The first letter of the Greek alphabet ande the brightest star in every constellation, this would make an interesting choice for a first daughter, though it does give off some spectral sci-fi reverberations--and references to the term "alpha male.". 

Alpha

A starry-eyed, intergalactic name, far rarer than Stella or Esther. It's attached both to a comic book character and to Princess Astra on "Doctor Who". 

Astra

Argon

Asteroid

Astroid

Even among the range of blue names on the current baby naming palette -- Blue itself, Azure, Cerulean, Teal, Aqua, Cyan, Indigo -- Cobalt remains the most unusual, not to mention the most masculine.

Cobalt

Even among the range of blue names on the current baby naming palette -- Blue itself, Azure, Cerulean, Teal, Aqua, Cyan, Indigo -- Cobalt remains the most unusual. 

Soaring astral name has a great gender-free feel. It also has a pleasing christmas connotation, courtesy of the reindeer listed in Rudolph the Red-Nosed Reindeer

Comet

Carbon

Copper

Cube

This simplified spelling is a bit too polyester, though this is also the authentic Slavic version of an Old Testament name that's being rediscovered.

Ester

Epsilon

Gamma

Helix

Jupiter's partner Juno has entered the mainstream, so it's possible that her divine mate could follow. But not necessarily for boys — Jupiter is currently mostly female in the US, thanks to its similarity to Juniper. Stars including Ed Sheeran and Ashley Tisdale recently welcomed daughters named Jupiter, which could shift the balance even more towards the girls.
 
The name of the supreme Roman deity and the largest planet has until recently had either too hippie or too grandiose a feel for most mortals, but with the rise of sound-alike Juniper and space names such as Orion and Mars, Jupiter may find new favor.
 
Short form Jupe is adorable.
 
More background on that deity: Jupiter was the king of the Roman gods, and god of the sky, the equivalent of Greek Zeus. His name may have originated as a title. It can be interpreted to mean "father of the sky" or "father of the gods" (dyew-peter > iou piter > iuppiter (the form of the name used in Latin) > Jupiter). With Juno and Minerva, he made the Capitoline triad, whose worship was at the very centre of Roman religion.

Jupiter

The name of the Roman goddess of the moon, Luna is derived straight from the Latin word for moon, luna. Luna may be the name most likely to surprise someone from an older generation by its Top 10 status in the US and its widespread international popularity.
Often ranked as Number 1 on Nameberry's internal charts, the strong but shimmery Luna is among the Top 100 names for baby girls in a wide range of countries around the world, from France to Italy to Germany, Scandinavia to Slovenia to Spain. It's simple, easy to spell and pronounce, and remarkably diverse.
 And it's also got deeper roots than you might imagine. It was somewhat popular in the US as a baby name around the turn of the 20th century, reaching a high of Number 403 way back in 1881.

Luna's popularity is undoubtedly influenced by the Harry Potter character Luna Lovegood and several high-profile celebrity babies, notably the oldest daughter of Chrissy Teigen and John Legend. 
 Along with its celebrity connections, Luna's popularity is partially driven by its standing as a mythological name. Luna’s divine complement is Sol, the god of the Sun. In Roman art, Luna is often depicted driving a chariot.
 
Luna makes another appearance as the endearing oddball Luna Lovegood in the Harry Potter series, who was central enough to the story to have Harry give his daughter Luna as a middle name, and as the True Blood teacher-shapeshifter character, Luna Garza. 
 
Along with Chrissy Teigen and John Legend, other celebrities who named their daughters Luna include Penelope Cruz and Javier Barden as well as Constance Marie. Joely Fisher and Ellen Pompeo have used it as a middle. Uma Thurman and Arpad Busson use Luna as the nickname they call daughter Rosalind Arusha Arkadina Altalune Florence.
 
Luna is also among the <a href="https://nameberry.com/popular-names/dogs">most popular dog names</a>.

Luna

Lampda

Lattice

This bold choice soared in popularity from 2008 to 2013, and now seems to have plateaued. But watch out—the character Major Major Major Major in the classic absurdist novel Catch-22 had a terrible time.

Major

The name of the Roman god of war began to sound less intimidating when Erykah Badu gave it to her daughter, and musicians Thomas and Bruno Mars (the latter born Peter Hernandez) have given it a modern edge. Mars actually could make a pleasant, planetary middle name for either sex.
In Roman mythology, Mars was the god of not just war, but also agriculture, and was more down-to-earth and less cold and ruthless than his Greek counterpart Ares. He was considered a father of Rome, as he was the father of mythical founder Romulus.

Mars

Adventurous parents are starting to look back to names of ancient gods like Mercury, Zeus, and Apollo. This one is also a planet and a metallic element, and has a friendly nickname, Merc. The Roman god Mercury, which derives from the Latin words for trade or wages, is the patron of tradesmen and travelers and the fastest-moving planet in the solar system. Mercury is the planet associated with the sign of Virgo, so this is one of the prime <a href="https://nameberry.com/blog/zodiac-baby-names-ideas-for-your-virgo-babe">names for Virgo babies</a>.

 Music lovers will also appreciate the connection to the legendary Freddie Mercury, born Farrokh Bulsara.

Mercury

The original oddball celebrity baby name, via Frank Zappa's daughter Moon Unit, who claims she's always liked it. 

Moon

Could be the next Nova, now that celestial baby names are in the ascendent.

Nebula

An obscure yet on-trend name with two wonderful meanings associated with it. Neoma is one of the freshest celestial girl names with moon-related meanings, rarer than Luna or Phoebe but with the same fluid sound.

 Despite being a hot name on Nameberry, Neoma is given to only a handful of baby girls per year in the US, although it enjoyed a little more popularity in the first four decades of the twentieth century, reaching Number 664 in 1907.

 Neoma's derivation is twofold. It is a Latinized variant of the Hebrew name Naomi, meaning "pleasantness". It also means "new moon" in Greek, from neo "new, young" plus mene "moon".

Neoma

Nova has the feel of both newness, from its meaning, and great energy as an astronomical term for a star that increases suddenly in brightness before fading. 
 Nova had some reasonable degree of popularity at the turn of the last century, only to disappear for more than 70 years before making a, well, astronomical comeback. Nova now ranks in the US Top 50 for baby girls and also entered the UK Top 100 in 2022. 
 Nova Pilbeam, the star of one of Hitchcock's early British films, had family ties to Nova Scotia. Other Nova ties: the long-running science TV show and the finest kind of lox. 
Given to more than 5000 girls in the US each year - and to a not insubstantial 240 boys - Nova is a current star that doesn't look as though it will be fading any time soon.

Nova

Neon

Omega is a perfect choice for a youngest child. 

Omega

Orion is a rising star, with both mythical and celestial overtones.
 The Greek mythological Orion was the legendary hunter who pursued the seven daughters of Atlas, was slain by the goddess Artemis, and then placed as one of the brightest constellations in the night sky by Zeus.
 Mark Twain had a brother named Orion, and Chris "Big" Noth picked the name for his son. It is also a Harry Potter name.
 Orion's Gaelic connection to O'Ryan/Ryan makes it familiar as well as unusual.

Orion

Radon

This number name first came to public attention when Erykah Badu and Andre 3000 chose if for their son, Seven Sirius Benjamin, born in 1997. Over a decade later, David and Victoria Beckham used it as their daughter's middle name, and now in these days of unisex word names, it's rising for both sexes. It's certainly one of the most name-like numbers: after all, it's only a letter away from Steven.

Seven

Most parents today would prefer the softer-sell Stella. But Star has symbolic power related to Christmas, so this could make one of the perfect <a href="https://nameberry.com/list/577/names-for-december-babies">names for December babies</a>.

Star

Stella is a name with star quality and sparkle, that manages to sound both ethereal and earthy. Celestial but not otherworldly, it lands somewhere between the popular Ella and bold Seraphina. 
 
The name Stella was derived from stella, the Latin word for “star”. It was coined by the poet, Sir Philip Sidney who used it in his 1590 sonnet collection, Astrophel and Stella, which translates literally to “the star lover and his star.” 
 
While Astrophel has remained obscure, Stella came into common usage in the 1800s. Inspired perhaps by its similarity to Ella and Esther, and by its association with the Virgin Mary, from her Catholic title, Stella Maris, it was popular in the early decades of the 20th century.
 
After fading in the 70s, Stella is now back and brighter than ever. Following on the heels of Gabriella and Isabella, it ranks in the US Top 50 and is given to almost 5000 babies each year. With equally astronomical Luna now making the Top 10, Stella might rise even higher.
 
Stella holds international appeal too and has taken shining spots on the charts in Switzerland, Sweden, Australia, Italy, and France. 
 
The name Stella was famously bellowed by Marlon Brando in Tennessee William’s A Streetcar Named Desire, and it has proved a popular choice among celebrities, including Matt Damon, Ellen Pompeo, Tori Spelling and Dean McDermott, and Gena Lee Nolin. 
 
Designer and animal rights activist Stella McCartney is another notable namesake, as is Stella Adler, an influential acting teacher. 
 
If Stella is shining for you but it’s not quite the brightest star on your list, then you could consider its variants, the literary Estella, or the French Estelle. Alternatively, you might like another starry name, such as Astraea, Seren, or Izara, or something just equally celestial, like Elara, Celia, or Celeste.

Stella

Sigma

Solar

Square

Theta is the name of the eighth letter of the ancient Greek alphabet, which is also the symbol of death. As such, it has rarely been used as a baby name.

Theta

Trojan

Another astral name, this one relating to one of the largest and brightest stars in the heavens, is popular in Scandinavia and Spain, where it ranks among the Top 50 <a href="https://nameberry.com/girls-names">girls' names</a>. Although still very rare in the US, we think it has serious potential to follow the likes of Luna and Lyra up the charts.

 In Spanish, the name means "meadow" and is taken from a title for the Virgin Mary (La Virgen de la Vega, The Virgin of the Meadow).

Vega

The name of a heavenly planet and the Roman goddess of beauty and love was an intimidating no-no until tennis champ Venus Williams put an athletic, modern spin on it. 
 
Associated with the Greek Aphrodite, in the Roman pantheon, Venus (whose name probably means "desire") was considered the mother of the Roman people and has always been a favorite subject of artists — most well-known being the prehistoric sculpture Venus of Willendorf, the ancient Venus de Milo and Botticelli's The Birth of Venus.

Venus

Vector

Virgo

Zenon is a relative of Zeno, which is a form of Zeus, used in both ancient Greece and modern Poland. With the new rise of all names mythological, this one may deserve a fresh look.

Zenon

Zero has been documented as a given name before, but it's largely familiar as a stage name (such as Zero Mostel, born Samuel Joel Mostel) and comic book and anime characters.

Zero

The sixth letter of the Greek alphabet, popularized by Welsh actress Catherine Zeta-Jones -- Zeta was her grandmother's first name.  Zeta can also refer to the letter Z, the last in the Roman alphabet, or be a spelling variation of Zita, a name with several possible origins and meanings.

Zeta

Extreme cool possibilities in either of these modern categories, like a postmodern Linc. 

Zinc

vintageluvs's list "Futuristic Science Names" of 50 great name ideas: Alpha - Zinc!