TOEFL-Astronomy-Tpo72 The Impact Origin of Lunar Craters

unanimously

With complete agreement from everyone 一致地；無異議地 Craters were unanimously thought to be volcanic in origin.

topography

The arrangement of natural and artificial physical features of an area 地形 Lunar topography had been studied minutely for centuries.

craters

Bowl-shaped depressions, esp. those made by meteor impacts or volcanoes 隕石坑；火山口 Circular craters dominate the Moon’s surface.

minutely

In great detail; precisely 細緻地；詳盡地 The Moon was examined minutely by generations of observers.

dissenting (voice)

Expressing a different or opposing opinion 持異議的（聲音） Robert Hooke was a dissenting voice against the volcanic model.

postulated

Suggested or assumed as a basis for reasoning 假設；提出 Hooke postulated that impacts formed the craters.

sway

To influence or change someone’s opinion 影響；左右 His idea did little to sway majority opinion.

depth-to-diameter (ratio)

Comparison between a crater’s depth and its width 深徑比 Gilbert analyzed depth-to-diameter ratios of lunar craters.

ratios

Proportional relationships between two quantities 比率 The ratios supported an impact origin.

puddle

A small pool of liquid 水坑 Rock rebound was compared to drops hitting a puddle.

flung out

Thrown out forcefully 被拋出 Material was flung out as impact ejecta.

impact

Collision of a meteor or object with a surface 撞擊；衝擊 Meteor impact can create circular craters.

impact ejecta

Debris expelled during a high-speed collision 撞擊噴射物 Bright rays are formed by impact ejecta.

intact

Unchanged; whole 完好無缺的 The volcanic hypothesis remained intact for decades.

projectiles

Objects (meteors) thrown forward at high speed 拋射體 Large projectiles often vaporize on impact.

vaporize

To change from solid/liquid to gas 汽化 Meteors may vaporize completely on impact.

blast out

To expel violently, like in an explosion 爆破；猛烈噴出 Volcanic gases can blast out large volumes of fragments.

aprons

Fan-shaped deposits of ejecta around a crater （火山／隕石）碎屑坡 Volcanic aprons have first-erupted material at the bottom.

first-erupted

Describing material expelled earliest during an eruption 最先噴出的 Volcanic aprons show first-erupted rocks at the base.

flap

A layer or sheet folded back 翻覆層 Meteor ejecta formed an inverted flap around the rim.

rim

The edge or border of a crater 邊緣；槽口 Drilling through the rim would encounter repeated layers.

strata

Layers of rock 地層 Shoemaker found strata peeled back like petals.

been peeled back

(Layers) folded or rolled away from a center 被掀起；剝離 The strata seemed to have been peeled back from the crater.

shattered

Broken into many pieces 粉碎的；破裂的 Rocks were shattered and cemented by glass.

cemented

Bound together into a solid mass 黏結；膠結 Shattered rocks were cemented by impact-generated glass.

made a case

Presented evidence or arguments in favor of something 提出論據；為…辯證 Shoemaker made a case that Copernicus Crater was an impact site.

Before the decade was out

Before ten years had passed (here: before the 1960s ended) 在這十年結束之前 Before the decade was out, most scientists accepted the impact origin.