Super Moon! Largest in 20 years - Page 2

kennyc · 03-19-2011, 07:59 AM

15% is a lot! Probably is noticeable....sure was bright last night...

Edit: just saw this in the newspaper: 15% bigger, 30% brighter....

vivaldirules · 03-19-2011, 11:47 AM

Quote:

Originally Posted by vivaldirules

Okay, wikipedia says the average distance is 238,500 or so. So the full moon will be about 15% larger in diameter than average. I'm not sure that's enough for me to notice but I'll take a gander anyway. Thanks, Kenny.

Wait.

I took the square of the ratio of the distances. That's wrong. The diameter will be proportional to just the ratio of the distances. (duh! it's called "linear" perspective, doggie.) So the diameter will only be about 7% larger compared to when it is at its average distance. The apparent area will be proportional to the square of the ratio or 14% larger. The physical area will not be any larger but it will be closer so the moon should appear to be 14% brighter. Right? Or have I flunked high school math again?

Anyway, I'm pretty sure now that I won't notice the difference.

kennyc · 03-19-2011, 11:53 AM

Quote:

Originally Posted by vivaldirules

Wait.

I took the square of the ratio of the distances. That's wrong. The diameter will be proportional to just the ratio of the distances. (duh! it's called "linear" perspective, doggie.) So the diameter will only be about 7% larger compared to when it is at its average distance. The apparent area will be proportional to the square of the ratio or 14% larger. The physical area will not be any larger but it will be closer so the moon should appear to be 14% brighter. Right? Or have I flunked high school math again?

Anyway, I'm pretty sure now that I won't notice the difference.

I'm game for anything.

seagull · 03-19-2011, 01:45 PM

According to The Guardian there will be only a 0.3% difference. Not sure if being in the UK has anything to do with it though (can't see why).

HarryT · 03-19-2011, 05:08 PM

What they are saying is that it will only be 0.3% brighter than it is at the average perigee (which, of course, occurs once a month).

neilmarr · 03-19-2011, 05:12 PM

Certainly no difference I can spot here in the south of France. Hope the 'double moon' we're promised on March 31 is a tad more spectacular. Cheers. Neil

wannabee · 03-20-2011, 12:57 AM

Quote:

Originally Posted by neilmarr

Certainly no difference I can spot here in the south of France. Hope the 'double moon' we're promised on March 31 is a tad more spectacular. Cheers. Neil

Don't hold your breath Neil. As bright as Mars gets it's always a spec not a moon shape.

From my experience the moon really takes on it's EXTRA size when peeking over the horizen. I still remember watching such a full moon rise as a child and have been back to the same place on full moon evenings hoping to see it again. Alas that has not been the case.

Sydney has been overcast all weekend.

CHunter_Author · 03-20-2011, 01:22 AM

I went outside to see this moon and it wasn't all that. It is sizable, but nothing worth waiting 18 to 20 years for.

thrawn_aj · 03-20-2011, 01:31 AM

Supermoon, shmoopermoon? -> http://blogs.discovermagazine.com/ba...the-supermoon/

Neil, I'm afraid the two moons story has been floating around for a while now

- http://www.snopes.com/science/astronomy/brightmars.asp or http://www.hoax-slayer.com/mars-earth-close.html.

Here's an easy way to estimate out the relative sizes in the sky for a pair of astronomical objects (so, not birds or bees

):
D = actual diameter of object, L = distance of object from Earth

approximate angular size (as we see it) ~ D/L [think of the angle subtended by a very small arc of a very large circle].

size ratio of object 1 to 2 (as seen in our sky) = D1*L2/(D2*L1)

So, using the numbers (closest approach distance of Mars for example) in the usual form of this email, we see that Mars will look about 1.4% of the size of the moon. Impressive from an astronomical standpoint, but hardly twin moons eh?

nohmi2 · 03-20-2011, 02:27 AM

If we could have seen just an ordinary moon last night I would have been

happy.

Drove from Brisbane to Robina in the pelting rain.

Cheers

ardeegee · 03-20-2011, 02:42 AM

Quote:

Originally Posted by neilmarr

Certainly no difference I can spot here in the south of France. Hope the 'double moon' we're promised on March 31 is a tad more spectacular. Cheers. Neil

Oh, you weren't joking about that?

http://www.snopes.com/science/astronomy/brightmars.asp

GraceKrispy · 03-20-2011, 03:02 AM

I'm still waiting to see the moon! Darn Mountain to the East...

kennyc · 03-20-2011, 07:40 AM

Quote:

Originally Posted by CHunter_Author

I went outside to see this moon and it wasn't all that. It is sizable, but nothing worth waiting 18 to 20 years for.

kennyc · 03-20-2011, 01:40 PM

Not my photograph but one of last night's moon over Denver from a local news station:

http://www.9news.com/news/article/18...Saturday-Night

The Terminator · 03-20-2011, 07:57 PM

I saw it last night pretty cool

03-19-2011, 07:59 AM	#16
kennyc The Dank Side of the Moon Posts: 35,930 Karma: 119747553 Join Date: Sep 2009 Location: Denver, CO Device: Kindle2 & PW, Onyx Boox Go6	15% is a lot! Probably is noticeable....sure was bright last night... Edit: just saw this in the newspaper: 15% bigger, 30% brighter.... Last edited by kennyc; 03-19-2011 at 10:32 AM.

03-20-2011, 01:31 AM	#24
thrawn_aj quantum mechanic Posts: 705 Karma: 483827 Join Date: Aug 2010 Location: NorCal Device: Nook1, Samsung Transform, Nook2	Supermoon, shmoopermoon? -> http://blogs.discovermagazine.com/ba...the-supermoon/ Neil, I'm afraid the two moons story has been floating around for a while now - http://www.snopes.com/science/astronomy/brightmars.asp or http://www.hoax-slayer.com/mars-earth-close.html. Here's an easy way to estimate out the relative sizes in the sky for a pair of astronomical objects (so, not birds or bees ): D = actual diameter of object, L = distance of object from Earth approximate angular size (as we see it) ~ D/L [think of the angle subtended by a very small arc of a very large circle]. size ratio of object 1 to 2 (as seen in our sky) = D1L2/(D2L1) So, using the numbers (closest approach distance of Mars for example) in the usual form of this email, we see that Mars will look about 1.4% of the size of the moon. Impressive from an astronomical standpoint, but hardly twin moons eh? Last edited by thrawn_aj; 03-20-2011 at 01:38 AM.

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03-19-2011, 01:45 PM	#19
seagull Addict Posts: 247 Karma: 89950 Join Date: Dec 2009 Device: Amazon Kindle 2	According to The Guardian there will be only a 0.3% difference. Not sure if being in the UK has anything to do with it though (can't see why).

03-19-2011, 05:08 PM	#20
HarryT eBook Enthusiast Posts: 85,560 Karma: 93980341 Join Date: Nov 2006 Location: UK Device: Kindle Oasis 2, iPad Pro 10.5", iPhone 6	What they are saying is that it will only be 0.3% brighter than it is at the average perigee (which, of course, occurs once a month).

03-19-2011, 05:12 PM	#21
neilmarr neilmarr Posts: 7,215 Karma: 6000059 Join Date: Apr 2009 Location: Monaco-Menton, France Device: sony	Certainly no difference I can spot here in the south of France. Hope the 'double moon' we're promised on March 31 is a tad more spectacular. Cheers. Neil

03-20-2011, 01:22 AM	#23
CHunter_Author Zealot Posts: 118 Karma: 503896 Join Date: Jan 2011 Location: Bronx, NY Device: iPhone	I went outside to see this moon and it wasn't all that. It is sizable, but nothing worth waiting 18 to 20 years for.

03-20-2011, 02:27 AM	#25
nohmi2 Pensively observing. Posts: 1,758 Karma: 12675456 Join Date: Jun 2008 Device: Varied.	If we could have seen just an ordinary moon last night I would have been happy. Drove from Brisbane to Robina in the pelting rain. Cheers

03-20-2011, 03:02 AM	#27
GraceKrispy It's Dr. Penguin now! Posts: 3,909 Karma: 4705733 Join Date: Jan 2009 Location: (USA) Device: iPad mini, Samsung Note 3, Sony PRS-650 (rarely used now)	I'm still waiting to see the moon! Darn Mountain to the East...

03-20-2011, 01:40 PM	#29
kennyc The Dank Side of the Moon Posts: 35,930 Karma: 119747553 Join Date: Sep 2009 Location: Denver, CO Device: Kindle2 & PW, Onyx Boox Go6	Not my photograph but one of last night's moon over Denver from a local news station: http://www.9news.com/news/article/18...Saturday-Night

03-20-2011, 07:57 PM	#30
The Terminator Retired Posts: 2,552 Karma: 37638420 Join Date: Nov 2010 Location: Vancouver Island Canada Device: Kobo Touch, Optimus One (2.3), Nexus 7 (4.2)	I saw it last night pretty cool