"Hello, I was wondering when a comet was due to pass Earth again? When will the next few be? "
Content with the tag: “ammonia”
Abiotic Nitrogen Cycling
ROADMAP OBJECTIVES: 1.1, 1.2, 2.1, 3.1
Chemistry of the NH3/H2O system
ROADMAP OBJECTIVES: 2.2
- 16srrna 17p 79 ceti 85p 1999 1999 and 2000 2000 2008 aas abiogenic abiogenic methane abiotic abiotic synthesis abscicon abundances acid mine drainage acidophile activity adaptive optics adenosine triphosphate aerobic aerosol aerosols akila akilia island algae algal-sarcodine photosymbiotic relationships algal cultures alh84001 alien earths alien life allan hills alpha centauri altiplano alvin amase american astronomical society american type culture collection amino acid amino acids ammonia ammonia formation ammonium amorphization anaerobic analog environments ancient earth ancient pathways. andes and k content anoxia biomarker permian cambrian terrestrial paleosol oxygen archean proterozoic biogeochemistry extinction euxinia hydrogen sulfide sulfur bacteria anoxic environment anoxygenic photosynthesis antarctica antarctic endolithic communities antarctic lakes antartic antartica antennas aqueous alteration archae archaea archaeoglobus archea archean arctic area 9 arid and semi-arid soils aromatic asap (astrobiology sample analysis program) aspartic acid asteroid asteroid 10537 (1991 ry16) asteroids asteroids--dynamics astid astrobiology astrobiology (journal) astrobiology drilling program astrobiology journal astrobiology magazine astrobiotechnology astrochemistry astronaut astronomical journal astrophysical journal astrophysical journal letters astrophysics atacama atacama desert atlantis atmosphere atmosphere escape atmosphere evolution atmospheric airglow atmospheric carbon dioxide atmospheric chemistry atmospheric evolution atmospheric formation atmospheric photochemistry atp-binding proteins australia australian centre for astrobiology autotrophic auv avhrr database awards axial volcano subsurface fluids axis bacteria bacterial metagenomes bacteriorhodopsin banded iron formations basaltic basaltic lava basalt tuff basalt weathering baseball binaries binaries: spectroscopic bioastronomy biochemical adaption biochemistry bioenergetics biofilms biogenic mineral structure biogenic molecules biogeochemical cycles biogeochemistry biogeography biological biomarker biomarkers biome biomimetic synthesis biopan biosignature biosignatures biosphere biosphere-atmosphere interactions biosustaining energy bodonids boethin books borehole brine britian brown dwarfs burgess shale-type ca calcite calcite nano-fibers calcium cambrian canada canyon canyons carbon carbon-13 carbonaceous chondrite carbonate carbonate rocks carbonates carbon chemistry carbon cycle carbon dioxide carbon dioxide ice cargill salt company cassini catalysis catalytic cavity ring-down spectrometer cdna celestial mechanics celestial mechanics – methods: n-body simulations – planets and satellites: general – solar system: celestial mechanics. cells chelation chemical weathering chemin (chemical and mineralogical xrd/xrf instrument) chemoautotrophy chemolithoautotrophs chemostratigraphy chemosynthetic communities chemotrophs chile chimpanzee china chip chiral chirality chlamydomonad chlorophyll concentration chondritic meteorites chrysophyte chrysophytes circumstellar disks circumstellar dust. citations climate climate change climate model climate modeling climate models clouds cnn co-evolution co3 cold environments collaborative technology colors comet cometary comet recovery comets comet wild 2 comics community community software complex life complex organics composition compound specific isotopic analysis computational chemistry conference contamination contamination control continental core accretion cork observatories cosmic rays cosmochemistry countermeasures coupled models cryptoendolith. crystalline water ice curriculum cyanobacteria cycling d/h ratio dance darwin sequence analysis data data analysis database databases data processing techniques dawn ddf decoherence deep-esp deep biosphere deep impact deep impact extended mission deep marine sediments deep subsurface biosphere deep terrestrial biosphere dehydratases dehydrogenases deinococci denitrifcation depthx desulfobulbus desulforhopalus detection methods: transit photometry deuterium deutertation devonian devon island dice dinosaurs director direct planet detection disk-averaged spectra. disk chemistry disks dissimilatory dissimilatory iron reduction distributed temperature sensor diversity dna dna. dna damage dna sequencing dolomite dolphin drilling dune dust dust flux dwarf star dynamical modeling dynamic global vegetation model dynamics e. coli ea early atmosphere early atmospheres early earth early earth geochemistry early evolution of life early life early mars early planetary system evolution early solar system earth earth’s early biosphere earth's early atmosphere earth's water earth-like planets earth and planetary science letters earth and planetary science letters (journal) earth evolution earth formation earthshine east pacific rise eclipsing ecogenomics ecosystem model edax education electric discharge electrochemistry electrocorrosion electronic arts element fractionation el ni�o embedded star formation enceladus encyclopedia of life endosymbiosis endourance endurance england environment environmental chemistry environments enzyme enzymes eoarchean epimerases epoxi erosion esa ethane eubacteria eukaryote eukaryote evolution eukaryotes eukaryotic-specific primers eukaryotic microbial community europa evaporation evaporite evolution evolution and environment exo-planetary systems exobiology exoplanet exoplanets exosolar planets expose express exremophiles extra-solar planets extrasolar life extrasolar planet extrasolar planets extraterrestrial extraterrestrial life extreme conditions extreme environment extreme environments extreme life extremeophiles extremephiles extremophiles faint companion farmer fe fe isotopes femtochemistry fiction fieldwork in april of 1999 in the tinto river located in the huelva district of southwestern spain fingerprint fischer-tropsch catalysis flood fluorescence in situ hybridization focus group formation routes forward contamination fossil fossils fracture frogs functional genomics funding fungi fu orionis fuse future of life galaxies galileo galileo extended mission games ganymede gardening gas gas giants gas phase gene expression general genes genome-genome interaction genome evolution genomes genome sequencing genotype-phenotype geobiology geobiology (journal) geochemical geochemical tca cycle geochemistry geochemsitry geochronology geology geology (journal) geomicrobiology geophysics geysers giant planet models giant planets glacial ice glacier glaciers glutamic acid google google mars gossan graduate students grain growth grain surface chemistry great oxidation even great oxidation event greenhouse effect greenland ground currents groundwater gsfc guaymas basin guerrero negro gullies gypsum habitability habitable planets habitable zone habitablity in the universe habitat hadean halophiles handbook of star forming regions hard materials haughton crater hawaii hawaiian volcanic rocks hawaii team haze hd 46375 hd 209458 hematite heterotrophic flagellates high-lakes high-magnesium calcite high angular resolution high contrast highly siderophile elements high ph historical science holmes homochirality horizontal gene transfer hot spots hot springs hubble human human exploration human factors human lunar mission hydrate hydrocarbons hydrogen hydrogenase hydrogen metabolism hydrogen peroxide hydrogen sulfide hydrothermal hydrothermal redox pathway hydrothermal vent hydrothermal vent organisms hydrothermal vents hydroxylamine hyperion hypersaline hypersaline ecosystems hypersalinity hyperthermophilic ice ice analogs iceland ices icy satellites idaho igneous rocks image processing impact craters impactites impact melt rocks information technology infrared infrared astrophysics infrared imaging inorganic in situ analysis in situ life detection instrumentation instruments international space station interstellar interstellar chemistry interstellar ice interstellar ices. interstellar medium interstellar molecules interviews in vitro evolution ionizing radiation ion microprobe iron iron –sulfides iron-sulfur enzymes iron-sulfur minerals iron concentrations iron formation iron isotope fractionation iron oxide iron oxidizers iron oxidizing bacteria iron reducers iron reduction kinetics irons-sulfur surfaces iron spectromicroscopy irradation irradiation ir spectroscopy isomerases isotope isotopes isotopic fractionation iss issol jack hills jakoba incarcerata jakoba libera jakobids jarosite journal:earth journal: journal of geophysical research journal of bacteriology journal of the american chemical society jpl jupiter kbo kbo size distribution kepler key nutrient metals kuiper belt kuiper belt objects laboratory laboratory investigation laboratory science lake lake bonney lakes landsat tm data laser laser desorption lassen lassen volcanic national park late accretion late bombardment late heavy bombardment ldn 673 left-handed lefty level of analysis lexen program life life and environment life elsewhere in the universe life in extreme life in our solar system life in the universe life on mars light lightning li isotopes lipids liquid liquid chromatography mass spectrometry lithic clasts lithophiles living in the microbial world: summer teacher enhancement - august 1999 lmt low-mass low-mass stars low albedo deposits lunar-like satellites lunar exploration lunar impacts m�ssbauer mafic maghemite magnesite magnet magnetic field magnetic fields magnetic fields - stars magnetite magnets main belt asteroids main belt comets maine malawimonas jakobiformis maps marco polo marine ecology marine sediments eukaryotes mars mars. mars analog mars analog. mars analogs mars analog site mars analogues mars atmosphere mars environmental chamber mars exploration mars express mars glaciers mars global surveyor mars habitability mars life mars maps mars methane mars orbiter mars reconnaissance orbiter mars rovers mars science laboratory mars time mars water martian analogues martian atmosphere martian channels martian dynamo martian meteorites martian oceans mass extinction mass extinctions mbcs mcmurdo dry valleys m dwarfs m dwarf stars media membranes mer mercury messenger metabolic chemistry metabolism first metagenome metagenomics metal isotope fractionation metal sulfides metamorphism meteor meteorite meteorites meteoritic organics meteors meterite meterorites methane methane cycle methanococcus methanogen methanogenesis methanogens methanopyrus methodology mexico micro-oxic environment microbes microbial microbial communities microbial community microbial community population structures microbial diversity microbial ecology microbial ecosystem microbial ecosystems microbial evolution microbial evolutionary processes. microbial geochemistry microbialite microbialites microbial life microbial mat microbial mats microbiology microgravity microlensing microorganisms microscopy mike russell miller-urey miller-urey experiments mineral biosignature mineralogy mirs missions mitochondria mixed cation carbonates mo model interface models mojave molecular-level computer simulations molecular beam molecular biology and evolution (journal) molecular cloud molecular clouds molecular evolution molecular hydrogen molecular mechanics molecular spectroscopy molecular weight molecules molecules of life molybdenum molybdenum isotope fractionation monocarboxylic acids monterey bay moon moon and planets moons mrna mro msl msl (mars science laboratory) m star m stars multi-realizable processes multiple-planet system murchison music mutualism mycobacterium tuberculosis mysql nad nai nai arc team nai asu team nai berkeley team nai cal team nai ciw team nai cub team nai gsfc team nai har team nai hawaii team nai iptai team nai mbl team nai minority institution research support nai mit team nai montana team nai msu team nai postdoctoral fellow nai psu team nai seti team nai ua team nai ucb team nai ucla team nai uh team nai uri team nai uw team nai virus focus group nai vpl at jpl nai vpl at jpl team nai vpl at uw team nai wisconsin team nano-fibers nano-satellite nanoparticles narl nasa arc nasa history nasa jpl nasa tv nasda national parks native american research laboratories nature (journal) ndvi variations near near earth asteroid rendezvous nebular organics neoproterozoic neteritics and planetary science (journal) new horizons new planets new york times nitrate nitrite nitrogenase nitrogen cycle nitrogen cycling nitrogen fixation nitrogen reduction non-el ni�o non-lte effects novel proteins npr ntiric oxide nucleic acids nucleobases numerical simulations obituary ocean ocean-bottom ocean crust ocean drilling program oceans odyssey olympus mons ophiolites opportunity optical microscopy orbital light curves oreos organic organic molecules organics organic synthesis origin of ion channels origin of life origin of transmembrane proteins origins of life origins of protein function orion nebula-like osmium isotopes outer solar system outgassing outreach oven ovens oxidation oxidative stress oxidize acetate anaerobicallly oxygen oxygenic photosynthesis oxygen isotopes ozone ozone production pah paleobiology paleoecology paleoproterozoic paleosol pan-starrs panspermia parachute parasitism past-ecosystem process model past-sea surface temperature past carbon cycle past climate past net primary production pavilion lake pbs pelagophytes pelobionts perchlorate perldbi permafrost permian peroxy defects petrology phage phenotypic changes philosophy phoenix phoenix mission phospholipid fatty acids phosphorus phosphorus limitation photo-dissociation photochemistry photosynthesis photosynthetic photosynthetic communities photsynthesis phyllosilicate phylogenetic phylogeny physiology pigments placozoa planetary accretion planetary disks planetary dynamics planetary formation planetary geology planetary geologyearly biosphere planetary habitability planetary oxidation planetary protection planetary science planetary systems: formation planetary systems: protoplanetary disks planet formation planet formation. planet detection. planetary dynamics. planet migration planets planets and satellites plankton plant-fungal symbioses plants plasticity plate tectonics. playa pnas podcast polar drilling polar wander poles pollen analysis poly(a)-rna polycyclic aromatic hydrocarbons popularization population genetics poster pre–main‐sequence pre-biotic chemistry pre-main sequence stars prebiotic chemistry prebiotic molecules prebiotic soup precambrian precambrian redox environment precambrian research (journal) pre main-sequence - x-rays preservation primer primordial soup probe proceedings of the national academy of sciences (journal) prokaryote prokaryotes propane protein enzymes protein evolution proteins proteobacteria proterozoic proterozoic-cambrian proterozoic doushantuo formation proterozoic nama group proterozoic sediments protiens proto-metabolism protocells protocellular protocellular catalysts protoplanetary disk ps1 psi_blast psychrotolerant public pyrite pyrosequencing pyroxenes and olivine. pyruvic acid quantifying quantum quantum mechanics quartet radiation radiation chemistry radiative-transfer models radiative transfer radiative transfer model radio radioactivity radiolysis radio new york raman microscope raman spectroscopy raman spectroscopy` rdna reclinomonas americana redox redox-sensitive metals redox evolution redox processes reduction remote-sensing remote-sensing techniques remote sensing remote sensing database reptiles ribosomal gene ribosomal rna ribosomal rna phylogeny rio tinto rise of oxygen rna rna display rna world robatic robot robotic robotics robots rover rovers rrna saline salt sam (sample analysis at mars) samples satellites saturn scanning electron microscopy science (journal) scientific american (journal) seafloor weathering search for life sea surface temperature seawater second genesis second life sediment sediment-buried basement sediments seepage erosion segan medal serpentinization shoemaker short-lived radionucleides short-lived radionuclides siderite signatures of life silicon isotopes silurian sims sinkhole skaft��rkatlar lake sleep disruption slime world slime worlds sm-nd snow snowball earth so2 soft materials sogin soil soil moisture soil na soils solar-like young stars solar nebula solar panel solar system solar system: formation solar system chronology solar system ices south africa space shuttle space telescope science institute spark discharge spectral biosignatures spectroscopy spectroscopy. spirit spitzer space telescope spore sr isotopes stability stable isotopes star-formation star and planet formation stardust star formation star forming regions stars stars - x-rays stars: late-type steam atmosphere stellar flares steranes sterols stromatolites student internship sub-permafrost ecosystem subglacial volcanic lake subseafloor subseafloor hyperthermophiles subsurface subsurface biosphere subsurface life subsurface microbiology subterranean plants sulfate sulfate reducing bacteria sulfate reduction sulfide sulfide minerals sulfides sulfidic cave sulfidic mesoproterozoic ocean sulfur sulfuric acid speleogenesis sulfur isotopes sulfur mif summer camp summer school sun sun-earth connection sun-like stars super-earths super earths supergiant star supergiant stars supertrees surface temperature and relative humidity svalbard symbioses symbiosis-specific genes symbiotic synchrotron tardigrade targeted metal uptake tca cycle teachers technology worlds tectonics tega temperate-controlled mineral growth templates temporal frameworks teraforming terraforming terrestrial terrestrial atmospheres terrestrial planet finder (tpf) terrestrial planet formation terrestrial planets terrestrial subsurface thalassicolla nucleata theoretical/computational chemistry thermal and evolved-gas analyzer thermal emission spectrometer thermometer thermophiles thermus/deinococcus thioredoxins tholins time time-of-flight mass spectrometer timescale timetree tinto river titan titanium transiting planets tree of life tree rings tropical rainforest trunk river tubulins tweets twitter u-tube uk ultramafic ultrasmall cells uncultured archaea underwater united kingdom upsilon andromedae uv uv light uv radiation v733 cephei v1647 orionis vegetation vegetation red edge venus video viking viral metagenomes virus viruses visible-near infrared spectroscopy volatile delivery volatile elements volatile exchange volcanoes voyager vysos vysos (variable young stellar objects survey) wall street journal water water on mars water rock interaction weathering web 2.0 website websites well-skeletonized animals wet-chemistry workbook workshop workshop in molecular evolution at woods hole - august 1999 yeast yellowstone young binaries young stellar objects zircon zircons zoe
