The Astrophysicist’s Alphabet

“When I was having that alphabet soup, I never thought that it would pay off.” –Vanna White

Ever want an A-to-Z illustrated alphabet of astrophysics? Turns out that — other than writing your own via Galaxy Zoo — it doesn’t yet exist. So I thought it would be delightful to make one for you… right now!

Image credit: Flickr user Image Editor / 11304375@N07.

A is for Aurora, polar lights fast and slow,
the Sun’s hot electrons make the atmosphere glow.

Image credit: Andrew Hamilton of JILA / Colorado,

B is for Black hole, a star’s collapsed heart,
once matter falls in, it will never depart.

Image credit: Comet West, retrieved from Cathy at

C is for Comet, with tails, dust, and ice,
a trip near the Sun makes them look very nice!

Image credit: STScI / NASA, ESA, R. Bouwens and G. Illingworth (UCSC).

D is for Doppler, turning galaxies red,
if you’re far, you’ll move fast, faster, fastest; you sped!

Image credit: Miloslav Druckmuller (Brno U. of Tech.), Peter Aniol, and Vojtech Rusin.

E is for Eclipse, where the Moon, Earth and Sun
cast light-blocking shadows, and cause tons of fun.

Image credit: Flickr user Image Editor / 11304375@N07.

F is for Fusion, that powers the stars,
nuclei join together, and the light is all ours!

Image credit: Dean Rowe of

G is for Galaxies, in clusters and groups,
with billions to find, no wonder we’re snoops!

Image credit: NASA / Space Shuttle, from 1997.

H is for Hubble, the telescope from space,
the sights it has seen help the whole human race.

Image credit: Robert Gendler of

I is for Ions, who make gas glow so bright,
when they find electrons, we see colorful light.

Image credit: X-ray: NASA/CXC/CfA/R.Kraft et al.; Submillimeter: MPIfR/ESO/APEX/A.Weiss et al.; Optical: ESO/WFI.

J is for Jets, from a galaxy’s core,
when it eats and spits matter, they’re active once more!

Image credit: © 2007 Dorling Kindersley.

K is for Kelvin, with Helmholtz, stars will cool,
so white dwarfs fade to black, it’s a great cosmic rule.

Image credit: Cleon Teunissen of

L is for Libration, which makes our Moon rock,
it’s a trick of the orbit; it’s tidally locked!

Image credit: Fred Bruenjes of Moonglow Observatory; 253 meteors from the 2007 Perseids.

M is for Meteors, which come in a shower,
at the right time of year, you’ll see hundreds an hour!

Image credit: NASA, ESA, HEIC, and The Hubble Heritage Team (STScI/AURA).

N is for Nebula, planetary, in this case,
when the Sun’s out of fuel, this is our fate in space.

Image credit: Axel Mellinger.

O is for Opaque, why the Milky Way’s dark,
without dust to block it, starlight would be stark!

Image credit: Optical: NASA/HST/ASU/J. Hester et al. X-Ray: NASA/CXC/ASU/J. Hester et al..

P is for Pulsar, a spinning neutron star,
as the orbits tick by, we know just when we are.

Image credit: K. Sharon (Tel Aviv U.) and E. Ofek (Caltech), ESA, NASA.

Q is for Quasars, great radio sources,
distant, active galaxies eating like horses!

Image credit: NASA / Cassini / the CICLOPS team.

R is for Rings, all gas giants possess them,
even one found in another sun’s system!

Image credit: ESA / Hubble & NASA.

S is for Spacetime, which curves due to matter,
this Universe-fabric, it bends but won’t shatter!

Image credit: High-Z Supernova Search Team, HST, NASA, of SN 1994D.

T is Type Ia, the best known supernova,
when White Dwarfs collapse, your distance? We’ll know ‘ya!

Image credit: NASA, ESA, G. Illingworth, D. Magee, and P. Oesch (University of California, Santa Cruz), R. Bouwens (Leiden University), and the HUDF09 Team; stitching of the HUDF and the XDF fields by me.

U is the Universe, which we’re still understanding,
with billions of galaxies, our spacetime’s expanding!

Image credit: Antoine Vergara Astrophotography.

V is for Virgo, our nearest great cluster,
with 1000+ galaxies, it’s a massive gut-buster!

Image credit: Nigel Sharp, Kitts Peak National Observatory/NOAO/AURA/NSF.

W is for wavelength, the energies of light,
it’s how we know what atoms are in stars just from sight!

Image credit: ESO, APEX (MPIfR/ESO/OSO), A. Weiss et al., NASA Spitzer Science Center.

X is for X-rays, which find starbursts (in red),
where the most massive galaxies form stars dead ahead.

Image credit: Larry McNish from RASC Calgary Centre.

Y is the Year, where we orbit our Sun,
each planet is different; the Earth is just one.

Image credit: The Milky Way through a Fisheye Lens, from Kitt Peak National Observatory.

Z is for Zenith, so gaze up towards the sky!
The Universe is here; let’s learn what, how and why.


  1. #1 Paulino
    October 8, 2012

    G- How come it is not for Gravity?
    What is the meaning of this insanity?

  2. #2 Violet
    October 8, 2012

    Ethan you are not far from reality ,keep up the good job and if you need more inspiration you may wish to visit me in a month time @ my website, just search for!!
    We will get there!!!
    We shall wash our eyes!!


  3. #3 Alexander Wolfe
    United States
    October 8, 2012

    I love that this starts off with a quote from Vanna White. Brilliant : )

  4. #4 OKThen
    Triassic period
    October 9, 2012

    So I just printed it out and will make it into a astronomy alphabet book for my 5 year old son.

    I’m serious. Have you ever watched the kids show Dinosaur Train? Well it’s great and my son knows a lot of the names of the dinosaurs from Archaeopteryx to Zigongosaurus.

    Yes I looked up those names here
    Seriously, I like dinosaurs but because of Dinosaur Train my son knows more correct scientific dinosaur names than I do.

    So maybe, he’ll know more about astronomy than me too. Which brings me to Ethan your new kid show Astronomy Travels that teaches kids all the correct astronomy names and theories at a kids level.

    Seriously Ethan here watch an episode of Dinosaur Train
    Oh well hopefully someone will put astronomy for kids in a cartoon

  5. #5 Bjoern
    October 9, 2012

    *claps hands*

    Really, really great! 🙂

  6. #6 Greg23
    October 9, 2012

    I do believe that’s Earth I see within Saturn’s rings (10:00 just inside the second outer ring).

  7. #7 nkthrasher
    October 9, 2012

    …So where does one order this in book form? Seriously.

  8. #8 Ethan
    October 9, 2012


    Put me in touch with a publisher, and I’ll try to get them to make it happen!

  9. #9 Waydude
    October 9, 2012

    Love it. Is there a poster?

  10. #10 Tihomir
    October 10, 2012

    Of all the web sites in the world, I’d expect at least yours would know that “B” stands for “Bang” or “Big Bang” :-))
    Nice poetry – especially the rhyme with “D” 😉
    Great blog as allways!
    Wish you all the best – Tihomir

  11. #11 Bernard
    October 10, 2012

    I hope this goes viral! Enjoyable, entrancing, inventive, and informative.

  12. #12 Rob Knop
    October 11, 2012

    Very nice. Of course, I can’t resist but nitpick. My cosmology bias, like yours, makes me like spacetime… but surely S should be for star?

  13. […] Here is an A-Z for astrophysicists! […]

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