Interesting astronomy facts

[Mangosteen]

@KidScruffy

From wiki:

“The Earth’s distance from the Sun is about 400 times the Moon’s distance from the Earth. The Sun’s diameter is about 400 times the diameter of the Moon. Because these ratios are approximately the same, the sizes of the Sun and the Moon as seen from Earth appear to be approximately the same: about 0.5 degree of arc in angular measure.”

Coincidence? Or something more sinister…?

This also makes for one of the greatest astronomical phenomena there is: a total solar eclipse.

[mr.jp]

@mhendo

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.

I’m asking what bits you would find interesting, not about giving me a lecture in basic astronomy.

[Malacandra]

@Trunk

I still find it amazing that

1. orbits are elliptical

More or less, I guess this is because an elliptical orbit is self-correcting and therefore stable. If an orbiting object gets closer to its primary, it picks up speed. The speed takes it into a higher orbit, where it slows down and falls into a lower orbit. Rinse and repeat for stable equilibrium like a wobbling Weeble, because being displaced to either side creates a force pushing it back the way it came.

[mhendo]

@mr. jp

I’m asking what bits you would find interesting, not about giving me a lecture in basic astronomy.

Fair enough. I guess i just always assume that the experts in a field will have a pretty decent idea of what the most fascinating and compelling stories will be. For me, in a subject like astronomy, probably the most interesting thing would be something i’ve never heard before.

[JKellyMap]

@Musicat

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.

I used to think this, too, and indeed, some “constellations” are just random stars which, when viewed from some other angle, are actually far apart. However, many “constellations” really are loose groups of stars, often with a common (nebula?) origin. I’m pretty sure that Scorpio is a good example.

[Cervaise]

@FriarTed

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…

The sun is a mass of incandescent gas: a gigantic nuclear furnace.

Also, re Malacandra’s comment regarding the relative sizes of the Andromeda galaxy and our Moon, I’m not the only one who was deeply impressed by an actual image showing the comparison.

[Zebra]

If you dipped the planet Saturn in chocolate, it still wouldn’t taste very good.

[mr.jp]

Thanks SDMBers.

A lot of good suggestions!

@GrizzRich

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.

Yes, I already have this one. It’s a big hit.

[Tuckerfan]

@h.sapiens

Maybe you could do a talk about popular misconceptions about astronomy.

Phil Plait’s Bad Astronomy website is a good place to begin.

My thoughts exactly. One thing that you should, IMHO, try to do, is show how astronomy research impacts people’s daily lives. Most people don’t have an understanding that we learn about the Earth when we look at other planets. Even if the data isn’t directly applicable to our daily lives, the means by which it’s gained is. Our digital cameras owe their existence to the Hubble telescope, from what I understand.

[Hari_Seldon]

@Turek

The Andromeda galaxy is the only thing visible with the naked eye that’s NOT in the Milky Way galaxy.

I have read that the triangulum galaxy is also (barely) visible. On a clear night with no earth lights around, etc., etc.

To get back to the OP, I think I might talk about how interstellar distance scales are calibrated. From the speed of light and the distance to the sun using trigonomoetry to measure the change in the sun’s inclination at different latitudes) you have the width of the earth’s orbit and you can use slight changes from winter to summer to measure distance nearby stars and, eventually, any star with detectable proper motion, then the discover of cepheid and RR-Lyrae variables from which the distance to nearby galaxies can be found, which can be used to callibrate the red shift. Each measurement is used to callibrate the next. Perhaps, I am a geek, but I find this all fascinating.

[monstro]

Venus smells like burning, but Jupiter smells like butterscotch.

[Lust4Life]

@mr. jp

Im starting on a new job as a presenter at an observatory. I am to give a speech about astronomy to ordinary laymen. Do you guys have any suggestions for interesting, but simple, aspects of astronomy?

I have always been interested in astronomy and as a nipper joined the Royal Astronomical society.

I always enjoyed going to the London Planaterium next door to Madam Taussaeds waxworks.(I know that I spelled that wrong )
But the Planaterium started dumbing down the presentation I think to appeal to kids .
I stopped going and I think that kids who were genuinlly interested in astronomy stopped going and kids who weren’t actually interested in astronomy in the first place mostly did’nt bother going in the first place.

The London Planaterium has ceased trading,I hope you do not make the same mistakes.

[wolf_meister]

Yeah, like fachverwirrt and Wee Bairn, I also thought the traveling to the Sun “fact” seemed a little inaccurate and did some calculations.
Travelling at 100 kilometers per hour, you will reach the Sun in 170 years.

As a double check, that velocity is roughly 60 miles per hour and The Sun is 93,000,000 miles distant.
So 93,000,000 ÷ 60 mph = 1,550,000 hours = 64,583 days = 177 years.

That might be an interesting tidbit for your audience.

[Aquila_Be]

@Turek

The Andromeda galaxy is the only thing visible with the naked eye that’s NOT in the Milky Way galaxy.

According to this Link it could be as high as five galaxies outside the Milky Way.

There are four galaxies visible with the unaided eye from Earth, depending on where you live. In the Southern Hemisphere, the Large Magellanic Cloud and Small Magellanic Cloud can both be seen in fairly dark skies. In the Northern Hemisphere, the Great Andromeda Galaxy (also known as M31) is visible as a hazy smudge. The fourth galaxy, of course, is our own Milky Way, its bright arms spreading across the sky in a band of glory that can easily be seen in both Hemispheres, depending on the season.
All four of these galaxies are part of a group of about 20 galaxies, called the Local Group, that seem to be moving at about the same speed and direction through the universe.
A few other galaxies may be detectable with the naked eye, provided the observer’s eyesight is good enough and the skies are dark enough. Brighter galaxies such as M33 (in Triangulum), M83 (in Hydra), and even M81 (in Ursa Major) have been seen.