From the southern hemisphere, the moon looks ‘upside down’ to us from the northern hemisphere. So the phases look reversed. That’s all it is.
NASA’s APOD (Astronomy Picture Of the Day) site is quite entertaining.
If you google “relative sizes of stars”, there are several sites that show pretty much the same series of photos of just how massive super-giant stars can be.
True. John Candy and Linda Hunt, for example, are two stars of vastly different sizes. 
I googled, and came up with this neat animation on star sizes:
http://infosthetics.com/archives/2006/12/relative_planet_size_movie.html
>Betelgeuse is not pronounced “beetle juice.”
It was when I got my degree in Astronomy 30 years ago. What happened?
A Tim Burton film, perhaps?
Does David Letterman know about this?
Ah ha, I see.
For my money I would like to hear about the strange effects that occur around black holes and at relevistic speeds. I don’t know if that is above a layman’s head or not, but I could listen to you talk about that crazy stuff all day. Or how about the weight of a teaspoon of neutron star on Earth. Or the fact that neutrinos are whizzing through us constantly - that’s kind of freaky.
I know this is not GQ, but if you meant that seriously, I’d sure like to see a cite.
Random stars as seen from the earth are so incredibly far apart even if in the same constellation (and in 3 dimensions, not just 2) that it seems unlikely that they would be that closely linked by gravity. And stars in constellations are truly randomly grouped even if they suggested outlines of animals to the imaginative ancients.
It may just be my personal bias as a scientist, but I think the most interesting “facts” about science are not what we know, but how we found out. Every scientific “fact” has a detective story attached to it. It can be ancient astronomy - e.g. how humans first found out the earth is a sphere, and how we measured its size. Or it can be more modern, e.g. how we found out what was creating the mysterious repetitive radio pulses (pulsars). But I wouldn’t try to make it a human-interest story. There’s enough mystery and intrigue in science without the mention of how other scientists didn’t believe the guy, how he slaved on a mountaintop for 20 years, etc.
I’ve been a fan of the Thousand Yard Model since I first read about it. I have yet to implement it myself, but if you do, let me know how it works out. (Note that the material on the linked page is copyrighted!)
It’s a scale model of the Solar System where the sizes of the objects and their distances are at the same scale. The sun is a basketball. The earth, 14 yards away, is a peppercorn. :eek: This really demonstrates the “space is big” idea from Hitchhiker’s Guide to the Galaxy.
The Andromeda galaxy is the only thing visible with the naked eye that’s NOT in the Milky Way galaxy.
Got a planetarium nearby? Try to sit in on a star talk or two, and check out the styles of more than one presenter if possible.
When I give star talks this time of year, I usually talk about the distances to the stars in the Summer Triangle. Vega: 25 light years away, actually appears brighter than Altair (16ly) just because Vega is just a bigger brighter star. Meanwhile Deneb is roughly the same apparent brightness as Altair, but is 3000 light years away. Deneb is a frickin’ huge intense star. The fact we can even see it from this distance is astounding.
Try to point the 'scope at Albireo to see the pretty blue-and-yellow double star.
Unless you’re in the southern hemisphere, where you can easily see the two Magellanic Clouds.
Even in the northern hemisphere, some people have seen M33 with the naked eye, under exceptionally good sky conditions.
Can i just ask the OP: how did you get this job?
It strikes me that someone who has been specifically hired to be a public presenter at an observatory should probably already have some idea of how to proceed, and should probably have a beetter sense of what might make an interesting astronomy speech than a bunch of random people on a message board.
I don’t mean to sound like a dick, and there is obviously nothing wrong with getting suggestions for what people might find interesting, but i’m rather surprised at your rather broad call for subject matter for a job you presumably already know something about.
The Batman villain Ra’s Al Ghul, played by Liam Neeson in “Batman Begins,” takes his nom-de-crime from the Arabic name for the eclipsing binary/variable star Algol in the constellation Perseus, where it represents the head of the Gorgon Medusa. See, you’ve got mythology, astronomy and Batman all in one!
Evidently, back in the mid 70’s, which was when I had my astronomy and physics courses–taught by the same instructor.
He was adamant that it rhymed with “metal jews.”
I’ve since done some Googling, and I see the most popular pronunciation is the same as the Michael Keaton character.
:: shrug ::
I hope I remember right that Betelgeuse is Orion’s right shoulder, or did that change, too? 
It still is. You’re not quite that old. 
I still find it amazing that
- orbits are elliptical
AND
- that planets “sweep out equal areas in equal time” to put it more colloquially.
That’s not immediately logical, but it’s somewhat easy to grasp with a diagram or two.
IOW, Kepler’s first couple of laws.
I do not vouch for the accuracy of this song, but I bet mr. jp would be a hit if he did a (corrected if need be) rendition of it…
“Just re-member that you’re standing on a planet that’s evolving and revolving at nine-hundred miles an hour.
That’s orbiting at nineteen miles a second, so it’s reckoned, a Sun that is the source of all our power.
The Sun and you and me and all the stars that we can see, are moving at a million miles a day,
In an outer-spiral arm at forty-thousand miles an hour, of the Galaxy we call the Milky Way…”
http://www.metrolyrics.com/galaxy-song-lyrics-monty-python.html
Which are, of course, a direct consequence of the inverse-square nature of gravity.