PARSECS, Light Years, or AU? (Astronomy)

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✵✵✵✵✵ Units of Distance in Astronomy
Light Years, Parsecs, AU (Astronomical Units) and kilometers
We’re familiar with kilometers (and miles) as measures of distance here on Earth. But when it comes time to measure distances of heavenly objects, it makes more sense to use the units AU, LY, and PC. That is, Astronomical Units, Light Years, and Parsecs. That’s because space is REALLY big!

Today we’ll examine these units that are most commonly used to measure distances in space, and when it makes more sense to use one rather than another. For instance, did you know that astronomical units (AU) are typically used for within our Solar System? But the distance to our nearest star, Proxima Centauri, is so huge that we really do need to jump up to using either Light Years or Parsecs. You'll even hear the terms megaparsec and gigaparsec!

✵✵✵✵✵ CHAPTERS
You can jump to chapters in the video here:
0:00 Introduction to AU Astronomical Units
0:33 AU Distances to planets in our Solar System
0:49 Using Light Years (LY)
1:05 LY in km
1:28 Proxima Centauri
1:37 Orion Nebula
1:52 Using Parsecs (PC)
1:57 PC in LY
2:07 Parsec name explanation
2:22 Parallax demonstration
3:23 What is an arc-second
4:15 d = 1/p
5:35 Challenge Question

You can check your work on the Challenge Question on our website:

✵✵✵✵✵ THANKS TO OUR SOCRATICA FRIENDS
This video was made possible by the generous support of our VIP Patrons on Patreon. What a blessing it is to have support from people who care about education! Let's take a moment to recognize these lovely souls:
Alvin Khaled, Carlos Araujo, Charles Southerland, Chris Kunstt, Christopher Kemsley, Colin Negrych, Deeptanshu Malik, Eric Eccleston, Israel Scott Grogin, Jeremy Shimanek, John Krawiec, Justin Fritz, Kavon Johnson, Kevin B, Marcos Silveira, MdeG, Michael Shebanow, Nunya Beezwax, Philip Rice, Rob Neal, Scott Dreblow, Tracy Karin Prell, and Umar Khan.

Many thanks go out to @LaunchPadAstronomy ! Liliana and Kimberly attended the annual Launchpad Astronomy Workshop for writers, led by astronomy professors Mike Brotherton and Christian Ready. Read more about our experience here:
Christian generously reviewed this script and offered advice. Be sure to check out his channel “Launchpad Astronomy” where your friendly neighborhood astronomer keeps you up to date on all the latest in the astro world.

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✵✵✵✵✵ CREDITS
Presented by Liliana De Castro
Written by Kimberly Hatch Harrison
Produced by Kimberly Hatch Harrison & Michael Harrison

Picture Credits
ESA/Hubble & NASA Proxima Centauri from Hubble Space Telescope

Orion Nebula - Spitzer Space Telescope

NGC 6717
Globular star cluster from Hubble Space Telescope
ESA/Hubble and NASA, A. Sarajedini

Meditations F8LKFUP3ZHZBPIZR
Keeping On SMGDBQIF83RWQWEQ

#Astronomy #LightYear #Parsec

[Socratica]

There's a Challenge Problem at the end so you can test your understanding. Give it a try!

[cerealport]

Great video. I'm interested in astronomy, but did not ever look up how a Parsec is defined, so, thanks for teaching me this!

[frankfreitasfreitas]

a suggestion for you to return with the series "back to school with the Socratic" in Portuguese. I love this series. just like all the others...
abraços do Brasil... 😄

[felipejin_]

gente, eu AMO essa atriz! ela continua incrível ❤️

[anusmita]

This channel is one of the best !! Really fabulous video..
I really love astronomy and science so much and my interest went more deep as I explore your channel..!

I never knew what is parsec but today I came across and learnt a new word from you!thanks a lot for this amazing videos..it's really helpful!!
Loved your channel, and subscribed too!!

[jdieioek]

One of the best channels! Thank you for the videos!

[hugomachadoart]

Thank you for making such great videos! This was really informative :D

[Insightfill]

I remember reading a lot of "Golden Age" science fiction and it really felt like parsec was going to be the unit to win!

[lilianemaciel]

I was already missing to see Lili performing. ❤

[AsiqueIkbalAnsari]

I need a teacher like you in my college !

[pramodpandey]

Thanks a lot for providing this awesome content! ✌️

[valerielhw]

For me, light time would be the easiest and most logical way to measure ALL distances in space, from galaxies that are billions of light years away, to the sun, which is around 8 light _minutes_ away.

[Krystina-UA]

Please more astro videos 🥰 love it so much.

[frankfreitasfreitas]

I speak fluent spanish and portuguese, but i speak very little english as i wish the socratic portuguese would come back liliana. ps: please come back. I really admire the work of the Socratic team.

[mostafaabbas]

I'm not that interested in this subject but the way you present it.. oh my 💕
Keep uploading please.

[hasanemon]

U makes hard things easy . Thank you mam

[SeptaShaenasSapphires]

Thanks for the videos! Do one on the Akkadese Maelstrom? 🤖

[batoolfareed]

Can you make a video about HX group, fuzzy set and hyper fuzzy, please ❤

[thegenxgamerguy]

Very nice video, because this explains the concept of parallax from the very, very beginning. This is what I like.

On a sidenote - if you want to write a sci fi story about a very uptight / correct / lawful scientist or something, he could say things like "we need to cross the distance of 4.503 parallax arc-seconds" or so. Would give this dude some colour, some old fashioned colour, if you know what I mean.

Some retrofuturistics.

[videoinformer]

30 AU to Neptune.
276, 264 AU to the nearest star.
The transition to using LY (4.37 LY to the nearest star) seems all the more necessary.
But we get back to using incomprehensible millions and even billions, even using LY or PC as our unit of distance, on the scale of the observable universe.
Even our "local group" of galaxies is 10, 000, 000 LY or 3, 000, 000 PC across, which is about 100 times the diameter of our own galaxy, the Milky Way.