November Quiz Released.

[OzEclipse]

The November quiz is open.

Warning: Fasten your seat belts, this is a tougher quiz.

click the photo before attempting the quiz:-

.

Play the quiz:-
app.php/quiz/play/9


@SparWeb @kt4hx @sdbodin @AntennaGuy @JayTee @Bigzmey @messier 111 @pixelsaurus @Gfamily @carastro @Juno16 @Graeme1858 @Juno16 @bobharmony @helicon @Gordon @SkyHiker @Michael131313 @JSBach1801 @astrorlk @Burrman@andrewsscope@jerrysykes

[pixelsaurus]

90%. Cheers.

[KathyNS]

A tough one! 60% for me, as a result of some lucky guesses. Thanks, Joe!

[helicon]

Wow. 20%.
Incredible! Obviously I have more to learn. I guessed on a few and got each of them wrong. I maybe should have spent longer than 4 minutes on it.

[Gfamily]

Is this a re-post, as the original seems to have been deleted?
Has the quiz changed at all?
For completeness I repeated (using the same wrong answers for honesty) to confirm my 70% score, but my time should be 3 minutes.

[Graeme1858]

60%

Should have got one more, if I had read it properly!

Good quiz quiz man! Thanks

Graeme

[kt4hx]

Well I messed that one up! I went back some questions to double check an answer then when I went forward I didn't notice that I had to re-answer the subsequent ones again as I worked back to the end. Those questions had no answers listed when the results page came up. So, I made a right mess of the whole thing! Good tough quiz Joe.

[Gordon]

Fun Quiz!!!

Only got 2 correct.

[Bigzmey]

Fun quiz, thanks Joe!

[OzEclipse]

Is this a re-post, as the original seems to have been deleted?
Has the quiz changed at all?
For completeness I repeated (using the same wrong answers for honesty) to confirm my 70% score, but my time should be 3 minutes.

Hi GFamily,
I’m not sure what you are referring to? I don’t have any control over how the quiz mechanics operate. I can edit the quiz but I would not delete and repost because that would change the url. 70% is a good score this time.
Joe

[OzEclipse]

Well I messed that one up! I went back some questions to double check an answer then when I went forward I didn't notice that I had to re-answer the subsequent ones again as I worked back to the end. Those questions had no answers listed when the results page came up. So, I made a right mess of the whole thing! Good tough quiz Joe.

There should be three columns. Question, your answer, correct answer. The photos have covered some of the questions and perhaps if you do this on a mobile phone or small tablet the photos might block more. I have no control over the appearance or not of the answers. Maybe a glitch?
Joe

[Gfamily]

Is this a re-post, as the original seems to have been deleted?
Has the quiz changed at all?
For completeness I repeated (using the same wrong answers for honesty) to confirm my 70% score, but my time should be 3 minutes.

Hi GFamily,
I’m not sure what you are referring to? I don’t have any control over how the quiz mechanics operate. I can edit the quiz but I would not delete and repost because that would change the url. 70% is a good score this time.
Joe

A mystery
I was sure I'd seen the November Quiz announcement, added my 'thanks' and replied to it not long after it went up. However, when I went back to the thread, my reply had disappeared, and there was no sign of the 'thanks'.
Do I have two records of having done the Quiz?

Never mind - enjoyed the Quiz, and am happy(ish) with my score.

[messier 111]

30 points , but I'm wasting time translating, I know I said it last time lol .
but I really love it, thank you for the dedication.

[sdbodin]

OK , 60%, just have one to quibble with.

Fun, BTW, somewhat hemispherically biased. I'll have to work on that.
Steve

[carastro]

30%. But it didn't count one l had corrected and would have got right.

Carole

[kt4hx]

Well I messed that one up! I went back some questions to double check an answer then when I went forward I didn't notice that I had to re-answer the subsequent ones again as I worked back to the end. Those questions had no answers listed when the results page came up. So, I made a right mess of the whole thing! Good tough quiz Joe.

There should be three columns. Question, your answer, correct answer. The photos have covered some of the questions and perhaps if you do this on a mobile phone or small tablet the photos might block more. I have no control over the appearance or not of the answers. Maybe a glitch?
Joe

Not a problem. In the future, if I go back to check an answer then move forward again, I will double check to make certain my previous answers are still there. I did go through it again later and had no issues. Didn't do particularly well, but I didn't go back the second time. So all is well.

[OzEclipse]

Well I messed that one up! I went back some questions to double check an answer then when I went forward I didn't notice that I had to re-answer the subsequent ones again as I worked back to the end. Those questions had no answers listed when the results page came up. So, I made a right mess of the whole thing! Good tough quiz Joe.

There should be three columns. Question, your answer, correct answer. The photos have covered some of the questions and perhaps if you do this on a mobile phone or small tablet the photos might block more. I have no control over the appearance or not of the answers. Maybe a glitch?
Joe

Not a problem. In the future, if I go back to check an answer then move forward again, I will double check to make certain my previous answers are still there. I did go through it again later and had no issues. Didn't do particularly well, but I didn't go back the second time. So all is well.

Hi Alan,

I tried this and finally see what you meant. I wasn't aware of this. Yes, if you use the back button to back up a few questions, you have to re-answer all the subsequent questions not just step forward. When I have performed test runs of the quiz prior to release, I have never reversed back multiple questions so wasn't aware of this.

Joe

[Juno16]

Hi Joe and thanks a bunch for taking the time to prepare this quiz.
I scored 40% and I’m thrilled with that!

[SparWeb]

Ouch, only 50%. Yes it was much harder this time.
Thank you, again.

[OzEclipse]

You can still attempt the quiz but now that I've published the answers below, scores won't count.

A round up of the questions from this months quiz. With some comments.
Question in black text.
Answer in green
My comments in blue.


2. The most common method used by amateur mirror makers for manually grinding the curve to make a telescope mirror sees the optician using two identically sized pieces of glass with wet abrasive in between. One is the mirror that becomes concave and the other is called the tool that becomes convex. The bottom piece is held in place on a rotating table top, the top piece of glass is pushed back and forth across the fixed surface.

While removing the glass to form the curve, which surface becomes the concave mirror, the piece on top or the piece underneath?

A: The mirror sits above with the fixed tool below on the bench

When making any mirror, the edges do the cutting. When pushing two equal size pieces of glass by hand, the downward pressure over the top moving piece allows the edge of the underside to preferentially remove material from the centre of the top piece causing it to become concave. When using a faceted sub-diameter tool, the edges of the small piece are always cutting material from the mirror and the only practical way is tool on top.

3. What is the surface temperature of our Sun?
A: 6,000 C / 10,800 F

The surface tempterature of the photoshere is around 6,000 C / 10,800 F although sunspots are somewhat cooler at 4,000 C / 7,200 F

4. Where would you find the Gegenshein?

A: At the antisolar point


Gegenschein is a faintly bright spot in the night sky centered opposite the position of the sun. The backscatter of sunlight by interplanetary dust causes this optical phenomenon, also called counterglow. I used the same answer set as I did for the Kordelewski Cloud question a few months ago because the Gegenshein question occurred to me when I was writing that question

5. On average, a total solar eclipse occurs somewhere on Earth once every:

A: 18 months

When statistically averaged over the whole Earth surface and over long periods of time, a total eclipse occurs on average once per 18 months. Over short periods, there is some variation. Two total eclipses can occur slightly less than 12 months apart as is the case with the April 20, 2023 total eclipse in Australia and the April 8, 2024 total eclipse in Mexico, US, and Canada and up to 2 years apart as was the case between the August 2017 solar eclipse in the US and the, July 2019 total eclipse in Chile and Argentina

6. If you put a piece of paper at the focus of a refracting telescope without an eyepiece, the image you will see focused will be:-

A: Inverted and reversed left to right.

Any refracting lens will both reverse and invert the projected image. It's all the same thing, after all, a lens is radially symmetrical. When we view the projected image, most commonly on the viewfinder screen of a camera, the pentaprism both reverses and inverts the image back to correct orientation. When projected directly onto a film negative, sensor, or projection screen, the image remains reversed and inverted

7. The Guinness World Record for most people simultaneously stargazing through telescopes across multiple venues in one country stands at more than 40000 people. Which country holds that record?
A: Australia

The record was first broken by the Australian National University in 2015. If you look up the site, it states, "The record for the most people stargazing at multiple venues is 7,960 participants and was organised by Mt. Stromlo Observatory, at the Australian National University (Australia) across 37 locations in Australia, on 21 August 2015." However the Guiness web site answer is now out of date. ANU broke it's own record 3 years later.

The Canberra Times ran this story in May 2018: https://www.canberratimes.com.au/story/ ... ld-record/
Here is the first paragraph in case you are blocked by a firewall.

The Australian National University has smashed its own Guinness World Record for the most people stargazing at multiple venues. More than 40,000 people across Australia turned their eyes to the sky at more than 280 events across Australia on Wednesday night, with more than 3500 of those at the university's Acton campus. That meant the university, in partnership with the ABC, beat its own record of 7960 people across 37 locations, set in August 2015.

As part of the successful record attempt, stargazers simultaneously observed the moon through a telescope for 10 minutes. Remote locations included Birdsville, Uluru, Alice Springs and Broome.

ANU is the university that employed me for 36 years and so unsurprisingly, I participated in both events.




8
Which galaxy, excluding the Milky Way, has the largest apparent diameter as observed from Earth?

A: The Large Magellanic Cloud

Many answered Andromeda. Andromeda has a naked eye apparent diameter of perhaps 0.5 - 2 degrees depending upon the individual's eyesight. The Large Magellanic Cloud has a naked eye diameter of 3 - 5 degrees from a very dark sky depending upon acuity of the individuals eyesight Photographically, Andromeda is 4-5 degrees while the Large Magellanic Cloud is almost 10 degrees.

Some complained that this was southern hemisphere favouritism. Perhaps a southern bias but balanced by numerous questions in other recent quizzes about star and constellation names in north polar constellations of Ursa Minor and Major and Camelopardalis among others; none of which are visible from mid-southern latitudes.


9 Many amateur astronomers roll their eyes at the terms “supermoon” and “micromoon” used extensively by the media to describe full moons that coincide with monthly lunar apogee and perigee. Approximately how much bigger is an apogee (super) Moon than a perigee (micro) Moon?

A: 14%

A close perigee is around 358000 km and a distant apogee around 410000 km making a difference of about 14%. You can search for extremes and go a little higher but not as high as 18% .

10 What's the temperature of the Sun's corona?
A: 1, 000, 000 Celsius / 1,800,000 Fahrenheit


This stumped many people and it is a somewhat surprising fact. The corona is heated by powerful concentrated magnetic energy guides that escape the sun through sunspots and heat the corona to temperatures much higher than the suns outer surface and more reflective of interior solar temperatures. Contrasting coronal to photosphere temperatures is a good point to raise if any of you are doing solar eclipse outreach.