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Mars Exploration Program

About: Mars Exploration Program is a(n) research topic. Over the lifetime, 26999 publication(s) have been published within this topic receiving 478839 citation(s). The topic is also known as: MEP & The Mars Exploration Program.

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Open accessJournal ArticleDOI: 10.1029/2000JE001364
Abstract: The Mars Orbiter Laser Altimeter (MOLA), an instrument on the Mars Global Surveyor spacecraft, has measured the topography, surface roughness, and 1.064-μm reflectivity of Mars and the heights of volatile and dust clouds. This paper discusses the function of the MOLA instrument and the acquisition, processing, and correction of observations to produce global data sets. The altimeter measurements have been converted to both gridded and spherical harmonic models for the topography and shape of Mars that have vertical and radial accuracies of ~1 m with respect to the planet's center of mass. The current global topographic grid has a resolution of 1/64° in latitude × 1/32° in longitude (1 × 2 km^2 at the equator). Reconstruction of the locations of incident laser pulses on the Martian surface appears to be at the 100-m spatial accuracy level and results in 2 orders of magnitude improvement in the global geodetic grid of Mars. Global maps of optical pulse width indicative of 100-m-scale surface roughness and 1.064-μm reflectivity with an accuracy of 5% have also been obtained.

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1,325 Citations


Open accessJournal ArticleDOI: 10.1126/SCIENCE.1122659
21 Apr 2006-Science
Abstract: Global mineralogical mapping of Mars by the Observatoire pour la Mineralogie, l'Eau, les Glaces et l'Activite (OMEGA) instrument on the European Space Agency's Mars Express spacecraft provides new information on Mars' geological and climatic history. Phyllosilicates formed by aqueous alteration very early in the planet's history (the "phyllocian" era) are found in the oldest terrains; sulfates were formed in a second era (the "theiikian" era) in an acidic environment. Beginning about 3.5 billion years ago, the last era (the "siderikian") is dominated by the formation of anhydrous ferric oxides in a slow superficial weathering, without liquid water playing a major role across the planet.

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Topics: Mars Exploration Program (64%), Water on Mars (60%), Composition of Mars (58%) ...read more

1,321 Citations


Open accessJournal ArticleDOI: 10.1029/2005JE002605
Abstract: [1] The HiRISE camera features a 0.5 m diameter primary mirror, 12 m effective focal length, and a focal plane system that can acquire images containing up to 28 Gb (gigabits) of data in as little as 6 seconds. HiRISE will provide detailed images (0.25 to 1.3 m/pixel) covering ∼1% of the Martian surface during the 2-year Primary Science Phase (PSP) beginning November 2006. Most images will include color data covering 20% of the potential field of view. A top priority is to acquire ∼1000 stereo pairs and apply precision geometric corrections to enable topographic measurements to better than 25 cm vertical precision. We expect to return more than 12 Tb of HiRISE data during the 2-year PSP, and use pixel binning, conversion from 14 to 8 bit values, and a lossless compression system to increase coverage. HiRISE images are acquired via 14 CCD detectors, each with 2 output channels, and with multiple choices for pixel binning and number of Time Delay and Integration lines. HiRISE will support Mars exploration by locating and characterizing past, present, and future landing sites, unsuccessful landing sites, and past and potentially future rover traverses. We will investigate cratering, volcanism, tectonism, hydrology, sedimentary processes, stratigraphy, aeolian processes, mass wasting, landscape evolution, seasonal processes, climate change, spectrophotometry, glacial and periglacial processes, polar geology, and regolith properties. An Internet Web site (HiWeb) will enable anyone in the world to suggest HiRISE targets on Mars and to easily locate, view, and download HiRISE data products.

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Topics: High Resolution Stereo Camera (56%), Mars Exploration Program (54%), Exploration of Mars (52%) ...read more

1,253 Citations


Open access
10 Jul 1986-
Abstract: A Viking Lander 1 image was modeled as mixtures of reflectance spectra of palagonite dust, gray andesitelike rock, and a coarse rocklike soil. The rocks are covered to varying degrees by dust but otherwise appear unweathered. Rocklike soil occurs as lag deposits in deflation zones around stones and on top of a drift and as a layer in a trench dug by the lander. This soil probably is derived from the rocks by wind abrasion and/or spallation. Dust is the major component of the soil and covers most of the surface. The dust is unrelated spectrally to the rock but is equivalent to the global-scale dust observed telescopically. A new method was developed to model a multispectral image as mixtures of end-member spectra and to compare image spectra directly with laboratory reference spectra. The method for the first time uses shade and secondary illumination effects as spectral end-members; thus the effects of topography and illumination on all scales can be isolated or removed. The image was calibrated absolutely from the laboratory spectra, in close agreement with direct calibrations. The method has broad applications to interpreting multispectral images, including satellite images.

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1,107 Citations


Journal ArticleDOI: 10.1038/26427
24 Sep 1998-Nature
Abstract: Seismology provides a powerful tool for probing planetary interiors1,2, but it has been considered inapplicable to tectonically inactive planets where earthquakes are absent. Here, however, we show that the atmospheres of solid planets are capable of exerting dynamic pressure on their surfaces, thereby exciting free oscillations with amplitudes large enough to be detected by modern broad-band seismographs. Order-of-magnitude estimates of these forces give similar amplitudes of a few nanogals for the Earth, Venus and Mars despite widely varying atmospheric and ambient conditions. The amplitudes are also predicted to have a weak frequency dependence. Our analysis of seismograms, recorded continuously from 1992 to 1993 at 13 globally distributed stations, shows strong evidence for continuously excited fundamental-mode free oscillations on the Earth. This result, together with other recent studies3,4,5, is consistent with our estimate of atmospheric forcing and we therefore propose that it may be possible to detect atmospheric excitation of free oscillations on Venus and Mars as well.

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Topics: Mars Exploration Program (53%), Planet (52%), Venus (52%)

1,042 Citations


Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202222
2021833
2020919
2019973
20181,040
20171,093

Top Attributes

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Topic's top 5 most impactful authors

James W. Head

250 papers, 14.1K citations

Bruce M. Jakosky

242 papers, 12.1K citations

James F. Bell

206 papers, 9.7K citations

Ronald Greeley

174 papers, 7.5K citations

François Forget

166 papers, 7.7K citations

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