Where is the Sun?

Where is the Sun right now?

Can’t see the Sun? Maybe there is something blocking it. Here is a list of 10 surprising things that can block the Sun.

IMAGE of floating/flying things overhead (in roughly size order) that can block all or part of the SUN: Flying animals (Bugs, Birds/Flying Mammals), Flying objects (Drones/Balloons/Airplanes/Helicopters/Rockets/Bombs/Blimps), Smoke/Clouds, Spacecraft (Satellites/Space Stations/UFOs), Asteroids, Moon, Mercury, Venus, Earth.
Wondering “Where is the Sun?” These are 10 things that block the Sun.

Where is the Sun during the day? On a clear day, this is a very simple question. The Sun is “up there” in the sky – it’s a big, bright, fiery ball and it’s generally a yellowish orange color. You just point to it – there it is, up in the sky, the Sun.

However, many things can block the Sun. Usually, it is clouds that block the Sun, but not always. Let’s take a tour of the astonishing number of things that can block the Sun.

A list of things on Earth and in space that can block the Sun

During a cloudy day you can’t always tell where the Sun is. The day goes by in a dull gray haze. In fact, some people who live in cloudy places like Seattle, Washington often wonder “Where is the Sun?” In fact, it’s cloudy in Seattle 308 out of 365 days of the year.

Sometimes other things besides clouds can block the Sun. These are mostly things that fly or float in air or space. There are small, flying animals like birds, bugs, and bats that can get in between us and the Sun.

Human-made objects like drones, balloons, airplanes, helicopters, rockets, bombs, and blimps can stop the light of the Sun from reaching us for a moment.

Smoke from a large fire, steam from a power plant, or ash clouds from a volcano will blot out the Sun for longer periods.

An asteroid can fly between the Earth and the Sun.

Most famously, the Moon can block the Sun in a total solar eclipse.

Image of the Total Eclipse August, 21, 2017 as seen from Folly Beach, SC
Image of the Total Eclipse August, 21, 2017 as seen from Folly Beach, SC – Image Credit Wyatt Cummings

The two inner planets – Mercury and Venus – will sometimes cross the face of the Sun (astronomers call this a “transit”). They seem very small against the disk of the Sun. Here is a side-by-side comparison of the two most recent transits (photo composite by Ender Gökçebay).

A comparison of the sizes of the planets Venus versus Mercury as they transit the Sun. Venus is a lot bigger, plus it is a lot closer to the Earth.
A composite of Venus transit and Mercury transit showing relative sizes as seen from Earth. Credit: Ender Gökçebay.
Venus transit, Mercury transit. These two inner planets sometimes cross the face of the Sun. Here we see the size comparison of the planetary disk.
Image credit Guiseppe Donatiello – public domain Wikipedia

Finally, we come to the largest Sun-blocker of all: the Earth. The Earth blocks the Sun every single day! In fact, it happens so often that long ago humans gave it a special name: when the Earth blocks the Sun, people call this “night.”

Sunset on Earth from space - where did the Sun go? It's behind the Earth right now so it's night.
The Earth blocks the Sun. It is night.

Where does the Sun go at night?

During the night, this question of “Where is the Sun?” gets a little bit more complicated. The Sun still exists – it doesn’t “go out” like a candle or a fire. The Sun is hidden from our view at night by a very large planet – the Earth. We cannot see through the Earth so it blocks the light from the Sun. But if somehow we could see through the Earth, we would be able to look down at the ground and see the Sun.

Bonus! A list of planets that will not ever block the Sun

There is only one planet that might completely block our view of the Sun and cause you to ask “Where is the Sun?” And there are only two other planets that throw shade on the Earth (Mercury and Venus) because they orbit closer to the Sun than we do.

Here is the list of planets that will never, ever block the Sun:

Mars, Jupiter, Saturn, Uranus, Neptune.

These planets never get between Earth and Sun. They are all further away from the Sun than us. Sometimes these planets go behind the Sun and the Sun blocks our view of them! Think about that for a minute…

Last words of advice about the question “Where is the Sun?”

Still looking for the Sun? It’s most likely clouds or night. But, maybe it’s one of these objects…

Are your eyelids in the way? Please make sure your eyes are open – eyelids can block the Sun for a long time – even during the day.

Put your hand down – a hand is an effective Sun-blocker.

Are you lying down on a picnic blanket? A foot held up in the air can block the Sun.

So can a person standing above you – ask your friend to move.

Track the Sun with a Sun Tracker

Liked this article? In the next installment of the “Where is the Sun?” series we look at some primitive and scientific tools that you can use to track the Sun.

Lights All Askew in the Heavens … But Nobody Need Worry

Lights all askew in the heavens…

Lights all askew... The hilarious headline provided by the New York Times after Einstein's relativity theory proved based on Arthur Eddington's eclipse observations in 1919. Lights all askew in the heavens. Men of science more or less agog over results of eclipse observations. Einstein theory triumphs. Stars not where they seemed of were calculated to be, but nobody need worry. A book for 12 wise men. No more in all the world could comprehend it, said Einstein when his daring publishers accepted it.
New York Times headline about Einstein’s theory of the curvature of space time.

This hilariously-headlined New York Times article describes the results of the observational experiment performed during the 1919 eclipse. It highlights that the expedition proved Einstein’s prediction. But the writer claims that only 12 men on Earth can really understand the result: that light’s path is curved by space time.

The delightful headline reads:

“Lights all askew in the heavens. Men of science more or less agog over results of eclipse observations. Einstein theory triumphs. Stars not where they seemed of were calculated to be, but nobody need worry. A book for 12 wise men. No more in all the world could comprehend it, said Einstein when his daring publishers accepted it.”

Einstein was a theoretical scientist. That means he dreamed up bold theories without direct experimental evidence. His science was one of the imagination. However, in order to succeed in science, a theory must be able to be proven false.

So, in 1919 an expedition went in search of observational evidence that would confirm or falsify the prediction of the “bending” of light in spacetime. The adventure was led by Arthur Eddington. They found proof of light’s bending rays by measuring the light of a star as it passed the mass of the Sun. The path of the light of a distant star bent in a curve around the edge of the Sun. This result did not falsify the theory and therefore indicated that Einstein’s theory was solid.

Can you understand space-time as Einstein did? Would you like to understand the ideas of light speed, and the observational reference frame that can speed or slow time?

Reference:

The New York Times scanned newspaper article from 1919.

https://timesmachine.nytimes.com/timesmachine/1919/11/10/118180487.pdf

 

Animal constellations in the night sky. How many are there?

There are 42 animal constellations in the night sky.

That is almost half of the official 88 constellations!

Here are the other types of constellations you will find in the celestial sphere. This is a fun activity for kids astronomy!

There are 42 animal constellations, 28 objects, 14 humans, 2 chimeras (a mix of human and animal), and 2 natural features (a river and a mesa).

Constellations are of many types. There are 42 animal constellations, 28 objects, 14 human constellations, 2 chimeras, and 2 natural features
88 official constellations broken down into 5 groups: 42 animals, 28 objects, 14 humans, 2 chimeras, and 2 natural features.

The 88 constellations listed by type:

Animal Apus Bird of Paradise
Aquila Eagle
Aries Ram
Camelopardus Giraffe
Cancer Crab
Canes Venatici Hunting dogs
Canis Major Big dog
Canis Minor Little dog
Capricornus Sea goat
Cetus Sea monster (whale)
Chamaeleon Chameleon
Columba Dove
Corvus Crow
Cygnus Swan
Delphinus Porpoise
Dorado Swordfish
Draco Dragon
Equuleus Little horse
Grus Crane
Hydra Sea serpent
Hydrus Water snake
Lacerta Lizard
Leo Lion
Leo Minor Little lion
Lepus Hare
Lupus Wolf
Lynx Lynx
Monoceros Unicorn
Musca Fly
Pavo Peacock
Pegasus Pegasus, the winged horse
Phoenix Phoenix
Pisces Fishes
Piscis Austrinis Southern fish
Scorpius Scorpion
Serpens Serpent
Taurus Bull
Tucana Toucan
Ursa Major Big bear
Ursa Minor Little bear
Volans Flying fish
Vulpecula Fox
Chimera Centaurus Centaur
Sagittarius Archer
Human Andromeda Princess of Ethiopia
Aquarius Water bearer
Auriga Charioteer
Bootes Herdsman
Cassiopeia Queen of Ethiopia
Cephus King of Ethiopia
Coma Berenices Berenice’s hair
Gemini Twins
Hercules Hercules, son of Zeus
Indus Indian
Ophiuchus Holder of serpent
Orion Orion, the hunter
Perseus
Perseus, hero who saved Andromeda
Virgo Virgin
Natural Feature Eridanus River
Mensa Table mountain
Object Antlia Air pump
Ara Altar
Caelum Graving tool
Carina Keel of Argonauts’ ship
Circinus Compasses
Corona Australis Southern crown
Corona Borealis Northern crown
Crater Cup
Crux Cross (southern)
Fornax Furnace
Horologium Clock
Libra Balance
Lyra Lyre or harp
Microscopium Microscope
Norma Carpenter’s Level
Octans Octant
Pictor Easel
Puppis Stern of the Argonauts’ ship
Pyxis (=Malus) Compass on the Argonauts’ ship
Reticulum Net
Sagitta Arrow
Sculptor Sculptor’s tools
Scutum Shield
Sextans Sextant
Telescopium Telescope
Triangulum Triangle
Triangulum Australe Southern triangle
Vela Sail of the Argonauts’ ship

 

Japanese robot will land on the asteroid Ryugu

The Hayabusa2 spacecraft visits the Ryugu asteroid

Update! June 24, 2018 – Haybusa2 has reached Ryuga. See this EarthSky.org article for more information.

I just received this wonderful message from a group of students in Japan (thanks to Patricia McGahan for providing the connection!) who are learning and teaching about the Japanese Hayabusa2 mission to the Ryugu asteroid.

(Welcome to Japanese language visitors and link to Japanese Wikipedia page.)

ようこそ!ここでは小惑星竜口へのはやぶさ2宇宙ミッションについて教えてくれる東京の高校生からの素敵なプロジェクトについてのあなたの情報です。

はやぶさ2ミッションのためのウィキペディアのページ。

Sugo-Haya2 Hayabusa2 JAXA mission English language version of the board game

These Japanese high school students created a board game (in Japanese and English) to teach people about an amazing Japanese spacecraft called Hayabusa2.

In June 2018, this Japanese spacecraft will meet up with the asteroid Ryugu, circle it for 18 months, then return to Earth with samples. In addition to observational instruments, the spacecraft has a small explosive material that will drop onto the asteroid! Talk about explosive science!

Explore the TTHS outreach website

The students would like you to explore their website and download the game which takes you through the stages of the mission.  The details and links are below.

Enjoy!

Click here to continue reading…

GPS uses Quasars

GPS uses Quasars to work

GPS uses quasars to get its own position
GPS satellite in low Earth orbit. Credit: NASA artist’s impression
The Global Positioning System (GPS) is precise.

That precision originates in a mind-blowing place!

GPS signals tell billions of people where they are each day.

GPS helps pilots land planes and captains steer ships.

GPS signals stamp locations onto millions of photos.

GPS gives you driving directions.

But, where does GPS get its own GPS?

The GPS for GPS

How does GPS know where a GPS satellite is?Click here to continue reading…

Blue Moon, Dark Moon, Nose Moon, Tail Moon

What is a Blue Moon?

The year 2018 is a Blue Moon bonanza! There was one in January and one on March 31st. The next one won’t arrive until October 2020. But, don’t worry… we’ve got 3 other types of moons lined up for you.

A blue moon tinted blue to make it look like the moon is actually blue. A blue moon means 2 full moons in a calendar month.
A Blue Moon. (This image was tinted to make it blue. No, a Blue Moon is not blue.)

The Basics

A Blue Moon happens when there is a Full Moon on the 1st* day of the month and a Full Moon on the last* day of the month. Two full moons in one month!

In other words, a Blue Moon is when there is a full moon twice in the same month. These two full moons always happen on the 1st or 2nd and the 30th and 31st of a month. “Blue Moon” is just a name for the second moon in that month – the moon does not turn the color blue.

Read on to learn about how the Blue Moon came to be and some suggestions for giving the other moon phases “Blue Moon” style names when they appear twice in a month. Suggestions are: Dark Moon, Nose Moon, and Tail Moon.Click here to continue reading…

Astronomy Koan

Astronomy Koan – Definition

A family views the visible orbit path of the earth.
A family views the visible orbit path of the earth.

An astronomy koan is a short, easy-to-memorize phrase that distills a key teaching about astronomy (especially physical astronomy).

The words are simple enough for a child to learn, but they carry complex insights about scientific observations.

The astronomy koan is a mnemonic that has layers of meaning or presents an ambiguous or challenging observation in a pithy phrase.

Try memorizing one of these – you can bring these with you everywhere.

Four Physical Astronomy Koans


That star rose earlier today.

The moon moves toward the dawn.

Night is where you are.

Same Sun all night. Dusk to the left, dawn to the right.


What do you think about these?

Do you know any astronomy koans?

Share your ideas in the comments section.

Merry-Go-Round Earth shows Seasonal Constellations

Welcome Starry Night event visitors! We built this fun, interactive model of the merry-go-round Earth on the evening of March 3rd, 2018 around a real campfire. Read on for the background and teaching method.

The Earth is like a Merry-Go-Round

Merry-Go-Round Earth model demonstrating how the seasonal constellations work
A Merry-Go-Round is a good model of daily Earth rotation.

The Earth is like a merry-go-round showing us seasonal constellations

That iconic childhood ride. Round and round each day we go, round and round each year we go, where we stop nobody knows! When we look out from the edge of the ride we can see the space beyond. Sometimes the Sun occupies that space, and sometimes that space is the night sky filled with stars.Click here to continue reading…

Stellarium – Find the Humanity Star

A new satellite called the Humanity Star looks like a disco ball

Update Apr. 1, 2018.

The Humanity Star is no longer an active satellite – it has fallen out of the sky: https://www.theverge.com/2018/3/22/17144208/rocket-lab-humanity-star-satellite-new-zealand-astronomy

However, even though the Humanity Star is now gone, this article still teaches you how to load satellites into Stellarium. So, read on for a quick tutorial on how to track any satellite in Stellarium.

Looking for information on how to track the Humanity Star any satellite location using Stellarium astronomy software?

Here is a quick tutorial on how to find the Humanity Star any satellite using Stellarium.

You can track the position of the Humanity Star with Stellarium
The Humanity Star satellite before launch – still on the Earth.

Rocket Lab founder and CEO Peter Beck announced that the company’s rocket had placed a special satellite in a 90 minute orbit around the Earth.

A lot of people want to see this new “star” in the sky. Stellarium can help you do that.

If you don’t have Stellarium, you can download a copy here. And I have a few tutorials that can help you get started with this amazing piece of software.Click here to continue reading…

Quiz – Can we see the Sun at midnight? Where is the Sun?

Can we see the Sun at midnight?

Yes. We can see the Sun at midnight. But, only if we are at one of the polar regions during the Summer season.

Image of the Sun's rays hitting the Earth. The Earth is tilted 23.4 degrees. Summer is when the northern hemisphere is titled toward the Sun. The summer Sun never sets - not even at midnight - if you are north of the Arctic Circle.
You can see the Sun at midnight! If you are at the North Pole in summer.

A quiz – seeing the Sun at midnight – don’t scroll til you try to answer!

When you see the Sun “rising” in the morning at dawn you are facing the east.

When you see the Sun “setting” at the end of the day you are facing the west.

Assuming you are not above the Arctic circle and not too close to the equator… if you could look right at the Sun (when the night is exactly half over) – by looking through the Earth – which cardinal direction would you be facing? East, West, North, or South?

Looking north or south to see the Sun at midnight?
A compass rose showing the cardinal directions.

Click here to continue reading…

“Star In a Star” Translated into 90 languages

Translation of Star In A Star Physical Astronomy articles

Would you like to learn how to say the word “star” in languages that are not your own? All of the articles about Physical Astronomy here at Star In A Star can be automatically translated. This amazing Google Translate widget lets you choose any language.
Google translate widget providing translation of Physical Astronomy teaching material to a global language audience
Google Translate widget can be used to translate these articles into any language.
Try it out! If you are on desktop … click the link at the top right to translate. If you are on mobile, click the translate widget at the bottom of the page.
For a bit of fun today… Here is a list of languages and the phrase “Star In A Star” in that language. I particularly like the languages where the word “star” changes slightly if it is inside another star (in Bosnian: zvezda u zvezdu). Also, I am fond of non-roman script languages – just for how beautiful they look ( this is Lao: ດາວໃນດາວ ).
Afrikaans: ster in ‘n ster
Arabic: نجمة في نجم
Azerbaijani: bir ulduzda ulduz
Belarusian: зорка ў зорцы
Bulgarian: звезда в звезда
Bengali: একটি তারকা তারকা
Bosnian: zvezda u zvezdu
Catalan: estrella en una estrella
Cebuano: bituon sa usa ka bituon
Czech: hvězdička ve hvězdě
Welsh: seren mewn seren
Danish: stjerne i en stjerne
German: star in a star
Greek: αστέρι σε ένα αστέρι
English: star in a star
Esperanto: star in a star
Spanish: estrella en una estrella
Estonian: star täht
Basque: izar bat izar batean
Persian: ستاره در یک ستاره
Finnish: tähti tähteä
French: étoile dans une étoile
Irish: réalta i réalta
Galician: estrela nunha estrela
Gujarati: સ્ટારમાં તારો
Hausa: star a star
Hindi: स्टार में स्टार
Hmong: star in a star
Croatian: zvijezda u zvijezdi
Haitian Creole: zetwal nan yon etwal
Hungarian: csillag egy csillagban
Armenian: աստղ աստղում
Indonesian: bintang di sebuah bintang
Igbo: kpakpando na kpakpando
Icelandic: stjörnu í stjörnu
Italian: stella in una stella
Hebrew: כוכב בכוכב
Japanese: 星の星
Javanese: bintang ing sawijining bintang
Georgian: ვარსკვლავი ვარსკვლავი
Kazakh: жұлдызға жұлдыз
Khmer: តារាក្នុងផ្កាយ
Kannada: ನಕ್ಷತ್ರದಲ್ಲಿನ ನಕ್ಷತ್ರ
Korean: 스타의 스타
Latin: star in a star
Lao: ດາວໃນດາວ
Lithuanian: žvaigždė žvaigždė
Latvian: zvaigzne zvaigznīte
Malagasy: kintana amina kintana
Maori: whetu i roto i te whetu
Macedonian: ѕвезда во ѕвезда
Malayalam: ഒരു നക്ഷത്രത്തിൽ നക്ഷത്രം
Mongolian: одтой од
Marathi: तारा तारा
Malay: bintang dalam bintang
Maltese: star fi stilla
Myanmar (Burmese): ကြယ်အတွက်ကြယ်ပွင့်
Nepali: स्टारमा तारा
Dutch: ster in een ster
Norwegian: stjerne i en stjerne
Chichewa: nyenyezi mu nyenyezi
Punjabi: ਸਟਾਰ ਵਿਚ ਸਟਾਰ
Polish: gwiazda w gwiazdce
Portuguese: estrela em uma estrela
Romanian: stea într-o stea
Russian: звезда в звезде
Sinhala: තරුවක තරුවක
Slovak: hviezdička v hviezde
Slovenian: zvezda v zvezdi
Somali: xiddigta xiddig
Albanian: yll në një yll
Serbian: звезда у звезду
Sesotho: naleli linaleli
Sundanese: béntang di béntang anu
Swedish: stjärnan i en stjärna
Swahili: nyota katika nyota
Tamil: நட்சத்திரத்தில் நட்சத்திரம்
Telugu: స్టార్ లో స్టార్
Tajik: ситораи дар ситора
Thai: ดาวในดาว
Filipino: bituin sa isang bituin
Turkish: bir yıldızla yıldız
Ukrainian: зірка у зірки
Urdu: ایک ستارہ میں ستارہ
Uzbek: yulduzli yulduz
Vietnamese: sao trong một ngôi sao
Yiddish: שטערן אין אַ שטערן
Yoruba: Star ni irawọ kan
Chinese: 明星在一个明星
Chinese (Simplified): 明星在一个明星
Chinese (Traditional): 明星在一個明星
Zulu: inkanyezi kwenkanyezi

Physical Astronomy – Definition of a New Way of Teaching

Definition of Physical Astronomy

Physical astronomy definition using Leonardo DaVinci's Vitruvian Man drawing surrounded by moon phase images
Vitruvian Man with Moon Phases

Physical Astronomy is a new way of teaching astronomy that emphasizes the human body and its relationship to other moving objects in space. The goal is to bring geometric and scientific awareness to a child’s everyday sky observations. Kids learn easily visible sky motions at a “kid’s eye level.”

The Sun does not move… we move

One of the first steps in Physical Astronomy is to forget you ever heard the words “Sunset” or “Sunrise.”  These words (while rife with history, beautiful in their own right, and descriptive) are scientifically wrong. These words obscure the truth of our trip around the Sun. We are on the Earth, the Earth is spinning; the Sun appears to be moving, but it is us moving. Click here to continue reading…

Moon Phase Emojis – A Review

Moon Emojis – and other space emojis

Emoji designers created a nice range of astronomy emojis and space emojis.  My favorite emojis are the Moon Phase Emojis. Space emojis to copy (these look different on each browser)

Here are the astronomy emojis and space emojis as real emojis that can be selected individually (or in groups) and copied. The moon emoji is my personal favorite.

Astronaut emojis

👩‍🚀 👨‍🚀

Earth globe emojis

🌎 🌍 🌏

Moon phases emojis in order from full moon to new moon to full moon

🌕 🌖 🌗 🌘 🌑 🌒 🌓 🌔 🌕

Moon emoji, Sun emoji, and Star emoji

🌚 🌝 🌞 🌛 🌜 🌙 💫 ⭐ 🌟 ✨

Explosion emoji, Comet emoji, Sun emoji, Rainbow emoji

💥 ☄ ☀ 🌈

Spaceship emoji, Satellite emoji

🚀 🛰

Map of earth emoji, moon viewing ceremony emoji, sunrise emoji, sunset emoji, shooting star emoji, city skyline with sun emoji, city skyline with moon emoji, and milky way emoji

🗺 🎑 🌅 🌄 🌠 🌇 🌃 🌌

Astronomy tools emoji, Telescope emoji

📡 🔭

Religions with moon and stars emoji

☪ ✡ 🔯

Abstract sun, earth, galaxy, star, and full moon emojis

🔅 🔆 🌐 🌀 *️⃣ 🎴

Horoscope emojis, Zodiac emojis

♈ ♉ ♊ ♋ ♌ ♍ ♎ ♏ ♐ ♑ ♒ ♓

Miscellaneous space symbol emojis

✳ ✴ ☾ 〰 ➰ ➿

Here is a screenshot of all of the moon emoji and space emojis as seen on Apple’s Mac “High Sierra” OS.

Bonus: this list shows the moon phase emojis in order – the correct order of the phases of the moon.

All of the astronomy and space themed emojis in one image
All of the astronomy and space themed emojis in one image

Emoji Variations

Did you know that Emojis look different depending on which type of device you are seeing them on?

Here is what the Full Moon Emoji looks like on Apple Macs

The Full Moon emoji as seen on Mac Computers - 3d, yellow, cratered, and glowing
The Full Moon emoji as seen on Mac Computers.

And here is what it looks like on Microsoft PCs

The Full Moon emoji as seen on Mac Computers - flat, orange, spotted, cartoon.
The Full Moon emoji as seen on Windows PCs.

References

Emojipedia has a catalog of all the variations of emojis including the Full Moon Emoji

 

 

See Mercury and Venus orbits during the day

Your hands and arms help you see the orbits of Mercury and Venus and the shape of solar system

Question: If you could see the orbit of Venus would it fill the whole sky?

The answer might surprise you!

You can use your hands and arms to see the size of the orbits of the solar system’s inner planets: Mercury and Venus.

Imagine (as pictured below) if the orbit of Mercury were visible as a red oval and the orbit of Venus were visible in green.

Use your hands and elbows to see Mercury and Venus orbits any time of day or night. The orbits of Mercury and Venus can be seen.
Two hand spans show Mercury’s orbit, elbows show Venus’s orbit.

Physical Astronomy – see Mercury and Venus orbits

Caution! Do not look directly at the Sun without proper solar safety glasses on.

Turn toward the Sun, hold your arms out straight, hands up in the air with fingers spread wide and thumbs touching. Your pinky fingers now span the width of the orbit of Mercury and your elbows span the width of the orbit of Venus.

Both of the entire orbits of Mercury and Venus orbits would be visible in the sky all at once – if they could be made visible during the day.

Click here to continue reading…

Shapes with Shadows – astrosketching Moon features with Alex Massey

Shapes with Shadows – what they can tell us

This the first of two special guest posts by Australian astrosketch artist Alexander Massey 

Live View Sketch of Moon craters Azrachel, Alphonsus, and Ptolemaeus by Alex Massey

Ptolemaeus, Alphonsus, and Arzachel… the names of three massive, interlocking craters on the Moon. These three craters tell the story of the ancient Moon’s creation and evolution. It’s a story of violent bombardments and oceans of lava. We can use light and shadows to reveal the shapes and deep history of these features.

Most people think of astronomy a science of light. But, light creates shadows when it hits things. Those features that lie in the shadows, the dark parts and seemingly just-in-the-way-of-the-light parts, are just as important as those that shine brightly. These dark shadows form most of the mass of all galaxies, house stellar nurseries, reveal old lava rivers on the Moon, and create curious plays of light and dark. These can play tricks on our eyes and make patterns appear.

Click here to continue reading…