of direct measurements of the amount of molecular oxygen, is one reason for this. However, indirect O2 estimations can be made based on derivatives of this molecule, and one of them is ozone. This gas is involved in reactions with species, probably mainly chlorinated compounds, leading to the general chemical cycles.The research is based on the data obtained from the first stellar occultation experiment released for Venus. It was performed by the UV channel of the SPICAV spectrometer onboard Venus Express orbiter working in 2006-2014. This is a powerful instrument to measure absorption of CO2, SO2 and O3 at the night side of Venus’ atmosphere above the cloud layer. This study also includes a detailed assessment of the accuracy of the spectral data processing methods used to retrieve vertical atmospheric gas concentration distributions. Mainly it concerns a separation of a stellar light from UV emission signal originated from different spread sources, which is a parasitic light for the stellar occultation data investigation. A significant influence of a calibration assignment of wavelength to a digital pixel number was obtained. The required accuracy was achieved by a determination of stellar lines position for a large set of stars' spectra measuring in each observational session. Thus, it allowed to establish a profile of the SO2 content from 85 km to 100 km mainly devoted to mid-latitudinal range. On average, it shows a stable mixing ratio with altitude. For this gas, a prevailed short-period variability has been confirmed. However, a weak possible increase of SO2 abundance with local time is noticed from the morning to the evening terminator at 90-95 km. After the discovery of the ozone layer on Venus made by Montmessin et al. (2011), the ozone content was confirmed in more than 100 occultation sessions. The current study also shows that the detected ozone values correspond to its maximum values rather than to the thick stable layer. These results are the first detailed vertical distribution of the SO2 and O3 content in the upper mesosphere on the night side, which opens up new possibilities for the theoretical description of processes occurring in the atmosphere of Venus.

VERITAS (Venus Emissivity, Radio Science, InSAR, Topography, and Spectroscopy): A Discovery Mission

Conference Paper

Mar 2022

Deep understanding of planetary habitability requires identifying key factors that govern the surface environment over time. Venus is the ultimate control case for understanding how Earth developed and maintained conditions suited to life. Venus very likely had elements essential to habitability such as past surface water and a dynamo. Tectonism and volcanism, which create chemical disequilibrium, very likely persist today. What caused Earth and Venus to diverge down different evolutionary paths? VERITAS would create foundational, co-registered data sets of high-resolution topography, imaging, spectroscopy, and gravity, on par with those available for Mercury, Mars, and the Moon. VERITAS would answer outstanding fundamental questions about the evolution of Earth's twin. The VERITAS payload consists of the Venus Interferometric Synthetic Aperture Radar (VISAR) and the Venus Emissivity Mapper (VEM), plus a gravity science investigation. VISAR is an X-band radar that provides: 1) a global digital elevation model (DEM) with 250-m postings and 6-m height accuracy, 2) Synthetic aperture radar (SAR) imaging at 30-m horizontal resolution globally, 3) SAR imaging at 15-m resolution for $> \boldsymbol{25\%}$ of the surface, and 4) surface deformation from repeat pass interferometry (RPI) with 2-cm vertical precision for $> \boldsymbol{12} \boldsymbol{(\sim 200\ \mathrm{x}\ 200\ \text{km})}$ targeted areas. VEM covers $\boldsymbol{ > 70\%}$ of the surface in six near-infrared (NIR) bands sensitive to iron composition located within five atmospheric windows, plus eight atmospheric bands for calibration and water vapor measurements. VEM would provide near-global maps of mafic to felsic rock type and will search for active and recent volcanism. VERITAS would use two-way Ka-band uplink and downlink from a low circular orbit $\boldsymbol{(< 250\ \text{km})}$ to create a global gravity field with 3-mGal accuracy of 155-km resolution (degree and order 123). An onboard technology demonstration, the Deep Space Atomic Clock (DSAC-2), may support radio science and navigation with one-way tracking. VERITAS data would enable estimation of elastic thickness (a proxy for thermal gradient) and density differences due to subsurface structures, as well as constraining interior structure, including core size and state. Lockheed Martin builds the spacecraft. VISAR is built by JPL, with the Italian Space Agency (ASI) providing the low power electronics. ASI also provides transponders and a high gain antenna for the telecom system. CNES provides the Ka-band traveling wave tube amplifiers (TWTA). The German Space Agency (DLR) provides VEM and contributes algorithms for VISAR ground and onboard data processing.

The Deep Atmosphere Venus Investigation of Noble gases, Chemistry and Imaging (DAVINCI) Mission: Flight System Design Technical Overview

Conference Paper

Mar 2022

It's Time for Focused In Situ Studies of Planetary Surface-Atmosphere Interactions

Conference Paper

Mar 2022

Crater Ejecta Across Maxwell Montes, Venus, and Possible Effects on Future Rock Type Measurements

Article

Full-text available

May 2022
GEOPHYS RES LETT

Venus highlands such as Maxwell Montes are an exploration target in the search for a past water‐rich environment. We combine Magellan and Arecibo radar data to characterize surface properties across Maxwell for orbital or landed investigations. Arecibo data reveal a region surrounding and west of the 90‐km crater Cleopatra with lower radar echoes and circular polarization ratio despite increased surface reflectivity. Modeling of microwave emissivity shows that the surface undergoes step‐like reflectivity shifts at ∼6056.2 km and ∼6,061 km radius, such that the changes in radar echo between these altitudes are not due solely to dielectric effects. We propose that fine‐grained Cleopatra ejecta mantles much of Maxwell Montes, consistent with Venus distal crater ejecta patterns and the longevity of mantling debris in the highlands. Future orbital or landed studies must consider the thickness of ejecta, source material, and effects of shock or melting on ejecta mineralogy.

Estimates on the Frequency of Volcanic Eruptions on Venus

Article

Full-text available

Jan 2022

Venus hosts many thousands of volcanic landforms, including individual edifices, volcanotectonic structures, and vast expanses of effusively emplaced plains lavas. Numerous lines of circumstantial evidence together suggest that the planet is volcanically active today. Although previous studies have calculated volcanic eruptive fluxes on the basis of the volumes of lava needed to bury craters of various diameters on Venus, no estimates of the frequency of volcanic eruptions on the planet yet exist. In this study, we analyzed records for eruptive events on Earth between 1 January 1980 and 21 January 2021 for which data on duration and eruption intensity were available, and classified those events by tectonic setting. We then extrapolated those results to Venus by a simple scaling factor. We estimate that as many as 120 discrete eruptions, from individual volcanic edifices and of any duration and intensity, may occur on Venus per Earth year. Further, within any given 60‐day window—a nominal timeframe over which an aerial platform capable of detecting volcanic activity might operate in the middle Venus atmosphere—we expect about four new eruptions to begin, with that number rising to almost eight when both new events and those ending within 100 days of the main eruption are included, or to as many as 20 when considering activity that lasts for 1,000 days. Several complementary techniques exist with which to search for volcanic eruptions at Venus, either from orbit, within the atmosphere, or on the surface, that can be used to test the estimates we make here.

The Geologically Supervised Spectral Investigation as a Key Methodology for Identifying Volcanically Active Areas on Venus

Article

Full-text available

Jul 2021

Combining geologic mapping and stratigraphic reconstruction of lava flows at Sapas, Maat and Ozza Montes, three potentially young volcanic structures of Atla Regio on Venus, with analysis of the spectral signature (radar emissivity anomalies) characterizing each mapped flow, Brossier et al. (2021), https://doi.org/10.1029/2020je006722 conclude that some of the lava flows at Maat Mons may be geologically recent (∼25 Ma). The lava flows of Sapas and Ozza Montes are more consistent with weathered lava flows forming chlorapatite and some perovskite oxides. We discuss the reasons why, besides the importance of the results they obtained, the methodology they used can be very valuable for future investigations with higher resolution datasets.

Lava Worlds: From Early Earth to Exoplanets

Article

Jan 2021
CHEM ERDE-GEOCHEM

The magma ocean concept was first conceived to explain the geology of the Moon, but hemispherical or global oceans of silicate melt could be a widespread lava world” phase of rocky planet accretion, and could persist on planets on short-period orbits around other stars. The formation and crystallization of magma oceans could be a defining stage in the assembly of a core, origin of a crust, initiation of tectonics, and formation of an atmosphere. The last decade has seen significant advances in our understanding of this phenomenon through analysis of terrestrial and extraterrestrial samples, planetary missions, and astronomical observations of exoplanets. This review describes the energetic basis of magma oceans and lava worlds and the lava lake analogs available for study on Earth and Io. It provides an overview of evidence for magma oceans throughout the Solar System and considers the factors that control the rocks these magma oceans leave behind. It describes research on theoretical and observed exoplanets that could host extant magma oceans and summarizes efforts to detect and characterize them. It reviews modeling of the evolution of magma oceans as a result of crystallization and evaporation, the interaction with the underlying solid mantle, and the effects of planetary rotation. The review also considers theoretical investigations on the formation of an atmosphere in concert with the magma ocean and in response to irradiation from the host star, and possible end-states. Finally, it describes needs and gaps in our knowledge and points to future opportunities with new planetary missions and space telescopes to identify and better characterize lava worlds around nearby stars.

ResearchGate has not been able to resolve any references for this publication.

DAVINCI: Deep atmosphere Venus investigation of noble gases, chemistry, and imaging.

Figures

Recommendations

Overview of the SPICAV/SOIR results in the context of dynamics and chemistry of the Venus atmosphere

VULCAN: A Concept Study for a New Frontiers-Class Venus Lander

Weathering of Hawaiian Basalts Under Sulfur-Rich Conditions: Applications to Understanding Surface-A...

Remote Raman-Laser Induced Breakdown Spectroscopy (LIBS) Geochemical Investigation Under Venus Atmos...