Look at your keyboard. Tucked above the number 8 is a symbol we see every day, yet rarely think about: the asterisk (*). We use it to correct a typo in a chat message, search for every file in a folder, or note a crucial exception at the bottom of a page. From masking a password field to bleeping out a curse word, this humble glyph is a silent workhorse of modern communication. But its story doesn’t begin with computers or typewriters. It begins over two millennia ago, with papyrus scrolls, brilliant scholars, and the greatest library of the ancient world.

A Star is Born in Alexandria

Our journey starts in the 3rd century BCE, in the legendary Library of Alexandria. This wasn’t just a repository of scrolls; it was a vibrant research center where the greatest minds of the Hellenistic world gathered to edit, critique, and preserve knowledge. One of the most prominent figures was a scholar and head librarian named Aristarchus of Samothrace.

Aristarchus and his colleagues faced a monumental task: creating definitive editions of classic texts, most notably Homer’s Iliad and Odyssey. Over centuries of manual copying, errors, spurious additions, and conflicting versions had crept into the manuscripts. To clean them up, they needed a system—a primitive form of version control.

They developed a set of critical signs to mark up the texts without altering the original. To mark a line they believed was superfluous or wrongly inserted, they used a symbol called the obelus (ὀβελός), which looked like a horizontal line or a division sign (– or ÷). But for lines that were correctly placed but appeared elsewhere in a duplicated form, or for lines that were genuine but perhaps misplaced, Aristarchus used a different symbol: a tiny, star-like burst. He called it the asteriskos (ἀστερίσκος), which is Greek for “little star”.

This little star was a scholar’s tool, a quiet note in the margin that said, “Pay attention here. Something is noteworthy”. It was the birth of editorial markup, a way to have a conversation with the text and with future readers across the centuries.

From Scroll to Press: A New Role in the Margins

The asterisk survived the fall of Rome and the so-called Dark Ages, dutifully copied by monks in medieval scriptoria. Its meaning, however, began to shift. The influential 7th-century scholar Isidore of Seville described the asterisk as a mark used to indicate something that had been omitted, which a scribe would then add in the margin. The obelus, in turn, was used to flag superfluous text to be removed. The core idea of “marking something special” remained, but the specifics evolved.

The real turning point for the asterisk came with Johannes Gutenberg’s invention of the printing press in the 15th century. Early printers, seeking to replicate the scholarly traditions of manuscripts, adopted these critical marks. The asterisk found a new, and now familiar, primary job: a reference mark.

When a printer needed to add a footnote, a correction, or a marginal comment, the asterisk was the perfect tool to create a link between the main text and the note. It was small, distinct, and didn’t interrupt the flow of reading too much. Soon, as books became more complex, a single mark wasn’t enough. Printers established a hierarchy of symbols for multiple footnotes on a single page, a sequence still recommended by some style guides today:

• Asterisk (*)
• Dagger (†)
• Double dagger (‡)
• Section sign (§)
• Pilcrow (¶)

The “little star” had graduated from a specialist’s tool to a standard feature of the printed page.

The Modern Explosion: A Star of Many Talents

If the printing press gave the asterisk a stable career, the digital age gave it a dozen more. Its simplicity and distinctiveness made it incredibly versatile in environments where complex formatting wasn’t possible. The asterisk became a symbol that could mean almost anything, depending on the context.

A Mark of Distinction (and Discretion) in Writing

In modern writing, the asterisk retains its classic role for footnotes but has also picked up new jobs. It’s the go-to symbol for self-censorship, standing in for letters in expletives (f***), a practice so common it has its own comic-strip name: a “grawlix”. A row of three asterisks (***) serves as a “dinkus”, a typographic divider that indicates a scene break in a story. And in the days of plain-text email and early internet forums, surrounding a word with asterisks (*like this*) was the universal sign for emphasis, a legacy that still influences Markdown syntax today.

The Linguist’s Secret Weapon

For students of language, the asterisk holds a particularly special meaning. In linguistics, placing an asterisk before a word or sentence signifies that it is ungrammatical or “ill-formed”. For example, *The cat sit on the mat immediately flags the sentence as violating English grammar rules.

Even more powerfully, in historical linguistics, the asterisk is used to mark reconstructed words from proto-languages—ancestral tongues that were never written down but whose forms can be inferred from their descendants. For instance, the Proto-Indo-European word for “water” is reconstructed as *wódr̥. That little star is a vital disclaimer, telling us, “This word is a scientific hypothesis; you won’t find it carved in stone”.

The Programmer’s Multi-Tool

Nowhere has the asterisk’s use exploded more than in computing. Its abstract nature makes it the ultimate utility player in the rigid syntax of programming languages.

• The Wildcard: In command lines and search queries, * is the universal wildcard, meaning “match any number of any characters”. A search for *.txt will find every single text file, regardless of its name.
• Multiplication: In nearly every programming language and spreadsheet program, * is the operator for multiplication (e.g., 4 * 5).
• Pointers: In languages like C and C++, the asterisk is used to declare a pointer, a complex but powerful variable that holds a memory address rather than a value.
• Comments & More: It’s used to denote comments (/* ... */ in CSS), import all modules from a library (from library import * in Python), and in regular expressions to match the preceding character zero or more times.

The Little Star That Could

From a simple mark correcting Homeric epics in Alexandria to a wildcard character shaping the digital world, the asterisk’s journey is a microcosm of our own communicative evolution. It has adapted, transformed, and multiplied its meaning across different eras and disciplines. It is a testament to how we imbue the simplest shapes with layers of complex meaning.

So the next time you type an asterisk to correct a message, multiply two numbers, or hide a password, take a moment to appreciate the “little star”. It’s more than just a symbol; it’s a direct link to the ancient scholars, medieval scribes, and pioneering printers who shaped the way we read and write today.