为什么地球有板块构造而其他行星似乎没有？
Why does Earth have plate tectonics while other planets seem not to?
地球有足够的质量维持内部热量、又有充足的地表水润滑岩石圈，使刚性板块得以破裂并缓慢移动。金星可能曾有过但已停滞，火星则因体积小冷却太快而早早停止。水的存在和适宜大小被认为是地球板块运动的关键。
Earth is massive enough to keep internal heat and has abundant surface water to lubricate the lithosphere, letting rigid plates break and drift. Venus may have had tectonics that stalled, while small Mars cooled too fast and stopped early. Water and the right size are thought key to Earth's plates.
难度 专业 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
苏宜,《天文学新概论》第5版,科学出版社
Su Yi, Introduction to Astronomy, 5th ed., Science Press
独立核验依据 · Independent verification: 核验依据 2 ISBN 9787030620477（豆瓣书目条目: 天文学新概论）
#板块构造 #地球 #地质
太阳系内行星和外行星为什么会如此不同？
Why are the inner and outer solar system planets so different?
太阳形成后，年轻太阳的辐射和太阳风把内侧的挥发性物质（水、气体）吹向外侧，使内区只留下耐热的岩石金属，形成小而密的类地行星。外区较冷，能积累大量氢氦成为气态巨行星。这种由温度梯度决定的物质分异塑造了行星布局。
After the Sun formed, its radiation and wind blew volatile materials like water and gas outward, leaving only heat-resistant rock and metal in the inner region to make small dense terrestrial planets. The cooler outer region accumulated hydrogen and helium into gas giants. This temperature-driven segregation shaped the planetary layout.
难度 专业 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
苏宜,《天文学新概论》第5版,科学出版社
Su Yi, Introduction to Astronomy, 5th ed., Science Press
独立核验依据 · Independent verification: 核验依据 2 ISBN 9787030620477（豆瓣书目条目: 天文学新概论）
#内行星 #外行星 #分异
柯克伍德空隙是怎样由轨道共振形成的？
How do orbital resonances create the Kirkwood gaps in the asteroid belt?
小行星主带中某些轨道周期与木星呈简单整数比，例如3:1共振，反复受木星摄动而获得能量。这种累积作用把小行星推离原轨道，清空出特定的半长径区间，形成空隙。威斯登在1982年用混沌动力学解释了这些空隙为何长期稳定存在。
In the main asteroid belt, certain orbits have periods in simple integer ratios with Jupiter, such as the 3:1 resonance, and repeated Jupiter perturbations pump energy into them. The accumulated effect nudges asteroids out of their original orbits, clearing specific semimajor-axis ranges into gaps. Wisdom explained in 1982 why chaotic dynamics keeps these gaps stable over time.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 来源待核验 · Source pending review
来源 · Source
出处备注：著录含书名，但缺版次 / 出版社 / 年份中的一部分，需编辑补全后才能做独立比对。
Kirkwood（1866）原始观测；Wisdom《Chaotic behavior in the asteroid belt》（1982，AJ）；NASA/JPL 太阳系动力学组
Kirkwood (1866) original observation; Wisdom, Chaotic behavior in the asteroid belt (1982, AJ); NASA/JPL Solar System Dynamics
#柯克伍德空隙 #轨道共振 #小行星带
水星体积很小，为何却拥有全球性的磁场？
Given its small size, why does Mercury nonetheless possess a global magnetic field?
水星的外核仍是部分熔融的液态铁镍，加上缓慢自转与足够的热对流，维持着一个微弱但真实的偶极磁场。信使号探测发现其磁场仅为地球的约百分之一，且磁轴相对自转轴明显偏移。这一磁场能部分偏转太阳风，在背阳侧形成小型磁层。
Mercury's outer core remains partly molten liquid iron-nickel, and with slow rotation and sufficient thermal convection it sustains a weak but genuine dipolar field. The MESSENGER mission found the field is only about one percent of Earth's and significantly offset from the spin axis. It still partly deflects the solar wind, producing a small magnetosphere on the planet's night side.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
苏宜,《天文学新概论》第5版,科学出版社
Su Yi, Introduction to Astronomy, 5th ed., Science Press
独立核验依据 · Independent verification: 核验依据 2 ISBN 9787030620477（豆瓣书目条目: 天文学新概论）
#水星 #行星磁场 #液态外核
行星是如何从尘埃和气体聚集形成的？
How do planets form from dust and gas?
在恒星周围的原始星盘中，微米级尘埃通过碰撞黏结成更大的颗粒，再经引力吸积长成星子，最终形成行星胚胎和行星，这一过程叫吸积。内侧岩质行星靠固体物质堆积，外侧巨行星先形成核再俘获气体。吸积理论能解释行星大小分布和轨道特征。
In a protoplanetary disk, micron-sized dust sticks into bigger grains through collisions, then grows by gravitational accretion into planetesimals and finally planets, a process called accretion. Inner rocky planets build from solids, while outer giants form cores that then capture gas. Accretion theory explains planet sizes and orbits.
难度 专业 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
苏宜,《天文学新概论》第5版,科学出版社
Su Yi, Introduction to Astronomy, 5th ed., Science Press
独立核验依据 · Independent verification: 核验依据 2 ISBN 9787030620477（豆瓣书目条目: 天文学新概论）
#吸积 #星子 #行星形成
我们如何探测太阳系外的行星？
How do we detect planets around other stars?
主要方法有两种：凌星法观测行星遮住恒星时亮度的细微下降，径向速度法测量行星引力使恒星产生的微小摆动。此外还有直接成像、微引力透镜等。这些方法让我们已发现数千颗系外行星，并评估其是否位于宜居带。
The main methods are the transit method, watching tiny brightness dips as a planet crosses its star, and the radial-velocity method, measuring the star's tiny wobble from the planet's gravity. Direct imaging and microlensing also help. They have revealed thousands of exoplanets and let us assess habitable-zone candidates.
难度 专业 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
苏宜,《天文学新概论》第5版,科学出版社
Su Yi, Introduction to Astronomy, 5th ed., Science Press
独立核验依据 · Independent verification: 核验依据 2 ISBN 9787030620477（豆瓣书目条目: 天文学新概论）
#系外行星 #凌星法 #径向速度
国际天文学联合会如何定义『行星』？
How does the IAU define a 'planet'?
按2006年定义，行星必须：绕太阳公转、自身重力使其呈近似球形、并已清空轨道附近的其他天体。太阳系中满足这三条的只有水星、金星、地球、火星、木星、土星、天王星、海王星八颗。矮行星因未清空轨道而不在此列。
Since 2006 a planet must orbit the Sun, be nearly round under its own gravity, and have cleared its orbital neighborhood. Only Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune meet all three. Dwarf planets fail the last test and are excluded.
难度 进阶 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
苏宜,《天文学新概论》第5版,科学出版社
Su Yi, Introduction to Astronomy, 5th ed., Science Press
独立核验依据 · Independent verification: 核验依据 2 ISBN 9787030620477（豆瓣书目条目: 天文学新概论）
#行星 #定义 #太阳系
土卫六上的甲烷循环与地球的什么过程相似？
How is the methane cycle on Titan similar to a process on Earth?
土卫六拥有浓密的大气与低温表面，甲烷在那里像水一样蒸发、凝结并形成降雨，汇入湖泊与河流。卡西尼号探测到液态甲烷湖和季节性云系，显示出一个以甲烷为工作流体的完整水文循环。它与地球水循环机制相同，只是工作物质从水换成了甲烷，温度低了近200开尔文。
Titan has a thick atmosphere and a frigid surface where methane evaporates, condenses into clouds, and falls as rain that feeds lakes and rivers. The Cassini-Huygens mission detected liquid methane lakes and seasonal clouds, revealing a complete hydrological cycle using methane as the working fluid. The mechanism mirrors Earth's water cycle exactly, only with methane instead of water and temperatures nearly 200 kelvin lower.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
苏宜,《天文学新概论》第5版,科学出版社
Su Yi, Introduction to Astronomy, 5th ed., Science Press
独立核验依据 · Independent verification: 核验依据 2 ISBN 9787030620477（豆瓣书目条目: 天文学新概论）
#土卫六 #甲烷循环 #水文循环
土卫二的冰喷泉为何让科学家认为它地下可能存在海洋？
Why do Enceladus's ice plumes lead scientists to suspect a subsurface ocean?
卡西尼号飞越土卫二南极的羽流时，探测到含盐的冰粒和简单有机物，说明物质来自与岩石接触的液态水体。羽流由卫星内部潮汐加热维持，喷口下的冰壳之下被认为存在一个全球性咸水海洋。这一组合使土卫二成为搜寻地外生命最有潜力的目标之一。
When Cassini flew through Enceladus's south-polar plumes, it found salty ice grains and simple organic molecules, indicating material from a liquid reservoir in contact with rock. Tidal heating within the moon sustains the plumes, and a global salty ocean is thought to lie beneath the icy shell. That combination makes Enceladus one of the most promising places to search for extraterrestrial life.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
苏宜,《天文学新概论》第5版,科学出版社
Su Yi, Introduction to Astronomy, 5th ed., Science Press
独立核验依据 · Independent verification: 核验依据 2 ISBN 9787030620477（豆瓣书目条目: 天文学新概论）
#土卫二 #冰喷泉 #地下海洋
太阳系其他行星上也有火山活动吗？
Do other planets in the solar system have volcanoes?
有。木卫一的火山活动比地球还剧烈，不断喷发硫和二氧化硫；金星上的大型盾状火山可能仍偶尔活动。火星的奥林匹斯山虽已沉寂，但表明火星历史上曾有过强烈火山作用。火山是行星演化的重要标志。
Yes. Jupiter's moon Io is even more volcanically active than Earth, erupting sulfur and sulfur dioxide; Venus has huge shield volcanoes that may still erupt occasionally. Mars's Olympus Mons is dormant but shows the planet was once violently volcanic. Volcanoes are key markers of planetary evolution.
难度 进阶 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
苏宜,《天文学新概论》第5版,科学出版社
Su Yi, Introduction to Astronomy, 5th ed., Science Press
独立核验依据 · Independent verification: 核验依据 2 ISBN 9787030620477（豆瓣书目条目: 天文学新概论）
#火山 #木卫一 #金星
什么是恒星的宜居带？
What is a star's habitable zone?
宜居带是恒星周围温度适中、允许液态水存在于行星表面的区域，离恒星太近会沸腾、太远会冻结。地球正位于太阳的宜居带内。寻找地外生命时，科学家常优先考察宜居带中的岩质行星。
The habitable zone is the region around a star where temperatures allow liquid water on a planet's surface, not so close it boils nor so far it freezes. Earth sits inside the Sun's habitable zone. In the search for life, scientists prioritize rocky planets in this zone.
难度 进阶 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
苏宜,《天文学新概论》第5版,科学出版社
Su Yi, Introduction to Astronomy, 5th ed., Science Press
独立核验依据 · Independent verification: 核验依据 2 ISBN 9787030620477（豆瓣书目条目: 天文学新概论）
#宜居带 #液态水 #生命
什么是气态巨行星？
What are gas giants?
气态巨行星以氢和氦等气体为主，没有明显的固态表面，内部在高压下气体可能变成液态金属氢。木星和土星是典型代表，体积质量都远大于地球。它们通常拥有强大的磁场和众多卫星。
Gas giants are dominated by hydrogen and helium with no clear solid surface; under high pressure the gas can become liquid metallic hydrogen inside. Jupiter and Saturn are classic examples, far larger and more massive than Earth. They usually have strong magnetic fields and many moons.
难度 进阶 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
苏宜,《天文学新概论》第5版,科学出版社
Su Yi, Introduction to Astronomy, 5th ed., Science Press
独立核验依据 · Independent verification: 核验依据 2 ISBN 9787030620477（豆瓣书目条目: 天文学新概论）
#气态巨行星 #木星 #土星
行星为什么有时会看起来『倒着走』？
Why do planets sometimes appear to move 'backward'?
从地球看，外行星在大部分时间顺行，但当地球从内侧追上并超过它时，相对视角变化使行星在星空背景上短暂向西逆行。这叫『行星逆行』，并非行星真的反向运动，而是地球更快的公转造成的视错觉。古代天文学家曾为此大伤脑筋。
From Earth, outer planets usually move eastward, but when Earth overtakes one on the inside, the changing viewpoint makes it briefly drift westward against the stars. This 'retrograde motion' is not real reversal but an illusion from Earth's faster orbit. It puzzled ancient astronomers greatly.
难度 进阶 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
苏宜,《天文学新概论》第5版,科学出版社
Su Yi, Introduction to Astronomy, 5th ed., Science Press
独立核验依据 · Independent verification: 核验依据 2 ISBN 9787030620477（豆瓣书目条目: 天文学新概论）
#行星 #逆行 #视运动
柯伊伯带和奥尔特云在太阳系结构中的角色有何不同？
How do the Kuiper Belt and the Oort Cloud differ in their roles within the solar system?
柯伊伯带是位于海王星轨道之外的盘状区域，包含冥王星等冰质天体，是短周期彗星的源地。奥尔特云则是包围太阳系的球壳状云团，距太阳可达数万天文单位，由长周期彗星组成。柯伊伯带由原位形成的残余星子构成，而奥尔特云天体被认为是被巨行星散射到远处的原始物质。
The Kuiper Belt is a disk-shaped region beyond Neptune holding icy bodies like Pluto and serving as the source of short-period comets. The Oort Cloud is a spherical shell tens of thousands of astronomical units away, populated by long-period comets. The Kuiper Belt consists of leftover planetesimals that formed in place, whereas Oort Cloud objects are thought to be primordial material scattered outward by the giant planets.
难度 进阶 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-11-04
来源 · Source
Jewitt 与 Luu《Discovery of the Kuiper Belt》（1993，Nature）；Oort《The structure of the cloud of comets》（1950，Bulletin of Astron. Institutes of the Netherlands）
Jewitt & Luu, Discovery of the Kuiper Belt (1993, Nature); Oort, The structure of the cloud of comets (1950, BAN)
独立核验依据 · Independent verification: 核验依据 1 Crossref DOI 10.1038/362730a0
#柯伊伯带 #奥尔特云 #彗星
木卫二的地下海洋假说建立在哪些观测证据之上？
On what observational evidence does the Europa subsurface-ocean hypothesis rest?
伽利略号探测到木卫二表面有冰壳的裂缝与稀少的撞击坑，并测得其磁场随木星磁场周期性变化，这是内部导电液体层的强信号。潮汐加热使冰壳之下保持液态，而表面的锰、镁等盐类暗示海水与岩石海底发生过反应。欧罗巴快船任务正进一步探测这一海洋的化学性质。
The Galileo mission saw a fractured, sparsely cratered ice shell on Europa and measured a magnetic field that varied with Jupiter's, a strong sign of an internal conducting fluid layer. Tidal heating keeps liquid water beneath the ice, and surface salts such as magnesium and manganese imply the ocean has reacted with a rocky seafloor. The Europa Clipper mission is now probing that ocean's chemistry in detail.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
苏宜,《天文学新概论》第5版,科学出版社
Su Yi, Introduction to Astronomy, 5th ed., Science Press
独立核验依据 · Independent verification: 核验依据 2 ISBN 9787030620477（豆瓣书目条目: 天文学新概论）
#木卫二 #地下海洋 #潮汐加热
除了土星，其他行星也有行星环吗？
Besides Saturn, do other planets have rings?
是的，木星、天王星和海王星也都拥有行星环，只是不如土星环明亮壮观。这些环大多由冰和岩石碎屑组成，可能是被潮汐力撕碎的卫星残骸。土星环之所以最显眼，主要是因为它更宽更亮且含冰更多。
Yes, Jupiter, Uranus and Neptune all have rings, though none are as bright and grand as Saturn's. They are mostly ice and rock debris, possibly remnants of moons torn apart by tides. Saturn's rings stand out because they are wider, brighter and icier.
难度 进阶 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
苏宜,《天文学新概论》第5版,科学出版社
Su Yi, Introduction to Astronomy, 5th ed., Science Press
独立核验依据 · Independent verification: 核验依据 2 ISBN 9787030620477（豆瓣书目条目: 天文学新概论）
#行星环 #土星 #天王星
金星为何会发生失控温室效应，与地球的分歧在哪里？
Why did Venus experience a runaway greenhouse effect, and where did it diverge from Earth?
金星比地球更靠近太阳，早期液态水蒸发后，水汽这种强温室气体使大气进一步升温。水汽上升至高层被太阳紫外光分解，氢逃逸到太空，二氧化碳则留在大气中积累到约90倍地球大气压。缺乏板块运动与液态海洋使碳无法被重新封存，温室效应彻底失控。
Venus sits closer to the Sun, and once its early liquid water evaporated, water vapor — a potent greenhouse gas — heated the atmosphere further. The vapor rose, was photodissociated by ultraviolet light, and its hydrogen escaped to space while carbon dioxide accumulated to about 90 times Earth's surface pressure. Without plate tectonics or oceans to reabsorb carbon, the greenhouse effect ran away completely.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
苏宜,《天文学新概论》第5版,科学出版社
Su Yi, Introduction to Astronomy, 5th ed., Science Press
独立核验依据 · Independent verification: 核验依据 2 ISBN 9787030620477（豆瓣书目条目: 天文学新概论）
#金星 #失控温室 #二氧化碳
火星大气是如何逐渐消失的，探测任务提供了什么证据？
How did the Martian atmosphere gradually disappear, and what evidence do missions provide?
火星引力较弱且缺乏全球磁场，太阳风粒子能直接剥蚀高层大气。NASA的MAVEN任务测量到火星仍在以每秒约100克的速度损失大气，主要是二氧化碳与水的离子被带电粒子带走。同位素比值显示轻的氩、氢流失更快，证实古代曾拥有更厚、更温暖的大气。
Mars has weak gravity and no global magnetic field, so the solar wind can strip its upper atmosphere directly. NASA's MAVEN mission measured the planet still losing about 100 grams of atmosphere per second, mainly ionized carbon dioxide and water carried off by charged particles. Isotopic ratios show lighter argon and hydrogen escaped faster, confirming an ancient thicker, warmer atmosphere.
难度 进阶 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
苏宜,《天文学新概论》第5版,科学出版社
Su Yi, Introduction to Astronomy, 5th ed., Science Press
独立核验依据 · Independent verification: 核验依据 2 ISBN 9787030620477（豆瓣书目条目: 天文学新概论）
#火星大气 #太阳风 #MAVEN
木星大红斑是什么，为什么它能在数百年里持续存在？
What is Jupiter's Great Red Spot, and why has it persisted for centuries?
大红斑是木星南半球一个比地球还大的反气旋风暴，由木星内部热量驱动而不是靠表面日照维持。木星没有固态表面的摩擦耗散，且周围急流不断向其输送角动量，使这个涡旋能长期自我维持。朱诺号测得它深度可达数百公里，是木星大气动力学结构的产物。
The Great Red Spot is an anticyclonic storm in Jupiter's southern hemisphere larger than Earth, driven by the planet's internal heat rather than surface sunlight. Jupiter lacks a solid surface to dissipate it through friction, and surrounding jets continually feed it angular momentum, letting the vortex sustain itself. Juno measurements show it extends hundreds of kilometers deep, a product of the planet's atmospheric dynamics.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
苏宜,《天文学新概论》第5版,科学出版社
Su Yi, Introduction to Astronomy, 5th ed., Science Press
独立核验依据 · Independent verification: 核验依据 2 ISBN 9787030620477（豆瓣书目条目: 天文学新概论）
#木星 #大红斑 #反气旋
土星环主要由什么物质构成，它们为何能长期保持结构分明？
What are Saturn's rings mainly made of, and why do they stay so sharply structured?
土星环几乎全部由水冰颗粒组成，大小从微米尘到数米巨块不等，环绕行星赤道面分布。土卫与环内粒子的密集轨道共振切割出卡西尼缝等清晰分界，并激发螺旋密度波。卡西尼号发现环物质持续受到微小陨石轰击而逐渐变暗，暗示它们相对年轻。
Saturn's rings are composed almost entirely of water-ice particles ranging from micrometer dust to meter-sized chunks, spread across the planet's equatorial plane. Dense orbital resonances with Saturn's moons carve sharp divisions like the Cassini Division and excite spiral density waves. Cassini found the ring material is steadily darkened by micrometeorite impacts, suggesting the rings are relatively young.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
苏宜,《天文学新概论》第5版,科学出版社
Su Yi, Introduction to Astronomy, 5th ed., Science Press
独立核验依据 · Independent verification: 核验依据 2 ISBN 9787030620477（豆瓣书目条目: 天文学新概论）
#土星环 #水冰颗粒 #轨道共振
木星和土星为什么那么巨大？
Why are Jupiter and Saturn so enormous?
木星和土星是气态巨行星，主要由氢和氦组成，不含固态表面。它们在太阳系形成早期位于较冷的外区，能够捕获大量气体，因此质量迅速增长。木星的质量是地球的300多倍，土星也超过地球95倍。
Jupiter and Saturn are gas giants made mainly of hydrogen and helium with no solid surface. In the cold outer solar system during formation they could capture huge amounts of gas, so their masses grew rapidly. Jupiter is more than 300 times Earth's mass, and Saturn over 95 times.
难度 入门 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-11-04
来源 · Source
Pollack 等 1996 年《Icarus》核吸积模型；NASA 关于气态巨行星形成
Pollack et al. (1996, Icarus) core-accretion model; NASA on gas-giant formation
独立核验依据 · Independent verification: 核验依据 1 Crossref DOI 10.1006/icar.1996.0190（复合著录按段核验：本标识只担保第一段 P
#木星 #土星 #气态巨行星