asteroid 2012 DA14 next week

N_Cook

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Feb 7, 2013, 4:09:42 AM2/7/13

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If I go out on Valentine's day next week with binoculars and clear sky at
the Plough and manage to see this object going zenithwards across the handle
of the pan-handle 21:00 to 22:00 or so, will it be varying brightness from
tumbling. ?
If it is tumbling before near earth encounter would that gravitational
encounter stop the the tumbling of an asymetric object?

Sjouke Burry

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Feb 7, 2013, 3:15:55 PM2/7/13

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"N_Cook" <div...@tcp.co.uk> wrote in news:kevqpl$11g$1...@dont-email.me:

Yes.
No.

N_Cook

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Feb 8, 2013, 4:20:58 AM2/8/13

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Sjouke Burry <s@b> wrote in message
news:XnsA160D852F4DEDsj...@213.75.12.10...

Would the brightness variability be perceivable by simple looking through
binoculars (if seen at all) and over what sort of periodicity?

N_Cook

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Feb 8, 2013, 7:13:04 AM2/8/13

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For the UK it is the 15 Feb

Sjouke Burry

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Feb 8, 2013, 2:20:57 PM2/8/13

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"N_Cook" <div...@tcp.co.uk> wrote in news:kf2g2g$5ms$1...@dont-email.me:

Depends on how fast it is tumbling, and how irregular the surface is.

Dr J R Stockton

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Feb 12, 2013, 5:42:48 PM2/12/13

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In uk.sci.astronomy message <XnsA160D852F4DEDsj...@213.75
.12.10>, Thu, 7 Feb 2013 20:15:55, Sjouke Burry <s@b.?.invalid> posted:

I would expect that a non-tumbling asymmetric asteroid approaching from
infinity would be tumbling after the encounter. Gravitational motion is
time-reversal symmetric. Therefore an asteroid approaching from
infinity with just the right tumble would not be tumbling when it
finally reached infinity again. So only rather probably No.

IIRC : Consider not Niven's "Neutron Star" itself, but comments made
after its publication, such as in
<http://en.wikipedia.org/wiki/Neutron_Star_%28short_story%29#Notes> blob
2.

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(c) John Stockton, nr London, UK. Mail via homepage. Turnpike v6.05 MIME.
Web <http://www.merlyn.demon.co.uk/> - FAQqish topics, acronyms and links;
Astro stuff via astron-1.htm, gravity0.htm ; quotings.htm, pascal.htm, etc.
No Encoding. Quotes before replies. Snip well. Write clearly. Don't Mail News.

N_Cook

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Feb 13, 2013, 5:11:56 AM2/13/13

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Dr J R Stockton <repl...@merlyn.demon.co.uk.invalid> wrote in message
news:TeACMKNo...@invalid.uk.co.demon.merlyn.invalid...

I'll try looking ESE about 20:00, when brightest, but whether I can make out
Denebola is another matter, I hope these path charts are still valid
http://www.britastro.org/~rmiles/Images/2012DA14_UKchart_1950-2100UT.png
Path 20:00 to 21:00

http://www.britastro.org/~rmiles/Images/2012DA14_UKchart_2100-0100UT.png
Path 21:00 to 01:00

N_Cook

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Feb 16, 2013, 5:58:34 AM2/16/13

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Too much mist at horizon level for me to see with binos at the Leo level ,
and returned to it for the Plough crossing but had clouded over by then, so
did not see it.
I wonder what traumatised state that Russian was who took that image of that
meteor/ite coming straight for him, an amazing piece of phone-cam imagery