ライフサイエンスコーパス: crater

1 ed the South Pole/Aitken basin or asymmetric cratering).

2 ilometers close to the 50-kilometer Ernutet crater.

3 side the 150-kilometer-diameter Gale impact crater.

4 environment fed by rivers draining into the crater.

5 ble gases in a mudstone on the floor of Gale Crater.

6 il from the Rocknest aeolian bedform in Gale crater.

7 he 35-million-year-old Chesapeake Bay impact crater.

8 phur, chlorine and zinc) to soils from Gusev crater.

9 he deposit, including outliers close to Gale crater.

10 ight percent) in the Columbia Hills of Gusev crater.

11 cient volcanic hydrothermal setting in Gusev crater.

12 and drilled sedimentary deposits within Gale crater.

13 crater morphology as that of asteroid impact craters.

14 gs, such as near volcanic activity or impact craters.

15 s, crater central peaks, and numerous simple craters.

16 een excavated from 3 to 7 km diameter impact craters.

17 issue and estimate the depth of the ablation craters.

18 existence of crosscut small-diameter impact craters.

19 h latitudes and at several fresh feldspathic craters.

20 to characterize the bottoms of these sputter craters.

21 ce of shocked minerals, tektites, and impact craters.

22 tural relationships with small, young impact craters.

23 d is found mostly in the bottoms of cup-like craters.

24 t mid-latitude gullies and equatorial impact craters.

25 stribution, and an apparent absence of large craters.

26 ould have an icy crust with few or no impact craters.

27 d monitor the morphology of resulting impact craters.

28 hereas the farside is mountainous and deeply cratered.

29 surface cannot solely be explained by impact cratering.

30 ly triggered by bolide impacts, resulting in craters ~30 km in diameter and occurring perhaps a few m

31 The simulated impact produced a transient crater, ~390 kilometers in diameter, that was not mainta

32 tunity has investigated the rim of Endeavour Crater, a large ancient impact crater on Mars.

33 masked and fades into the background as the craters age.

34 l tens of millions of years, consistent with crater ages.

35 Mars rover Opportunity has explored Victoria crater, an approximately 750-meter eroded impact crater

36 Surface rocks from the Gusev crater analysed by the Spirit rover are much older (abou

37 ced inward from the wall, infilling both the crater and an internal lake basin to a thickness of at l

38 st 15% of the surface and is concentrated in crater and basin ejecta.

39 urface, it imaged a 25- to-30-meter-diameter crater and evidence of a high-angle ballistic ejecta plu

40 is constrained by the formation of Victoria crater and their minimum age by erosion of the meteorite

41 temporal dataset, we detected 222 new impact craters and found 33 per cent more craters (with diamete

42 ndom creases and craters to aligned creases, craters and lines, and the size of the pattern from mill

43 However, although studies of existing craters and returned samples offer insight into the proc

44 es include both those associated with impact craters and those that do not appear to have any correla

45 quency and associated water volumes in Istok crater, and show that debris flows occurred at Earth-lik

46 n be related to the history of volcanism and cratering, and the total contractional strain is at leas

47 known on Earth only in meteorites and impact craters, and its presence strongly supports a cosmic imp

48 of relief, the number of superimposed small craters, and the 'freshness' (spectral maturity) of the

49 ce, lack of superposed large-diameter impact craters, and the existence of crosscut small-diameter im

50 helix forms a major part of the ISP binding crater, any positional shift of this helix modulates the

51 These dark materials, often associated with craters, appear in ejecta and crater walls, and their py

52 e heavily cratered, but the largest expected craters are absent.

53 have favored relaxation, yet large unrelaxed craters are also present.

54 the bottoms of the Cs(+) and O(2)(+) sputter craters are significantly rougher.

55 Impact craters are the most obvious indication of asteroid impa

56 erved rate, implying that surfaces devoid of craters are truly young and that as yet unrecognized pro

57 products from a known cosmic impact (Meteor Crater, Arizona) and from the 1945 Trinity nuclear airbu

58 Rimmed grooves, lineations and elongate craters around Mare Imbrium shape much of the nearside M

59 ciding with a long-lived lake system in Gale Crater at approximately 3.5 Ga.

60 soil along the rim of a 450-m diameter fresh crater at the Chang'e-3 (CE-3) landing site, investigate

61 New impact craters at five sites in the martian mid-latitudes excav

62 Craters at most of these sites may have excavated comple

63 rater wall, and similar occurrences in other craters at these latitudes on Mars, shows that they are

64 h distinct material exposed at several fresh craters becomes gradually masked and fades into the back

65 In general, the wedge-crater beveling protocol is shown to provide a powerful

66 ed between 90 and 300 K using a unique wedge-crater beveling strategy that allows these parameters to

67 Surface roughness at the SIMS crater bottoms is characterized by AFM as a function of

68 ovinces and the ancient population of impact craters buried beneath the young lowlands surface sugges

69 Parts of Ceres' surface are heavily cratered, but the largest expected craters are absent.

70 rounding terrain and the interiors of nearby craters, but not as bright as the interior walls.

71 The dwarf planet is dominated by numerous craters, but other features are also common.

72 nergy and length difference, granular impact cratering by liquid drops follows the same energy scalin

73 l explored, our knowledge on granular impact cratering by liquid drops is still very limited.

74 Although the mechanism of granular impact cratering by solid spheres is well explored, our knowled

75 he high porosity may enhance preservation of craters by minimizing the amount of ejecta produced or r

76 shadowed region within the lunar south pole crater Cabeus, ejecting debris, dust, and vapor.

77 show that the material near the edge of the crater can be ejected with low internal energies and tha

78 rmation about an impact even when the source crater cannot be found.

79 summit of Nafanua, venting elsewhere in the crater causes mass mortality.

80 structures, volcanic landforms, basin rings, crater central peaks, and numerous simple craters.

81 The host rocks, which are associated with crater central peaks, peak rings, floors, and walls, are

82 The 7.5-km wide Lockne crater, central Sweden, is known to be a member of this

83 tly imprint Phobos with linear, low-velocity crater chains (catenae) that match the geometry and morp

84 hobos is criss-crossed by linear grooves and crater chains whose origin is unexplained.

85 Multiring basins, large impact craters characterized by multiple concentric topographic

86 Applying a recent model for early lunar crater chronology and an updated dynamical extrapolation

87 ates reproduce impact spherule bed and lunar crater constraints.

88 y lead to an accretionary pile rather than a crater, contributing a hemispheric layer of extent and t

89 By impact crater counting chronology we estimated the age of the s

90 Crater counts and radiometric ages from returned samples

91 tion I292A on the surface of the ISP-binding crater decreased k1 to 4400 s-1, while the addition of f

92 g color and albedo contrasts have comparable crater densities and therefore similar ages.

93 Crater densities on Nix and Hydra imply surface ages of

94 Smooth plains exterior to Caloris exhibit a crater density approximately 40% less than on interior p

95 fference in elevation, crustal thickness and crater density between the southern highlands and northe

96 Although their size and impact crater density indicate continued activity over billions

97 ensitivity of the primary ion was its impact crater depth or the amount of surface erosion.

98 eters related to surface sensitivity (impact crater depth, implantation depth, and molecular escape d

99 oms is characterized by AFM as a function of crater depth.

100 aster array (50 mum pitch distance, ablation crater diameter of approximately 20 mum).

101 a heavily cratered surface, a heterogeneous crater distribution, and an apparent absence of large cr

102 This newly discovered crater doublet provides a unique reference for impacts b

103 e, we show a significant depletion of cerean craters down to 100-150 km in diameter.

104 The main displacement mechanism is along the crater edge.

105 but spatially restricted units include fresh crater ejecta less affected by space weathering than oth

106 iments and impact models, however, show that crater ejecta velocities are typically greater than seve

107 mature surface materials as well as immature crater ejecta, which suggests that the ferrous iron cont

108 layers created by Chicxulub-sized or larger cratering events4.

109 veal that many bright deposits within impact craters exhibit fresh-appearing, irregular, shallow, rim

110 Numerous craters exhibit polygonal shapes, terraces, flowlike fea

111 nd velocities of the ejecta from this unique cratering experiment are better constrained.

112 e structure indicates that compaction of the crater fill influenced long-term sedimentation patterns

113 y connate water of the target remains in the crater fill today, where it poses a potential threat to

114 The moat and crater floor around the new volcano are littered with de

115 The relatively brighter crater floor is most simply explained by decreased space

116 all to cause glacial flow and filling of the crater floor with debris-covered glaciers.

117 Crater floors vary in roughness and slope, implying comp

118 rted by geomorphologic features such as flat crater floors with pits, lobate flows of materials, and

119 ials; high-reflectance deposits seen in some crater floors; and moderately high-reflectance, relative

120 ed samples offer insight into the process of crater formation and the past cratering rate, questions

121 rmed from the dynamic uplift of rocks during crater formation.

122 er, an approximately 750-meter eroded impact crater formed in sulfate-rich sedimentary rocks.

123 ttle floor deposition has occurred since the crater formed more than three billion years ago.

124 e 0.7-km diameter, contemporaneous, Malingen crater, formed by the impact of a binary, presumably 'ru

125 ted to have been excavated from depth by the crater-forming process.

126 xide, made in the martian atmosphere at Gale Crater from the Curiosity rover using the Sample Analysi

127 derived from topography maps of single pulse craters from atomic force microscopy.

128 ver, Ceres' surface appears devoid of impact craters > approximately 280 km.

129 he Moon, we produced a catalog of all impact craters >/=20 kilometers in diameter on the lunar surfac

130 mordial main belt of asteroids predict 10-15 craters >400 km should have formed on Ceres, the largest

131 icate that a significant population of large craters has been obliterated, implying that long-wavelen

132 for the origin of increased salinity in the crater have included evaporite dissolution, osmosis and

133 is therefore widely assumed that only impact craters have reshaped the lunar landscape over the past

134 ters over gently sloping plains and boundary cratered highlands, as well as backwash channels where w

135 is an intensely eroded deposit north of the cratered highlands.

136 at Gusev Crater, Meridiani Planum, and Gale Crater implies locally sourced, globally similar basalti

137 rticles in aerogel and from residue in seven craters in aluminum foil that was collected during passa

138 apping of Mars suggest derivation from small craters in terrains of Amazonian to Hesperian age.

139 ilicate in rims, ejecta and central peaks of craters in the southern highland Noachian cratered terra

140 r CheMin X-ray diffraction results from Gale crater indicate that the crystallinity of Martian sedime

141 n was found in the O(2)(+) and Cs(+) sputter craters, indicating extensive decomposition of the sucro

142 Shackleton crater is nearly coincident with the Moon's south pole.

143 indicate that groundwater in the Chesapeake crater is remnant Early Cretaceous North Atlantic (ECNA)

144 The morphology of some impact craters is consistent with ice in the subsurface, which

145 The overall scarcity of recognizable large craters is incompatible with collisional models, even in

146 We find that the roughness in SIMS craters is limited to approximately 1.5 nm, which is muc

147 raphically isolated radiations of Nicaraguan crater lake cichlid fishes.

148 on a sympatrically diverging species pair of crater lake cichlid fishes.

149 Neotropical crater lake cichlids are ideal models to study evolution

150 ies adaptive radiations such as the Cameroon crater lake cichlids, existing models have focused on bi

151 e past 25 000 years from Lake Challa, a deep crater lake in equatorial East Africa.

152 in a small (700 meters in diameter) isolated crater lake in Tanzania.

153 IL, Mingo, MO, Phoenix, AZ, San Gabriel, CA, Crater Lake National Park, OR, and Spokane, WA.

154 mean, 22 +/- 9.5 minutes) to a high-altitude crater lake.

155 Until recently, Uganda's crater lakes were considered schistosomiasis free due to

156 e only comparable to those found in volcanic crater lakes.

157 l radiation events within and among isolated crater lakes.

158 The ejected nonvolatile debris and the crater left behind were examined by circular dichroism,

159 These terrains have a lower density of craters less than 100 km in diameter than does the Moon,

160 ms like a liquid yet it preserves a circular crater like a solid.

161 A unique three-dimensional, crater-like microstructure was also observed in authenti

162 For example, we show that catena-producing craters likely formed in the gravity regime, providing c

163 Several irregularly shaped craters located within Arabia Terra, Mars, represent a n

164 ) is similar to pyroclastic rocks from Gusev crater, Mars, and consistent with widespread distributio

165 d mudstone (Buckskin) at Marias Pass in Gale crater, Mars, by the Chemistry and Mineralogy X-ray diff

166 ugh organic matter has been detected at Gale Crater, Mars, its concentrations are lower than expected

167 riosity rover at Yellowknife Bay within Gale crater, Mars.

168 The size distribution of smooth-plains craters matches that of lunar craters postdating the Lat

169 jecta velocity field and knowledge of source crater material properties.

170 Radial graben and a floor-fractured crater may indicate intrusive activity.

171 ts for Rhodamine B show that very consistent craters may be generated.

172 oils and aeolian materials analyzed at Gusev Crater, Meridiani Planum, and Gale Crater implies locall

173 Crater morphology and simple-to-complex crater transitio

174 same energy scaling and reproduces the same crater morphology as that of asteroid impact craters.

175 re as follows: cave (mostly hapten binders), crater (mostly protein and peptide/carbohydrate/nucleic

176 the uppermost layered materials on the Gale crater mound.

177 was recently found to have two large impact craters near its south pole, exposing subsurface materia

178 d by the sharp contrast between the sparsely cratered northern lowland plains and the heavily cratere

179 mission signature 90 seconds after the Lunar Crater Observation and Sensing Satellite (LCROSS) Centau

180 The Lunar CRater Observation and Sensing Satellite (LCROSS) missio

181 The Lunar Crater Observation and Sensing Satellite (LCROSS) missio

182 On 9 October 2009, the Lunar Crater Observation and Sensing Satellite (LCROSS) sent a

183 e surface, instruments on the trailing Lunar Crater Observation and Sensing Satellite (LCROSS) Shephe

184 The Lunar Crater Observation and Sensing Satellite (LCROSS) struck

185 lar interest is a bright pit on the floor of crater Occator that exhibits probable sublimation of wat

186 volcanic cone, named Nafanua, in the summit crater of Vailulu'u seamount.

187 terminal' bombardment that culminated in the cratering of the Moon.

188 ice may be presented in permanently shadowed craters of the Moon.

189 thography to pattern surfaces with nanoscale craters of various aspect ratios and pitches, we show th

190 , including that in the K-T Chicxulub impact crater on Earth.

191 eralogy of certain basaltic rocks from Gusev crater on Mars and of martian basaltic meteorites.

192 The landforms of northern Gale crater on Mars expose thick sequences of sedimentary roc

193 of Endeavour Crater, a large ancient impact crater on Mars.

194 Home Plate is a layered plateau in Gusev crater on Mars.

195 obvious indication of asteroid impacts, but craters on Earth are quickly obscured or destroyed by su

196 hy similar to that observed at similar-sized craters on Earth.

197 qual to 8 to 10 kilometers, secondary impact craters on Mercury are more abundant than primaries; thi

198 Sampled craters on Mercury are shallower than their counterparts

199 s and size-frequency distributions of impact craters on Mercury imaged during MESSENGER's first flyby

200 the basin's interior plains includes embayed craters on the basin floor and diffuse deposits surround

201 around 70 and four Chicxulub-sized or larger craters on the Earth and Moon, respectively, between 1.7

202 We report counts of impact craters on the MFF units that have implications for our

203 A low density of craters on the peak-ring basin Raditladi implies that it

204 We predict that the distribution of impact craters on the surface will not show the usual leading h

205 Sedimentary rocks at Yellowknife Bay (Gale crater) on Mars include mudstone sampled by the Curiosit

206 SS) sent a kinetic impactor to strike Cabeus crater, on a mission to search for water ice and other v

207 e in Oxo, a 10-kilometer, geologically fresh crater, on five occasions over a period of 1 month.

208 analysis of zircaloy sample while creating a crater only 10 mum in diameter.

209 entrated deposits of water ice in Shackleton crater or elsewhere at the south pole.

210 roids that produced many young lunar basins (craters over 300 kilometres in diameter) has frequently

211 The accumulation of impact craters over time is of fundamental use in evaluating th

212 ientale Basin, locally modified the prebasin crater population to ~2 basin radii from the basin cente

213 Impact crater populations on Pluto and Charon are not consisten

214 The characteristics of pre- and postmare crater populations support the hypothesis that there wer

215 The most-densely cratered portion of the highlands reached a state of sat

216 These plains are sparsely cratered, postdate the formation of the basin, apparentl

217 smooth-plains craters matches that of lunar craters postdating the Late Heavy Bombardment, implying

218 thin an exhumed alluvial fan complex in Gale Crater, presents some of the most compelling evidence ye

219 We also observe a secondary cratering process that we estimate churns the top two ce

220 roughness variations cannot be explained by cratering processes only.

221 e pairs to quantify the contemporary rate of crater production on the Moon, to reveal previously unkn

222 tions still remain about the present rate of crater production, the effect of early-stage jetting dur

223 e processes, viz., LA sampling (via ablation crater profiles [ACP]) and aerosol washout/transfer/ICPM

224 d data that establish the present-day impact cratering rate and document new deposits formed by downs

225 onsequences for the meteorite production and cratering rate during several millions of years followin

226 The terrestrial and lunar cratering rate is often assumed to have been nearly cons

227 ues predicted by models that scale the lunar cratering rate to Mars are close to the observed rate, i

228 the process of crater formation and the past cratering rate, questions still remain about the present

229 Resultant sputter craters reached depths of approximately 2 microm and pos

230 Results show that Vesta's cratering record has a strong north-south dichotomy.

231 , a result that reflects the preservation of crater relief in highly fractured crust.

232 These craters represent a new membrane feature resulting from

233 well under the ten-million-year upper-limit crater retention age for Sputnik Planum.

234 involved in convection and advection, with a crater retention age no greater than ~10 million years.

235 ater SFD has been used to estimate a surface crater retention age of approximately 1.6 +/- 0.3 Gyr.

236 nce Laboratory Mast Camera (Mastcam) in Gale crater reveal isolated outcrops of cemented pebbles (2 t

237 Absolute model ages from impact craters reveal that extrusion of the dome has occurred r

238 ly wet climate that supplied moisture to the crater rim and transported sediment via streams into the

239 e expected antiquity of rocks comprising the crater rim.

240 veins cut sedimentary rocks adjacent to the crater rim.

241 s, and meteoritic debris is present near the crater rim.

242 In addition, the cumulative crater SFD has been used to estimate a surface crater re

243 sample stage designs often lead to variable crater shapes.

244 that have been dismissed as degraded impact craters should be reconsidered as possible volcanic cons

245 ions of a typical midlatitude Martian impact crater show that gully formation follows a geologically

246 As crater size increases, central peaks transition to peak

247 We characterized PIRL crater size using agar films containing Rhodamine.

248 o result from imprecise determination of the crater size when ablating the glass SRM.

249 tional evidence from color images and impact crater size-frequency distributions, support a volcanic

250 degrees C from samples of Hesperian-era Gale crater smectite to determine this isotope ratio.

251 ered northern lowland plains and the heavily cratered southern highlands.

252 Here we report global crater statistics of Mercury's most heavily cratered ter

253 e temporally distinguishable on the basis of crater statistics.

254 re of endogenic activity, rather than impact craters such as those on planetary and asteroid surfaces

255 by the Dawn spacecraft that reveal a heavily cratered surface, a heterogeneous crater distribution, a

256 of craters in the southern highland Noachian cratered terrain indicate excavation of altered crust fr

257 The ancient cratered terrain of the southern highlands of Mars is th

258 aqueous alteration of basalt of the ancient cratered terrain.

259 The most heavily cratered terrains on Mercury have been estimated to be a

260 crater statistics of Mercury's most heavily cratered terrains on the entire surface.

261 Vesta's northern heavily cratered terrains retain much of their earliest history.

262 Pluto also has ancient cratered terrains up to ~4 billion years old that are ex

263 water ice, producing haze clouds inside the crater that appear and disappear with a diurnal rhythm.

264 re is no preserved evidence of the transient crater that would reveal the basin's maximum volume, but

265 ad reflectance zones associated with the new craters that we interpret as evidence of a surface-bound

266 Under stagnant conditions near the crater, the extent of SO2 oxidation was substantially hi

267 reference sample to check the sample erosion crater, the sample stage movement and memory effects.

268 material ablated from submicrometer diameter craters, the effective lateral resolution is currently l

269 res, and partially or completely bury impact craters, the sizes of which indicate plains thicknesses

270 Adding extensive ablation in the treatment crater to compensate for inadequate excision should be a

271 pattern can be tuned from random creases and craters to aligned creases, craters and lines, and the s

272 stinctive reimpact patterns allow sesquinary craters to be traced back to their source, for the first

273 inside and adjacent to numerous large impact craters, to thicknesses in excess of several kilometers.

274 Crater morphology and simple-to-complex crater transition diameters indicate that the crust of C

275 surface density of relatively well-preserved craters two to ten kilometres across.

276 considered to be derived from young, lightly cratered volcanic regions, such as the Tharsis plateau.

277 Degradation of the crater wall and rim probably supplied these sediments, w

278 snow and ice accumulated on the pole-facing crater wall to cause glacial flow and filling of the cra

279 the insolation geometry of this pole-facing crater wall, and similar occurrences in other craters at

280 al phases are possibly sourced from the Gale crater wall/rim/central peak.

281 Layering in the crater walls preserves evidence of ancient wind-blown du

282 were etched using He LTP, and the resulting crater walls were depth profiled using time-of-flight se

283 act-related stratigraphy is preserved in the crater walls, and meteoritic debris is present near the

284 ssociated with craters, appear in ejecta and crater walls, and their pyroxene absorption strengths ar

285 recent aqueous activity in some mid-latitude craters was much more frequent than previously anticipat

286 g a smooth region associated with the Kerwan crater, we determined absolute model ages (AMAs) of 550

287 t Mars instrument suite on Curiosity at Gale crater, we report detection of background levels of atmo

288 The deposits in Gale crater were then exhumed, probably by wind-driven erosio

289 lies at and near the cell periphery, whereas craters were observed on the central membrane lacking F-

290 cks on the rim of the Noachian age Endeavour crater, where orbital spectral reflectance signatures in

291 terrain is associated with numerous martian craters, where pits are thought to form through degassin

292 ttle chemical change in the C(60)(+) sputter crater, while considerable amorphous carbon was found in

293 w a very flat bottom in the C(60)(+) sputter crater, while the bottoms of the Cs(+) and O(2)(+) sputt

294 an ancient, unusually well-preserved simple crater whose interior walls are fresher than its floor a

295 ngwoodite grains, we infer an initial impact crater with ~90 km diameter, with a factor of 2 uncertai

296 trast, Bi(5)(+2) primary ions created impact craters with a depth of 1.8 nm in tetraglyme films and w

297 ions, Bi(1)(+) and C(60)(+2), created impact craters with depths of 0.3 and 1.0 nm, respectively, in

298 with strong ammonia absorption tied to small craters with relatively fresh-appearing impact ejecta.

299 ew impact craters and found 33 per cent more craters (with diameters of at least ten metres) than pre

300 pressions found in and around several impact craters, with a distinct morphology not observed on othe