# Yvette Cendes on Reddit (u/Andromeda321)

Part of Scientists on Reddit, researched with Autumn (https://www.autumn.ai) from public sources. Updated 2026-11-07. Interactive version: https://www.autumn.ai/resources/scientists-on-reddit/yvette-cendes

Yvette Cendes: Radio astronomer, longtime "Astronomer here!" redditor.

- Reddit account: [u/Andromeda321](https://www.reddit.com/user/Andromeda321/) (Personal account)
- How we know it's theirs: [Named in her 2023 r/askscience AMA](https://www.reddit.com/r/askscience/comments/176w3y0/)
- Where they post, in the records we retrieved: r/AskReddit (9194), r/travel (2396), r/Andromeda321 (2032), r/IAmA (1512), r/space (642), r/Astronomy (545)
- Known activity in the posts we found: 2013 to 2026
- Wikidata: https://www.wikidata.org/entity/Q89275690

## Moments

### u/Andromeda321 in r/AskReddit, Nov 30, 2015 · Explains things

Replying to the post "What fact or statistic seems like obvious exaggeration, but isn't?".

> Radio astronomer here! You exert more energy when you unfold a single piece of paper than we have collected in *all* the radio waves we have *ever* collected from outer space.

(Excerpt.)
Full thread: https://www.reddit.com/r/AskReddit/comments/3uudrc/comment/cxhvnfh/ · 5,807 points as of Nov 7, 2026

### u/Andromeda321 in r/AskReddit, Dec 28, 2016 · Explains things

Replying to the post "What is surprisingly NOT scientifically proven?".

> Astronomer here!  Many of you have likely heard about [pulsars](https://en.wikipedia.org/wiki/Pulsar), which are neutron stars the size of a city that rotate as fast as thousands of times a second (and, at slowest, a few seconds per spin).  We know this because pulsars emit a beam of radiation in the radio spectrum, which we can see each time the pulsar spins (like a lighthouse beam).  We also can predict these beams so precisely they are more accurate than atomic clocks for timekeeping, and were used for [the first indirect proof of gravitational waves](https://en.wikipedia.org/wiki/PSR_B1257%2B12).
>
> So it sounds like we know a lot about pulsars, right?  Well get this- *no one has a clue what creates the emitted beam in the first place*.  We have known about these things since the 60s, and can do all these amazing experiments using them for timing, but what actually causes the emission?  No friggin' clue.  Neutron stars are just made of very exotic, very dense fundamental particles in ways that are impossible to recreate on Earth (a teaspoonful of the stuff would weigh about 10 million tons on Earth), so while there's been a lot of theoretical work on this problem no one knows as yet what causes the radio emission after half a century plus of research.

(Excerpt.)
Full thread: https://www.reddit.com/r/AskReddit/comments/5kq1p8/comment/dbpvi8p/ · 8,856 points as of Nov 7, 2026

### u/Andromeda321 in r/AskReddit, Sep 18, 2015 · Explains things

Replying to the post "What false facts are thought as real ones because of film industry?".

> Astronomer here!  There are a *lot* of bad things people think are true about astronomy because of movies, but to just highlight one: asteroid fields are completely different than what most people think they're like.  People tend to think of this crazy cramped field like in *Star Wars: The Empire Strikes Back* as the norm, but in actuality there is, on average, millions of kilometers between asteroids!
>
> Think of it this way: there are ~100,000 asteroids that are larger than a kilometer or so.  If we think of the asteroid belt between Mars and Jupiter, that still leaves you an average spacing of 5 million kilometers between asteroids.  In fact, there are so few that rather than having to worry about sending spacecraft through it due to too many, NASA had serious issues when *Galileo* was flying through on its way to Jupiter to ensure it passed close enough to asteroids to photograph them!

(Excerpt.)
Full thread: https://www.reddit.com/r/AskReddit/comments/3lf4rg/comment/cv5sku5/ · 4,773 points as of Nov 7, 2026

### u/Andromeda321 in r/AskReddit, Nov 7, 2016 · Personal story

Replying to the post "What's the smallest decision you made that had the biggest impact on your life?".

> From 6-12th grade (or age 11-18 for those not from the USA), I had a school bus ride home that lasted about an hour.  It sucked, and I spent the morning going in doing homework and the afternoon home reading.  One day, when I was in 8th grade, I ran through the library in panicked "class is out and I have just a few minutes to pick out a book else I'll be bored for an hour" mode, and happened to choose one on astronomy.  Still remember it exactly, it was called *From the Big Bang to Planet X* by Terence Dickinson and had the Andromeda Galaxy on the cover- a galaxy I've had an affinity for since now that I think about it. :)
>
> Anyway, by the end of that school bus ride I was already thinking about what kind of telescope I wanted to buy, and realizing with a shock that *any* 13 year old could technically grow up to be an astronomer, even if they lived in Pittsburgh.  And I wanted to be an astronomer ever since, and I am one now!  All because of that one book I happened to grab for my school bus ride home.

(Excerpt.)
Full thread: https://www.reddit.com/r/AskReddit/comments/5blita/comment/d9pgf1p/ · 22,339 points as of Nov 7, 2026