[Lex Computer & Tech Group/LCTG] Fwd: where is Webb

Wed Dec 29 06:42:10 PST 2021

I tried to send this to the group but it might have nly been sent to Mike A.

---------- Forwarded message ---------
From: L Wittig <9423lew at gmail.com>
Date: Wed, Dec 29, 2021 at 12:06 AM
Subject: Re: [Lex Computer & Tech Group/LCTG] where is Webb
To: Michael Alexander <mna.ma at yahoo.com>

I have to make a correction to my previous email. In reading the Orbit
section of the wikipedia article on the Webb the telescope will be put in a
halo orbit about L2. What I didn't realize in the size of the halo orbit.
It turns out that it has an average radius of about 500,000 mi, so it will
probably be in full sunshine most if not all of the time.  It will take
about 0.5 year to complete one orbit.
https://en.wikipedia.org/wiki/James_Webb_Space_Telescope#Orbit

On Tue, Dec 28, 2021 at 11:10 PM Michael Alexander <mna.ma at yahoo.com> wrote:

>
> Thanks, Larry.
>
>     – Mike Alexander
>
> On Tuesday, December 28, 2021, 9:52 PM, L Wittig <9423lew at gmail.com>
> wrote:
>
> Per wikipedia about L2: Sun–Earth L2 is a good spot for space-based
> observatories. Because an object around L2 will maintain the same
> relative position with respect to the Sun and Earth, shielding and
> calibration are much simpler. It is, however, slightly beyond the reach of
> Earth's umbra <https://en.wikipedia.org/wiki/Umbra,_penumbra_and_antumbra>
> ,[24] <https://en.wikipedia.org/wiki/Lagrange_point#cite_note-25> so
> solar radiation is not completely blocked at L2.
>
> Webb will see a ring of the sun like a full eclipse. It needs some sun for
> the solar panels to work.
> [image: annular-solar-eclipse.jpg]
>
> On Tue, Dec 28, 2021 at 6:16 PM George Gamota <ggamota at stma-llc.com>
> wrote:
>
> The location of the Webb is such that only some square feet need to be
> blocking the sun. Some geometry here helps.
>
>
>
> *From:* Carl Lazarus <carllazarus at comcast.net>
> *Sent:* Tuesday, December 28, 2021 5:14 PM
> *To:* 'George Gamota' <ggamota at stma-llc.com>; 'Stephen Quatrano' <
> stefanoq at gmail.com>; jjrudy1 at comcast.net
> *Cc:* 'Lex Computer Group' <lctg at lists.toku.us>
> *Subject:* RE: [Lex Computer & Tech Group/LCTG] where is Webb
>
>
>
> Is Earth’s shadow large enough to completely block the sun from the James
> Webb telescope?  I thought the telescope has an elaborate sun shield.
>
> -- Carl
>
>
>
> *From:* LCTG <lctg-bounces+carllazarus=comcast.net at lists.toku.us> *On
> Behalf Of *George Gamota
> *Sent:* Tuesday, December 28, 2021 3:41 PM
> *To:* 'Stephen Quatrano' <stefanoq at gmail.com>; jjrudy1 at comcast.net
> *Cc:* 'Lex Computer Group' <lctg at lists.toku.us>
> *Subject:* Re: [Lex Computer & Tech Group/LCTG] where is Webb
>
>
>
> Basically the Webb would be fried (electronics burned) if it ever sees the
> sun. So L2 places it in such a way that the Earth blocks the sun (an
> eclipse) all the time. Thus the Webb goes around the sun with Earth. Webb’s
> orbit then is one year just as the Earth.
>
> George.
>
>
>
> *From:* LCTG <lctg-bounces+ggamota=stma-llc.com at lists.toku.us> *On Behalf
> Of *Stephen Quatrano
> *Sent:* Tuesday, December 28, 2021 1:08 PM
> *To:* jjrudy1 at comcast.net
> *Cc:* Lex Computer Group <lctg at lists.toku.us>
> *Subject:* Re: [Lex Computer & Tech Group/LCTG] where is Webb
>
>
>
> Great graphics, John.  I didn’t understand L2 orbit so I Googled it:
>
>
>
> "The space telescope is destined to orbit a point in space known as
> Earth-sun Lagrange point 2 or L2, which is located nearly 1 million miles
> (1.5 million kilometers) away from Earth on the opposite side as the sun.
> The spacecraft covered the first 10% of that journey within 12 hours of
> launching.”
> https://www.space.com/james-webb-space-telescope-trajectory-burn
>
>
>
> "The James Webb Space Telescope will not orbit the Earth like Hubble but
> will in fact orbit the Sun. It will travel for approximately 30 days before
> reaching what is known as the second Lagrange point, or L2, 1 million miles
> away.” https://deepfieldfilm.com/discover/james-webbs-halo-orbit
>
>
>
> Looking at the second animation, I’m still not sure I understand it… but I
> keep trying.
>
>
>
> Regards,
>
>
>
> Stephen Quatrano
> CEO and Cofounder | Meema, Inc
> web: http://meemastories.com
> email: stephen.quatrano at meemastories.com
> <stephen.quatrano at meemastories.com>
> cell: +1 781-266-8799
> https://www.linkedin.com/in/quatrano/
>
> Board Member | The Right Question Institute
> http://www.rightquestion.org
>
> Lifelong Learner
> http://www.howdoweknow.info/p/home.html
> http://stefano.quatrano.us/
>
>
>
> On Dec 28, 2021, at 12:35 PM, <jjrudy1 at comcast.net> <jjrudy1 at comcast.net>
> wrote:
>
>
>
> This is a nice NASA site that shows its location in realtime
> https://www.jwst.nasa.gov/content/webbLaunch/whereIsWebb.html
>
>
>
> John Rudy
>
>
>
> 781-861-0402
>
> 781-718-8334  cell
>
> 13 Hawthorne Lane
>
> Bedford MA
>
> jjrudy1 at comcast.net
>
> <image001.png>
>
>
>
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