Quadrantids象限儀座流星雨
80ZHR · 每時數41km/s · 公里／秒
A short, sharp peak in early January, named after an old constellation that is no longer used. Its parent may be a worn-out comet.
一月初短而集中的極大，名字來自一個已經不用的古星座。母天體可能是一顆耗盡的彗星。
Astronomy · Lesson 11 · 天文教育 第11課
Where Do Meteor Showers Come From?流星雨是怎麼來的？
A shooting star is a grain of comet dust burning up 100 kilometers overhead. Ride with Earth as it plows through a comet's trail on the same dates every year, and plan your night for the next shower over Changhua.
流星是一粒彗星碎屑，在 100 公里高空燒掉的光。跟著地球每年在同一天穿過彗星留下的碎屑帶，再規劃你看下一場流星雨的夜晚。
Big idea · 一句話看懂
Comets leave trails of dust along their orbits. Every year, Earth passes through the same trails on about the same dates, and the dust burns up in our air as a meteor shower.
彗星沿著軌道留下一條條碎屑帶。地球每年在差不多同一天穿過同一條碎屑帶，碎屑撞進大氣燒掉，就成了流星雨。
3D Model · 3D 模型
Earth Plows Through a Comet's Dust 地球穿過彗星的碎屑帶
Pick a shower. The colored loop is the orbit of its parent comet, and the glowing dots are the dust left along the way. Press Play: Earth travels around the Sun on real dates, and on about the same dates every year it reaches the gold ring and passes through the dust. Switch to Near Earth to watch the grains hit our air. On the right is the night of the peak over Changhua: every meteor seems to fly out of one point, the radiant.
選一個流星雨。彩色的圈是母彗星的軌道，發光的小點是它一路留下的碎屑。按「播放」：地球照真實日期繞太陽，每年差不多同一天走到金色圓圈，穿過碎屑帶。切換到「靠近地球」，看碎屑撞進大氣。右邊是極大那一夜的彰化天空：每顆流星都像從同一點射出來，那一點叫做輻射點。
Drag to turn · 拖曳旋轉 Scroll or pinch to zoom · 滾輪／雙指縮放
This 3D model needs WebGL, which this browser does not support. The sky chart and the list of upcoming showers still work.
這個瀏覽器不支援 WebGL，無法顯示 3D 模型；星圖與接下來的流星雨清單一樣能用。
- Colored dots: dust left along the parent's orbit (the trail is drawn wider than it really is)
彩色小點：沿著母天體軌道留下的碎屑（碎屑帶畫得比實際寬） - Gold ring: where Earth is every year at the shower's peak
金色圓圈：每年流星雨極大時，地球所在的位置 - Yellow lines near Earth: grains arriving from the direction of the radiant
地球旁的黃色短線：從輻射點方向迎面而來的碎屑 - Orbits and dates are real; the Sun and Earth are drawn much larger
軌道與日期是真的；太陽和地球畫得大很多
Orbits are to scale (1 AU = 10 units), and Earth moves on real dates. The Sun and Earth are enlarged, the dust trail is drawn wider than it is, and the far ends of long comet orbits are cut off at 6 AU. The sky chart shows the real radiant, stars, and Moon for the peak night.
軌道照比例（1 天文單位＝10 單位），地球照真實日期移動。太陽和地球放大了，碎屑帶也畫得比實際寬；長週期彗星的軌道外段在 6 天文單位處截掉。右邊的星圖用的是極大夜真實的輻射點、星星與月亮。
Meteor shower data: International Meteor Organization, Working List of Visual Meteor Showers (2027 Meteor Shower Calendar, ed. J. Rendtel). Parent orbits: NASA/JPL Small-Body Database. Earth's orbit: NASA/JPL approximate orbital elements. Stars: Yale Bright Star Catalogue, 5th ed. (public domain).
流星雨資料：國際流星組織（IMO）的目視流星雨工作清單（2027 年流星雨行事曆，Rendtel 編）。母天體軌道：NASA／JPL 小天體資料庫。地球軌道：NASA／JPL 近似軌道根數。星表：耶魯亮星星表第五版（公有領域）。
Reading · 英文閱讀
11
Unit 11: Where Do Meteor Showers Come From?
On a dark night, you may see a quick streak of light shoot across the sky. People call it a shooting star, but it is not a star at all. It is a meteor: a speck of space dust, often smaller than a grain of sand, slamming into Earth's air at up to 70 kilometers per second. The air in front of it gets so hot that it glows, about 100 kilometers above the ground, and the tiny grain burns up in less than a second.
黑暗的夜裡，你可能會看到一道光一閃劃過天空。大家叫它「流星」，英文說 shooting star（會飛的星），但它根本不是星星，而是一粒太空塵埃，常常比一粒沙還小，以每秒最快 70 公里的速度撞進地球的大氣。它前方的空氣被壓得非常熱而發光，高度大約在地面上 100 公里，這粒小小的碎屑不到一秒就燒光了。
Where does all that dust come from? Most of it comes from comets. A comet is a chunk of ice and rock a few kilometers across that travels around the Sun on a long, stretched orbit. When it comes close to the Sun, some of the ice turns to gas and blows dust out into space. Over hundreds and thousands of years, the dust spreads out along the comet's orbit like a trail of crumbs.
這麼多塵埃是從哪裡來的？大部分來自彗星。彗星是一團幾公里大的冰和岩石，沿著又長又扁的軌道繞太陽。它靠近太陽時，有些冰變成氣體，把塵埃吹到太空中。經過幾百、幾千年，這些塵埃沿著彗星的軌道散開，像一路撒下的麵包屑。
Earth's orbit crosses some of these trails. Every year, when Earth reaches the same point in its orbit, it plows through the same trail of dust, and we see a meteor shower. That is why each shower returns on about the same dates every year: the Perseids in August, the Orionids in October, and the Geminids in December. Halley's Comet gives us two showers, because Earth passes close to its orbit twice a year, in May and in October.
地球的軌道和其中一些碎屑帶交錯。每年地球走到軌道上同一個位置時，就穿過同一條碎屑帶，我們便看到流星雨。所以每個流星雨每年都在差不多同一天回來：英仙座流星雨在八月，獵戶座流星雨在十月，雙子座流星雨在十二月。哈雷彗星送給我們兩場流星雨，因為地球每年兩次經過它的軌道附近：五月一次，十月一次。
During a shower, trace the meteors backward, and they all seem to come from one spot in the sky, called the radiant. The grains are really moving side by side along parallel paths, but perspective makes them look as if they spread out from a single point, just as railroad tracks seem to meet in the distance. Each shower is named after the constellation where its radiant lies: the Perseids come from Perseus, and the Leonids from Leo. More meteors fall after midnight, when your side of Earth faces forward along its orbit, like the windshield of a car driving through rain.
流星雨的時候，把流星往回延長，它們好像都從天上同一點射出來，這一點叫做「輻射點」。其實碎屑是並排沿著平行的路線飛行，只是透視讓它們看起來從一點散開，就像鐵軌在遠方好像交會在一起。每個流星雨都以輻射點所在的星座命名：英仙座流星雨從英仙座來，獅子座流星雨從獅子座來。午夜以後流星比較多，因為那時你所在的這一面地球朝著軌道前進的方向，就像在雨中開車時的擋風玻璃。
People have watched meteor showers for thousands of years. In 687 BCE, the Chinese chronicle known as the Spring and Autumn Annals recorded that in the middle of the night, "stars fell like rain," one of the oldest records of a meteor shower anywhere. In November 1833, the Leonids filled the sky over North America with tens of thousands of meteors an hour. The American scientist Denison Olmsted noticed that they all came from one point in Leo and concluded that they must come from space. In 1866, the Italian astronomer Giovanni Schiaparelli showed that the Perseids follow the same path as a comet, Swift–Tuttle.
人類觀看流星雨已經好幾千年了。西元前 687 年，中國的《春秋》記載：「夜中，星隕如雨」，是世界上最古老的流星雨紀錄之一。1833 年 11 月，獅子座流星雨在北美洲的天空下，一小時有好幾萬顆流星。美國科學家奧姆斯特德注意到它們都從獅子座的同一點射出來，於是推論它們一定來自太空。1866 年，義大利天文學家斯基亞帕雷利證明，英仙座流星雨和一顆彗星「斯威夫特－塔特爾」走的是同一條路線。
You do not need a telescope to watch a meteor shower. Your eyes are the best tool, because they can take in the whole sky at once. Find a dark place away from city lights, lie back, and give your eyes about 20 minutes to get used to the dark. Be patient: meteors often come in bursts, with quiet minutes in between. A bright Moon washes out the fainter meteors, so check the list below to see when the next showers peak over Changhua and how bright the Moon will be.
看流星雨不需要望遠鏡。眼睛就是最好的工具，因為它能一次看到整片天空。找一個遠離城市燈光的暗處，躺下來，給眼睛大約 20 分鐘適應黑暗。要有耐心：流星常常一陣一陣地來，中間會安靜好幾分鐘。明亮的月光會蓋掉比較暗的流星，所以看看下面的清單，查查接下來的流星雨什麼時候在彰化達到極大，那時月亮有多亮。
Read aloud · 課文朗讀
Questions · 閱讀理解
What is a meteor?
A tiny piece of space dust, often smaller than a grain of sand, that burns up in Earth's air about 100 kilometers above the ground.
Why does each meteor shower come back on about the same dates every year?
Earth reaches the same point in its orbit on the same dates each year, so it passes through the same trail of comet dust.
Why do the meteors in a shower seem to come from one point in the sky?
The dust grains travel along parallel paths, and perspective makes parallel lines look as if they spread out from a single point, the radiant.
Words & Phrases · 生字及片語
meteor(n.)流星We made a wish when we saw a bright meteor.看到一顆明亮的流星時，我們許了願。comet(n.)彗星The comet had a long, glowing tail.那顆彗星拖著一條長長的、發光的尾巴。dust(n.)灰塵；塵埃There was a thick layer of dust on the old piano.舊鋼琴上積了厚厚一層灰塵。trail(n.)（留下的）痕跡；小路The muddy dog left a trail of footprints across the floor.那隻滿身泥巴的狗在地板上留下一路腳印。streak(v.)飛快地劃過A plane streaked across the sky.一架飛機飛快地劃過天空。peak(n.)最高點；高峰Traffic is at its peak at six in the evening.傍晚六點是交通的尖峰。burn up(phr. v.)燒光；燒毀The paper burned up in a few seconds.那張紙幾秒鐘就燒光了。patient(adj.)有耐心的Be patient; the fish will bite soon.要有耐心，魚很快就會上鉤。
Quick Check · 小測驗
1. A meteor is...
2. Why does a meteor shower come back on about the same dates every year?
3. Which comet gives us the Orionids in October?
4. When can you usually see the most meteors?
5. The radiant of a meteor shower is...
Eight Showers · 八大流星雨
A year of meteor showers 一年的流星雨
ZHR is the number of meteors one observer would see in an hour under a perfect dark sky with the radiant overhead; real counts are lower. Speed is how fast the grains hit our air.
ZHR（天頂每時出現率）是理想暗空、輻射點在頭頂時，一個人一小時能看到的流星數；實際看到的會比較少。速度是碎屑撞進大氣的速度。
Lyrids天琴座流星雨
18ZHR · 每時數49km/s · 公里／秒
Possibly the shower in the oldest record, from 687 BCE. Its comet comes back only once every 415 years.
可能就是西元前 687 年那筆最古老紀錄裡的流星雨。它的彗星每 415 年才回來一次。
Eta Aquariids寶瓶座η流星雨
50ZHR · 每時數66km/s · 公里／秒
Dust from Halley's Comet. Watch before dawn in early May; the radiant rises only a few hours before the Sun.
哈雷彗星的碎屑。五月初黎明前看；輻射點在日出前幾小時才升起。
Perseids英仙座流星雨
110ZHR · 每時數59km/s · 公里／秒
The favorite summer shower. Its comet is about 26 kilometers across, the largest object that passes near Earth again and again.
最受歡迎的夏季流星雨。它的彗星大約 26 公里寬，是一再接近地球的天體裡最大的。
Orionids獵戶座流星雨
20ZHR · 每時數66km/s · 公里／秒
More dust from Halley's Comet, hitting us almost head-on. Fast meteors like these often leave glowing trails.
又是哈雷彗星的碎屑，幾乎迎面撞來。這麼快的流星常會留下發光的餘跡。
Leonids獅子座流星雨
15ZHR · 每時數71km/s · 公里／秒
The fastest shower. Usually modest, but around the times its comet returns, about every 33 years, it has stormed, as in 1833, 1966, and 2001.
最快的流星雨。平常不多，但在它的彗星回歸前後（約每 33 年）曾經爆發成「流星暴」，例如 1833、1966、2001 年。
Geminids雙子座流星雨
150ZHR · 每時數35km/s · 公里／秒
Usually the richest shower of the year, and good for children: the radiant rises in the evening. Its parent is a rocky asteroid, not an icy comet.
通常是一年中最豐富的流星雨，也適合小朋友：輻射點傍晚就升起。母天體是岩石小行星，不是冰質彗星。
Ursids小熊座流星雨
10ZHR · 每時數33km/s · 公里／秒
A quiet shower just before Christmas. From Taiwan, the radiant near the Little Dipper never sets.
聖誕節前一個安靜的流星雨。在台灣，小北斗旁的輻射點整夜不會落下。
Plan Your Night · 觀測計畫
The Next Meteor Showers over Changhua 接下來彰化的流星雨
The next peak of each major shower, with the best time to look and how bright the Moon will be. Everything is calculated in your browser for today's date.
每個主要流星雨的下一次極大、最佳觀測時刻，以及那時月亮有多亮。全部在瀏覽器裡照今天的日期現算。
Calculating… · 計算中…
East and West · 東西方的星空
Stars That Fell Like Rain 星隕如雨
From ancient chronicles to modern science, meteor showers have puzzled and amazed people for thousands of years.
從古代史書到現代科學，流星雨讓人困惑、驚嘆了好幾千年。
687 BCE · 春秋
Stars Fell Like Rain夜中，星隕如雨
夏四月辛卯，夜，恆星不見。夜中，星隕如雨。——《春秋》莊公七年"In summer, in the fourth month, at night the usual stars could not be seen. In the middle of the night, stars fell like rain." (Spring and Autumn Annals)
This line is one of the oldest meteor shower records in the world. The date fits the Lyrids, which still return every April.
這一句是世界上最古老的流星雨紀錄之一。日期和每年四月回來的天琴座流星雨吻合。
彗 · Broom Stars
Comets in Chinese Records掃帚星
The Chinese character for comet means "broom," for its sweeping tail, and people called comets broom stars. Chinese astronomers recorded Halley's Comet on nearly every return since 240 BCE, long before anyone knew it was the same comet.
「彗」字的本義是掃帚，因為彗星的尾巴像在掃地，民間叫它掃帚星。從西元前 240 年起，中國天文官幾乎記錄了哈雷彗星的每一次回歸，那時還沒有人知道這些是同一顆彗星。
1833 · Olmsted
The Night the Stars Fell星星掉下來的那一夜
The Leonid storm of November 1833 frightened and amazed people across North America. Denison Olmsted collected reports and saw that every meteor came from one point in Leo, which moved with the stars. The meteors had to come from space, not from the air.
1833 年 11 月的獅子座流星暴，讓整個北美洲的人又害怕又驚奇。奧姆斯特德收集各地的目擊紀錄，發現每顆流星都從獅子座的同一點射出，而且那一點跟著星星一起移動——所以流星一定來自太空，而不是空氣裡。
1866 · Schiaparelli
Crumbs of a Comet彗星的碎屑
Giovanni Schiaparelli worked out the orbit of the Perseid grains and found it matched the comet Swift–Tuttle, seen in 1862. It was the first proof that meteor showers are made of comet dust.
斯基亞帕雷利算出英仙座流星的軌道，發現它和 1862 年出現的斯威夫特－塔特爾彗星一模一樣。這是「流星雨是彗星碎屑」的第一個證據。
Myth vs. Fact · 常見迷思
Four things people get wrong 四個常見的誤會
✗ Myth · 迷思Shooting stars are stars falling from the sky.流星是天上掉下來的星星。
✓ Fact · 事實A meteor is a grain of dust burning up about 100 kilometers overhead. Real stars are suns, light-years away, and they do not fall.流星是一粒塵埃，在頭頂大約 100 公里高的地方燒掉。真正的恆星是遠在好幾光年外的太陽，不會掉下來。
✗ Myth · 迷思The meteors come from the constellation they are named after.流星是從命名的那個星座來的。
✓ Fact · 事實The radiant is only the direction the grains come from, seen in perspective. The dust is inside our solar system, while the stars of Perseus are hundreds of light-years away.輻射點只是碎屑飛來的方向，加上透視效果。碎屑就在太陽系裡，而英仙座的星星遠在幾百光年外。
✗ Myth · 迷思You need a telescope to see a meteor shower.看流星雨要用望遠鏡。
✓ Fact · 事實A telescope shows only a tiny patch of sky, and meteors can appear anywhere. Your eyes, which see the whole sky, are the best tool.望遠鏡只看得到一小塊天空，流星卻可能出現在任何地方。能看見整片天空的眼睛才是最好的工具。
✗ Myth · 迷思Meteors from a shower often reach the ground.流星雨的流星常常會掉到地面上。
✓ Fact · 事實Shower grains are tiny, fragile bits of comet dust, and they burn up completely. The rare rocks that land, called meteorites, come from bigger chunks, mostly pieces of asteroids.流星雨的碎屑是又小又脆的彗星塵埃，會完全燒光。少數落到地面的石頭叫隕石，來自比較大的岩塊，大多是小行星的碎片。
Remember It · 記憶口訣
Catch a shooting star 一句話看懂流星雨
Comet crumbs彗星的碎屑
A meteor shower is Earth plowing through the crumbs a comet left behind.
流星雨，就是地球穿過彗星留下的碎屑帶。
Same trail, same date同一條碎屑帶，同一天
Earth crosses each trail at the same point in its orbit, so each shower comes back on about the same dates every year.
地球每年在軌道同一點穿過同一條碎屑帶，所以流星雨年年差不多同一天回來。
Trace it back往回連，找輻射點
If a meteor's path points back to the radiant, it belongs to the shower.
把流星的路徑往回延長，如果指向輻射點，它就屬於這場流星雨。
After midnight, more meteors後半夜比前半夜多
After midnight, your side of Earth faces forward, like a windshield in the rain.
午夜以後，你這一面的地球朝前方，就像雨中的擋風玻璃。
Classroom Activity 1 · 課堂活動一
Railroad Tracks in the Sky 天上的鐵軌
You need · 準備材料
- A ball of yarn and some tape一捲毛線和膠帶
- A long hallway or a playground一條長走廊或一片操場
- Five or six students to hold the yarn五、六位同學幫忙拉線
Steps · 步驟
- Stretch four or five pieces of yarn, each about 10 meters long, side by side and parallel, about 30 cm apart, at about head height.拉出四、五條約 10 公尺長的毛線，彼此平行、相隔約 30 公分，高度大約在頭部。
- One student stands at one end, just under the yarn, and looks along it toward the far end.請一位同學站在一端、線的正下方，沿著毛線往遠方看。
- Ask: do the lines look parallel? (No: they seem to spread out from a point at the far end.)問問看：這些線看起來平行嗎？（不平行：它們好像從遠方一點散開。）
- Explain: the meteors in a shower also travel side by side. The point they seem to come from is the radiant.說明：流星雨的碎屑也是並排飛行的；它們好像射出來的那一點，就是輻射點。
Teaching tip: then open the sky chart next to the 3D model and watch the meteors spread out from the radiant.
教學提示：接著打開 3D 模型旁的星圖，看流星從輻射點散開。
Classroom Activity 2 · 課堂活動二
Count Meteors Like a Scientist 像科學家一樣數流星
You need · 準備材料
- The list of upcoming showers on this page本頁「接下來的流星雨」清單
- A mat or reclining chair, warm clothes, and a red flashlight一張墊子或躺椅、保暖衣物、一支紅光手電筒
- A clipboard, a pencil, and a watch寫字板、鉛筆和手錶
Steps · 步驟
- Pick a night marked Good in the list. Go with an adult to a dark, safe place away from roads and lights.挑清單上標示「好」的夜晚，和大人一起到遠離道路和燈光的暗處。
- Lie back and let your eyes adjust for 20 minutes. Use only red light to read and write.躺下來，讓眼睛適應 20 分鐘；看紙寫字只用紅光。
- For one hour, write down the time of each meteor and whether its path points back to the radiant.觀察一個小時：記下每顆流星出現的時間，以及它的路徑是否指向輻射點。
- Add up your meteors for every 15 minutes, then compare with your classmates. Did more appear later in the night?每 15 分鐘加總一次，再和同學比較：越晚是不是越多？
Safety tip: always go with an adult, dress warmly, and never watch from a road or a rooftop.
安全提示：一定要有大人陪同，穿暖一點，不要在馬路上或屋頂上觀察。