What Is A Framing Camera

Exploration and Assay of Planetary Shape and Topography Using Stereophotogrammetry

Jürgen Oberst , ... Frank Preusker , in Encyclopedia of the Solar Organisation (Tertiary Edition), 2014

2.1 Framing Cameras

Framing cameras are equipped with frame Charge-Coupled Device (CCD) or Active Pixel Sensor (APS) array sensors or even (in the early mapping of the World and Moon) photographic picture. Hither, mathematically unproblematic geometric conversions exist that relate positions of a feature on the sensor surface to viewing vectors for each sensor pixel. The image geometry is very stable, i.e. the relative positions of the pixels are precisely known. Stereo images are caused by pointing the camera from different body-fixed positions to the surface feature of interest. Alternatively, for pocket-size objects as asteroids, the photographic camera may remain at some inertially fixed position, while the asteroid rotates beneath the photographic camera position.

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Planets, Asteriods, Comets and The Solar Organisation

T.H. Burbine , in Treatise on Geochemistry (Second Edition), 2014

2.fourteen.v.7 Dawn

The Dawn spacecraft orbited Vesta from July 2011 until September 2012 and is scheduled to reach Ceres in Feb 2015 (Russell et al., 2004, 2007 ). Dawn has a framing camera (with one articulate filter and seven narrow band filters), visible and near-infrared spectrometer with a full coverage of 0.25 and five.0 μm, and a gamma-ray/neutron detector. Gamma rays emitted by Vesta include those from naturally decaying radioactive elements (e.g., thorium, uranium, and potassium) and excited nuclei (east.thou., atomic number 26, magnesium, silicon, aluminum, titanium, oxygen, and calcium; Prettyman, 2007). The energies of neutrons emitted from the surface due to incoming galactic cosmic rays and solar particles are sensitive to light elements such as hydrogen, carbon, and nitrogen and neutron absorbers such equally gadolinium and samarium.

Images of Vesta (Jaumann et al., 2012; Marchi et al., 2012; Schenk et al., 2012) prove a heavily cratered northern hemisphere and a large bear on basin (Rheasilvia) at the s pole ( Figure 34 ). A crater at the s pole of Vesta was previously identified by Hubble Infinite Telescope images of Vesta (Thomas et al., 1997). Vesta besides has a large number of equatorial troughs (Buczkowski et al., 2012), which have characteristics consistent with graben (a depressed part of the crust bounded by faults). The visual geometric albedo of Vesta varies from 0.10 to 0.67 (Reddy et al., 2012a), which is the largest variation observed on an asteroid.

Equally expected, visible and near-infrared spectra of Vesta taken past Dawn (De Sanctis et al., 2012a; Reddy et al., 2012a) are consistent with HED meteorites and footing-based observations. Gamma ray-derived Iron/O and Iron/Si elemental ratios of Vesta'due south surface (Prettyman et al., 2012), which are measurements that cannot exist done from Earth, are likewise consistent with HED meteorites. Dawn as well has found evidence for hydrated minerals on the surface of Vesta from the detection of widespread hydrogen on the surface from neutron measurements (Prettyman et al., 2012), detection of a widespread 2.viii μm feature (De Sanctis et al., 2012b), and the spectral similarity of Vesta'due south dark fabric to carbonaceous chondrites (McCord et al., 2012; Reddy et al., 2012b). These Dawn results are consistent with the Hasegawa et al. (2003) observation of a iii μm band for Vesta and the identification of carbonaceous chondrite clasts in HEDs (e.g., Buchanan et al., 1993). A spectral study of Vesta using Dawn data by Pieters et al. (2012) plant no show for the accumulation of lunar-like nanophase fe on the surface due to the absence of most-infrared spectral gradient differences between freshly exposed and background regolith material. This lack of space weathering on Vesta'south surface could be due a magnetic field (Vernazza et al., 2006b; Fu et al., 2012) and/or compositional differences between Vesta and other space-weathered bodies (due east.one thousand., Moon, Itokawa).

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Comparison Sample and Remote-Sensing Information—Agreement Surface Composition

Jennifer A. Grier , Andrew S. Rivkin , in Airless Bodies of the Inner Solar Arrangement, 2019

Morphological Imaging

Photogeology is a long-standing, well-established technique for agreement surfaces. A full discussion of photogeology is well across the scope of this book, but nosotros notation that these techniques are normally applied to the airless bodies for the identification of landforms similar craters, ridges, lava flows, landslides, etc.

Information for morphological studies are generally taken with cameras very much like the ones in mutual use past the public. In that location are two types of photographic camera modes: framing and TDI ("time delay and integration," commonly chosen "pushbroom"). Framing cameras take an exposure of a fixed length, with the entire image obtained simultaneously. This is the aforementioned way that everyday cameras we use operate. Pushbroom imagers are more like the panorama mode in mobile phones, with the prototype built upward line past line over fourth dimension. While mobile phone panoramas typically require movement of the photographic camera, spacecraft pushbroom imagers ofttimes stare in a stock-still direction and build up images from the spacecraft orbital motility around the target. Pushbroom imagers are ofttimes imaging spectrometers, returning a full spectrum for each line of spatial coverage resulting in a 3-D image cube with two spatial and 1 spectral dimension.

Cameras can have very loftier spatial resolution. The narrow-angle camera (NAC) on LRO returns images at 50 cm/pixel, so a full image will only cover ~ ane km². The surface area of the Moon is nigh 38 million square kilometers, and then a given NAC frame may non be like shooting fish in a barrel to find on a full map of the Moon. As a result, the LRO NAC is paired with a wide-angle camera (WAC) pointed at the same location every bit the NAC and providing 100 thousand/pixel imaging to provide context for the NAC images. This arrangement of a NAC + WAC imaging system is common on planetary missions to larger objects similar Mercury. Other objects similar Eros and Itokawa are sufficiently pocket-size that even very high spatial resolution images capture a significant fraction of their surfaces: a x-cm pixel scale for an imaging array of 2000 × 2000 pixels would capture well over one-half of Itokawa in a single image. Because relatively few WAC images are needed to cover an object compared to the number of NAC images, WAC instruments are commonly synthetic with color filters and the ability to accept spectrophotometric data. Conversely, the high spatial resolution of NACs typically requires them to be taking data at a very high rate while still typically imaging only a relatively small fraction of a target surface.

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A Brief History of Spacecraft Missions to Asteroids and Protoplanets

Beth E. Clark , ... Hal Levison , in Primitive Meteorites and Asteroids, 2018

1.15 Dawn: 1 Ceres

After spending about 14 months at 4 Vesta in 2011–12, Dawn arrived at 1 Ceres in March 2015 and used its ion engines to maneuver to mapping orbits (Fig. ane.26) optimized for visible and infrared hyperspectral mapping, color and multiangle imaging, and gamma ray/neutron spectroscopy and radio science (Russell and Raymond, 2011). Dawn's instruments are illustrated in the section on 4 Vesta—meet Fig. one.21.

Dawn observed one Ceres, classified every bit a C-blazon body, during a xvi-calendar month primary mission and completed a 12-month extended mission in June 2017. The nighttime surface of Ceres (average albedo = 0.09) is heavily cratered and punctuated by bright areas, called faculae (run into Fig. 1.27). Dawn mapped Ceres' surface globally to ∼35 m/pixel with the FC panchromatic filter, revealing an unexpectedly, rough surface for its presumed icy limerick. The surface includes heavily cratered terrain in the northward and smoother areas in several midlatitude regions. Domes are prevalent in several regions, and fractures of all sizes dominate the landscape. Dawn determined 1 Ceres to be triaxial with dimensions 966.2 × 962.0 × 891.8 km in bore, with a mean radius of 470 km (Park et al., 2016). Topography ranges from −seven.3 to +nine.5 km on a best-fit biaxial ellipsoid of 482 × 446 km. There is a large highland named Hanami planum that hosts the Occator crater that hosts the brightest fabric seen on the surface, as well as several deep planitia; craters larger than ∼300 km radius are not observed.

The average surface limerick of ane Ceres measured by VIR is dominated past ammoniated Mg-rich phyllosilicates, the phyllosilicate serpentine, Mg–Ca-rich carbonate, and a dark component (De Sanctis et al., 2015). No evidence of olivine or pyroxene has been establish. The surface limerick is remarkably uniform (Ammannito et al., 2016); but the brightest areas (faculae) in several craters have a limerick rich in Na-carbonate with ammonium carbonates or chlorides (De Sanctis et al., 2016 ). These faculae are frequently found within craters whose ejecta display a blue visible slope (observed past the Dawn Framing Camera), indicating their relative youth ( Stephan et al., 2017). The ammoniated clays found all over i Ceres' surface indicate extensive water–stone interaction. The ubiquitous presence of ammoniated clays on Ceres' surface indicates a global episode of alteration, requiring extensive water mobility, presumed to be a global subsurface body of water (Ammannito et al., 2016). The presence of ammonia may point that Ceres itself, or the material from which ane Ceres formed, migrated from the colder environment of the outer solar system and scattered inward toward its current position in the main asteroid belt past behemothic planet migration (Raymond and Izodoro, 2017).

Equally revealed by nuclear spectroscopy data from the GRaND instrument and also seen by VIR, the elemental composition of 1 Ceres indicates widespread water water ice and products of aqueous alteration are delivered to the surface from ane Ceres' interior (Prettyman et al., 2017). An ice tabular array resides at shallow depth in polar regions, receding to a few meters depth at the equator. The elemental composition of Ceres' water ice-free regolith in the equatorial region is similar to CI and CM meteorites, which are considered analogs for Ceres (McSween et al., 2017). However, primitive meteorites likely experienced isochemical aqueous amending on smaller parent bodies, whereas 1 Ceres appears to be moderately chemically fractionated (Castillo-Rogez and Young, 2017). As bear witness of this difference, the iron affluence in 1 Ceres' regolith is lower than the average value for CI and CM chondrites, which is consistent with sinking of metal-rich particles in a global ocean (Prettyman et al., 2017).

Shape and gravity data indicate a partially differentiated interior with a potent xl-km thick chaff of low density (∼one.250 g/cm³), overlying a weaker hydrated silicate interior of density close to CI chondrites (∼2.450 g/cm³), as illustrated in Fig. i.28 (Park et al., 2016; Fu et al., 2017; Ermakov et al., 2017). A strong lithified deep interior below 100 km cannot exist excluded by the data. The degree of chemical fractionation points to an early formation time for 1 Ceres, within a few one thousand thousand years of CAIs (Castillo-Rogez et al., 2017), when the live Al²⁶ needed for radiogenic heating persisted in the accretionary surround. However, fractional physical differentiation points to the role of hydrothermal circulation in an early forming subsurface ocean in moderating internal heating (Fu et al., 2017; Travis 2017). Evidence for a relict bounding main at present might be constitute in the weak hydrated silicate layer inferred by Fu et al. (2017).

The surface of one Ceres presents compelling evidence of contempo brine-driven geologic activity. The steep-sided Ahuna Mons, the largest mountain on 1 Ceres, has been interpreted to be a cryovolcano, constructed when material, in which viscosity was decreased past the presence of a few pct of briny fluid, erupted onto the surface (Ruesch et al., 2016; come across Fig. one.29). Ahuna Mons displays bright streaks of sodium carbonate–rich composition on its flanks (Zambon et al., 2016), besides consistent with sourcing from a brine reservoir. Cryovolcanism, possibly induced by impacts, may as well contribute to flows and brilliant deposits in young impact craters such every bit Occator (Nathues et al., 2017; run across Fig. 1.xxx). Other bright deposits that are seen across the surface of Ceres (Stein et al., 2017) appear to be excavated from 1 Ceres' crust, suggesting they contain a pregnant fraction of material of oceanic origin.

As if one Ceres was not interesting enough, aliphatic organic material was found in a localized deposit in and effectually a northern-hemisphere crater called Ernutet (Fig. 1.31) (De Sanctis et al., 2017), which as well displays a unique cherry color. Several smaller more than dilute deposits of organic fabric have as well been found. The endogenic versus exogenic origin of these materials remains a mystery at this time (Pieters et al., 2017); however, an endogenic hypothesis is favored.

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Comparative studies of meteoroid-planet interaction in the inner solar system

Apostolos A. Christou , ... Helmut O. Rucker , in Planetary and Space Science, 2007

Depiction of the interaction of a meteoroid with the different layers of an temper. Apart from the emission of electromagnetic energy in the form of low-cal and very-low-frequency radiations, the ablation procedure deposits electrons and metallic ions in the ionosphere.

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FC colour images of dwarf planet Ceres reveal a complicated geological history

A. Nathues , ... C.T. Russell , in Planetary and Space Scientific discipline, 2016

1 Introduction

The Dawn spacecraft (Russell and Raymond, 2012 ) carries ii Framing Cameras (FCs) which obtained images in seven colours (centre wavelength at 0.43, 0.55, 0.65, 0.75, 0.83, 0.92 and 0.98µm) and i clear filter ranging between 0.45 and 0.92µm ( Sierks et al., 2012), mapping the surface of Ceres at ~140m/pixel during the High Altitude Mapping Orbit (HAMO), i.e., from ~1400km above the surface (Russell et al., 2016). Prototype mosaics, derived via applying prototype processing tools (Nathues et al., 2015; Reddy et al., 2012), are used to determine the global surface colour characteristics of Ceres. All colour mosaics, forming a global prototype cube, take been photometrically corrected by applying Hapke's photometric model (Hapke, 1981, 1999, 2012 and references therein) using iteratively derived light scattering parameters from Approach, Survey orbit and HAMO orbit imagery. Potential endogenic resurfacing processes such every bit cryovolcanism (e.g., Castillo-Rogez et al., 2011; Ruesch et al., 2016) as well as impact-induced tectonics (Hiesinger et al., 2016) have mainly shaped the cerean surface, forming a few large basins and a multitude of craters, of which some have been modified by viscous relaxation as indicated by crater morphology (see Fig. oneA). Surface areas retaining original primordial composition several one thousand thousand years after accretion and partial differentiation (e.g., Mc Cord and Sotin, 2005; Castillo-Rogez and Mc String, 2010) may not exist anymore due to resurfacing, or they are at to the lowest degree challenging to identify. The most pristine materials tin probably exist found at locations of the well-nigh recent, unweathered surfaces: fresh crater ejecta and exposed crater interior materials. Nosotros are going to show apparent correlations of the local geologic history with color properties. One expanse where craters >5km are absent, i.east., the surface is less modified by larger impacts only of older age, has been selected as our spectral standard site (Fig. S3D).

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Asteroid (iv) Vesta II: Exploring a geologically and geochemically circuitous world with the Dawn Mission

Timothy J. McCoy , ... David W. Mittlefehldt , in Geochemistry, 2015

4.2 Craters, mountains and troughs

The being of a southward polar basin on Vesta created tremendous anticipation for the first images of the asteroid. While still 189,000 km away, Dawn'due south framing camera captured images with better than twice the resolution of those taken by the Hubble Space Telescope (HST) in 1997 ( http://dawn.jpl.nasa.gov/feature_stories/dawn_vesta_062011_full_description.asp). By early July 2011, at distances in excess of 40,000 km from Vesta, Dawn'due south framing camera began to provide detailed images that would redefine our understanding of the surface of the largest asteroid visited to date.

The most dramatic feature revealed in the earliest images was the central uplift of the south pole bowl Rheasilvia (Fig. 6) (Schenk et al., 2012). Created by rebound of the underlying rock after peak compression during crater formation, primal uplifts are a common feature of big affect basins on the Earth, Moon, Mars and Mercury, every bit well as on the satellites of the outer planets. As noted past Schenk et al. (2012), the dimensions of Rheasilvia are similar to that observed on the midsize icy satellites Hyperion, Rhea, and Iapetus. These authors suggested that the basic morphology of a large cardinal uplift dominating over rim plummet and multi-ring basin formation may be characteristic of depression-gravity bodies. During the survey orbit at ∼2700 km altitude, stereophotogrammetric analysis revealed an overall relief from −22.iii to 19.one km, which slightly exceeds the relief indicated past HST images (−25.4 to 13.7 km). As expected, a large area of low relief was observed virtually the southward pole of Vesta. When recast to a project centered on the south pole (Fig. 7), the calibration and relief of the Rheasilvia basin become obvious.

At ∼500 km in diameter and ∼19 km deep (Schenk et al., 2012), Rheasilvia is among the largest basins relative to the diameter of the planetary body in the Solar System. With nearly 20 km of vertical relief, the central uplift in the Rheasilvia bowl stands equally the second highest mountain in the Solar System, significantly exceeding the Hawaiian shield volcanoes and trailing just the massive Olympus Mons shield volcano on Mars. It is remarkable that the Rheasilvia fundamental top formed non through convergent plate tectonics or hot-spot volcanism, equally did the other neat mountains of the Solar Arrangement, just through rebound during crater formation. Two arcuate scarps ∼5–seven km high on the cardinal uplift propose partial plummet. Collapse features are also observed forth the edges of the Rheasilvia basin, where scarps ∼15–20 km high have slump blocks at their base consistent with collapse.

While the existence of a single south pole basin had been inferred from HST images, topographic maps of Vesta revealed a second basin, named Veneneia (Fig. 7) after one of the founding vestal virgins. Veneneia is ∼400 km in diameter and ∼12 km deep. Rheasilvia is superimposed upon Veneneia and destroys about half of the older structure. Crater counts of the floors of these two large basins suggests ages of ∼one Ga for Rheasiliva and ∼2 Ga for Veneneia (Schenk et al., 2012). In improver to these ii large basins, at least 10 other craters on Vesta exceed fifty km in diameter (Fig. 8), including an older, ∼250 km diameter crater that is also superimposed past Rheasilvia. A general paucity of craters in the south is consistent with resurfacing of much of Vesta by Rheasiliva and Veneneia, while heavily cratered terrains in the north appear to be old, stable surfaces that escaped resurfacing past ejecta from these southern basins. O'Brien et al. (2014) argued that the northern heavily cratered terrain could date to 4.three–4.v Ga, while supporting an historic period of ∼1 Ga for Rheasilvia.

A second unexpected feature of Vesta is the presence of equatorial and northern ridges and troughs (Jaumann et al., 2012). The master gear up of equatorial troughs are wide, apartment-floored and bounded by steep scarps, with lengths varying from 19 to 380 km and upwards to fifteen km in width. In dissimilarity, northern troughs are commencement from the equatorial troughs past about 30° and accomplish lengths upwards to 390 km and widths upwards to 38 km. The features of the northern troughs are more than muted, suggesting an older age of germination. Fitting planes to the ii sets of troughs and determining a pole perpendicular to the center of the plane yields pole directions that are, within error, at the center of the Rheasilvia basin for the equatorial troughs and Veneneia for the northern troughs (Fig. ix). This strongly suggests that the troughs formed equally a outcome of affect deformation during the formation of these basins. Buczkowski et al. (2012) suggest that these troughs are graben and their germination is limited to differentiated bodies, of which Vesta is the smallest, intact differentiated body known in the Solar Organization.

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Advances in determining asteroid chemistries and mineralogies

Thomas H. Burbine , in Geochemistry, 2016

7 Dawn

The Dawn mission was the start spacecraft to orbit two primary-belt asteroids [(four) Vesta and (1) Ceres]. It was also the commencement to visit an intact differentiated asteroid, an original planetesimal from the offset of the solar arrangement and not the fragment of such a body. Dawn was besides the commencement spacecraft to visit a Dwarf Planet. Dawn orbited Vesta from July 2011 to September 2012 and started orbiting Ceres from March 2015.

Instruments on Dawn included a framing camera (FC), visual and infrared spectrometer (VIR), and gamma ray and neutron detector (G). The FC covers 7 wavelengths from 0.438 to 0.961 μm while VIR measured reflectance spectra from 0.25 to 5.one μm. Dawn was the first mission to an asteroid to have a neutron detector, which is used to determine hydrogen abundances and, therefore, the water content.

Images of Vesta (Fig. ten) revealed a heavily cratered Northern Hemisphere and smoother Southern Hemisphere. Two overlapping large craters are present at its Due south Pole with the 500-km wide Rheasilvia crater overlying the 400-km wide Veneneia crater. Diogenite regions are more arable in the Southern Hemisphere (e.g., Reddy et al., 2012b; Thangjam et al., 2013), which is consistent with deeper digging in the Southern Hemisphere due to these large craters. Numerous troughs are also present on Vesta's equator.

Spectral reflectance measurements of Vesta are consistent with HED meteorites with some areas being more than eucritic and some more diogenitic (due east.m., De Sanctis et al., 2012a, 2013; Reddy et al., 2013, 2012b; Thangjam et al., 2013; Ammannito et al., 2013; Zambon et al., 2014). Vesta likewise has a number of terrains that are enriched in depression albedo textile (Reddy et al., 2012a; McCord et al., 2012). These dark areas are by and large associated with impact craters and are spectrally similar to carbonaceous chondrites. They are believed to be due to an influx of carbonaceous material hitting the surface. This was not a surprising effect since HEDs are known to contain CM2-similar and CR2-like inclusions (eastward.k., Buchanan et al., 1993; Zolensky et al., 1996). These inclusions contain arable hydrated silicates. Dark material on Vesta besides was establish to have a feature at ∼0.7 μm (Nathues et al., 2014), which is consequent with CM chondrite material (Cloutis et al., 2011b).

One surprising result for Vesta is the relatively rare occurrence of olivine-rich (>40% wt%) areas on its surface from the assay of FC data (e.chiliad., Ammannito et al., 2013; Thangjam et al., 2014; Nathues et al., 2015). A number of filter reflectance ratios such as the band tilt (R_0.92_μm/R_0.96_μm), mid ratio [(R_0.75_μm/R_0.83_μm) /(R_0.83_μm/R_0.92_μm)], and mid curvature [(R_0.75_μm + R_0.92_μm)/R_0.83_μm], which are based primarily on the work of Isaacson and Pieters (2009) in analyzing lunar spectra, have been used to identify olivine-rich regions (Thangjam et al., 2013, 2014). [R₁₀ is the reflectance at a particular wavelength (x)]. Differentiation of an asteroid is thought to produce a basaltic crust, an olivine-dominated mantle, and a metal iron core. Large craters are nowadays on the surface, which should have broken through the assumed thickness of the basaltic chaff and exposed the olivine-rich mantle. It is possible that the crust is relatively thick on Vesta or an olivine-rich pall did not form on Vesta (Nathues et al., 2015; Le Corre et al., 2015). Nathues et al. (2015) and Le Corre et al. (2015) argue that almost of the olivine on Vesta's surface is endogenic and due to an influx of olivine-rich material striking the surface.

Reddy et al. (2013) discussed the accurateness of compositional interpretations for Vesta's surface based on ground-based and Hubble observations. Basis-based rotational spectra (Gaffey, 1997; Reddy et al., 2010) and Hubble Space Telescope observations (Thomas et al., 1997) previously had noted deeper band depths for the Southern Hemisphere, which is consistent with the Dawn results. A region on the equator with a lower Band Area Ratio that was identified by Gaffey (1997) as being olivine-rich is at present interpreted has being due to impact melt in the ejecta blanket effectually the Oppia crater (Le Corre et al., 2013).

Global Atomic number 26/O (0.30 ± 0.04) and Si/O (0.56 ± 0.06) weight ratios for Vesta derived from gamma ray measurements (Prettyman et al., 2012) are consequent with HEDs. [Prettyman et al. (2012) gives these values every bit mass ratios, which are equivalent to weight ratios]. The Fe/Si weight ratio is 0.54 ± 0.09. These values are also consistent with some angrites, ureilites, and the anomalous Shallowater aubrite; however, none of these meteorites have reflectance spectra similar to Vesta. Iron abundances also vary on Vesta's surface (Yamashita et al., 2013). Measurements of the high-energy gamma ray flux from smaller areas on Vesta's surface are likewise consequent with HEDs (Peplowski et al., 2013) and so is the calculated K/Thursday weight ratio (900 ± 400) (Prettyman et al., 2015). Elements measured on Vesta by Dawn are listed in Table 2.

The neutron detector measures thermal (energies less than 0.1 eV), epithermal (0.1–0.seven MeV), and fast neutrons (>0.7 MeV) from an asteroid's surface (e.grand., Prettyman et al., 2011). As cosmic rays (primarily protons) bombard Vesta's surface, they collide with atoms and dislodge neutrons from their nuclei. These fast-moving neutrons can then collide with other nuclei and lose energy. The lighter the nuclei they strike, the more energy the neutron loses. Since hydrogen has the lowest atomic mass of whatsoever element, abundant hydrogen in the subsurface will significantly "ho-hum" down the neutrons. The relative abundances of thermal, epithermal, and fast neutrons volition exist both a role of the amount of hydrogen and the average diminutive mass of the elements in the surface. The hydrogen is assumed to be a elective of H₂O or single bond OH. Water contents every bit loftier as 400 ppm were calculated for Vesta'southward surface (Lawrence et al., 2013). This consequence is consistent with carbonaceous chondritic fabric on the surface. This result too confirmed the Hasegawa et al. (2003) detection of a weak (∼1%) three μm feature for Vesta, which indicated OH and/or H_iiO-begetting minerals on its surface. Dawn also observed a 2.8 μm absorption due to OH on Vesta'due south surface (De Sanctis et al., 2012b). Curvilinear features on the walls of immature craters accept been proposed (Scully et al., 2015) to be due to the affect release of h2o from deeply cached ice deposits that are too deep to exist detected by One thousand; even so, there is no supporting bear witness that such ice deposits exist on Vesta. Analyses of the fast neutron data (Lawrence et al., 2013) are also consequent with an HED-similar mineralogy on Vesta'southward surface.

Dawn confirmed that Vesta has an HED-like surface composition. Dawn also confirmed that impacts of carbonaceous chondrite projectiles were common and left debris of that limerick on the surface. Nigh HEDs appear to have originated from Vesta and/or the Vestoids. However, a number of eucrite-similar meteorites (Yamaguchi et al., 2002; Gounelle et al., 2009; Scott et al., 2009; Bland et al., 2009) have likewise been discovered with oxygen isotopic compositions singled-out from "typical" HEDs, implying more than than one body formed in the asteroid belt with a basaltic crust. I such asteroid is (1459) Magnya, which has a V-type spectrum (Lazzaro et al., 2000; Hardersen et al., 2004) and orbits the Sun with a semi-major axis of 3.14 AU. (Vesta is located at a semi-major axis of two.36 AU.) Dynamically modeling shows that it is extremely difficult to derive Magnya from Vesta (Michtchenko et al., 2002). A number of other Five-types bodies take as well been identified in the middle and outer main-belt (e.1000., Roig and Gil-Hutton, 2006).

Dawn is currently orbiting the dwarf planet (ane) Ceres in 2015. The exact composition of Ceres has been debated for approximately 40 years (east.yard., Johnson et al., 1975; Chapman et al., 1975; Rivkin et al., 2011) due to difficulties in finding meteoritic spectral matches in the visible and near-infrared. Ceres has long been known to have a 3 μm assimilation band (Lebofsky, 1978), indicating the occurrence of hydrated materials on its surface. But the construction of Ceres'southward 3 μm absorption ring has non been found to exist a very skillful "friction match" for any particular carbonaceous group. Higher resolution spectra in the 3 μm region (Milliken and Rivkin, 2009; Takir et al., 2015) has been interpreted as indicating a mineralogy of hydroxide brucite, magnesium carbonates, and serpentines, which is dissimilar any known meteorite assemblage. However, Brook et al. (2015) argues that the absence of a corresponding brucite band at ∼2.47 μm indicates that this feature on Ceres is not due to brucite. Water vapor has recently been identified (Küppers et al., 2014) around Ceres, apparently indicating water water ice beneath its surface. Bright spots have been observed on the surface of Ceres that could possibly exist due to water water ice (Reddy et al., 2015).

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What Is A Framing Camera

Exploration and Assay of Planetary Shape and Topography Using Stereophotogrammetry

2.1 Framing Cameras

Planets, Asteriods, Comets and The Solar Organisation

2.fourteen.v.7 Dawn

Comparison Sample and Remote-Sensing Information—Agreement Surface Composition

Morphological Imaging

A Brief History of Spacecraft Missions to Asteroids and Protoplanets

1.15 Dawn: 1 Ceres

Comparative studies of meteoroid-planet interaction in the inner solar system

FC colour images of dwarf planet Ceres reveal a complicated geological history

1 Introduction

Asteroid (iv) Vesta II: Exploring a geologically and geochemically circuitous world with the Dawn Mission

4.2 Craters, mountains and troughs

Advances in determining asteroid chemistries and mineralogies

7 Dawn

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