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| | =Coincidence or Special Times?= | | =Coincidence or Special Times?= |
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| | <div class="post" id="post-190"> | | <div class="post" id="post-190"> |
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| | <p>[[File:DayNight.jpg|Day-Night-Howard]]<br /> | | <p>[[File:DayNight.jpg|Day-Night-Howard]]<br /> |
| | <em>image by [mailto:HowardEskildsen@msn.com Howard Eskildsen]</em></p> | | <em>image by [mailto:HowardEskildsen@msn.com Howard Eskildsen]</em></p> |
| − | <p>The Moon and the Sun are nearly the same angular diameter in the sky: 30 minutes of arc. Because of this, when the Moon passes fully in front of the Sun the latter’s direct radiation is blocked and the gaseous corona is momentarily visble writhing into space. From Earth this creates the awesome and rare spectacle of a solar eclipse. I have been fortunate to see two - one in southern Mexico and the other in northern Kenya, and wish that I were in the path of totality today. We are living in a coincidental time in Earth’s history when, as Howard’s unique composite of four images demonstrates, the Sun and Moon are the same size. Because Earth’s orbit is elliptical the Sun’s apparent size does vary a little (accounting for annular eclispes), but the Moon has appeared much larger in the past and will shrink in apparent size in the future. Tidal interaction with the Earth slows down our planet’s rotation and enlarges the Moon’s orbit. When the Moon first formed from the ring of debris orbiting Earth following the [http://www.lpod.org/?page_id=102 big splat] 4.5 billion years ago, it must have had a huge angular diameter. By some estimates the Moon may have been 22° in apparent size at 4 b.y. ago and was about half its present distance 3 b.y. ago when it was 4 times larger in apparent size. In early Earth history a telescope would hardly have been necessary to see the impact craters and mare lavas that were still forming. Today the Moon is receding at the measured rate of 3.82 cm/yr, and in some billions of years a month and a day will both be 47 current days long. Only one side of the Earth would see the Moon. Instead of flying half way around the world to see an eclipse, some people would have to go as far to see the Moon at all! And all solar eclipses will be annular and begin to look more like transits than eclipses. Astronomically, now is a good time to be alive.</p> | + | <!-- Removed reference to store page 2 --> |
| | <p>[mailto:tychocrater@yahoo.com Chuck Wood]</p> | | <p>[mailto:tychocrater@yahoo.com Chuck Wood]</p> |
| | <p><b>Technical Details:</b><br /> | | <p><b>Technical Details:</b><br /> |
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| | [http://skyandtelescope.com/observing/objects/eclipses/article_1701_1.asp The March 29, 2006 Solar Eclipse]<br /> | | [http://skyandtelescope.com/observing/objects/eclipses/article_1701_1.asp The March 29, 2006 Solar Eclipse]<br /> |
| | [http://www.astronomynotes.com/gravappl/s10.htm The Recession of the Moon]</p> | | [http://www.astronomynotes.com/gravappl/s10.htm The Recession of the Moon]</p> |
| − | <p><b>Yesterday's LPOD:</b> [[March 28, 2006|Rotating Gassendi]] </p> | + | <p><b>Yesterday's LPOD:</b> [[March 27, 2006|Amazing Grace]] </p> |
| − | <p><b>Tomorrow's LPOD:</b> [[March 30, 2006|No Crisis in Crisium]] </p>
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| − | <p align="center"><b>SUPPORT LPOD - VISIT A SPONSOR (CLICK AN AD BELOW)! </b><br />
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| − | <i>Now you can support LPOD when you buy any book from Amazon thru [http://www.lpod.org/?page_id=102 LPOD!]</i></p>
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| − | <p><b>Yesterday's LPOD:</b> [[March 28, 2006|Rotating Gassendi]] </p>
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| | <p><b>Tomorrow's LPOD:</b> [[March 30, 2006|No Crisis in Crisium]] </p> | | <p><b>Tomorrow's LPOD:</b> [[March 30, 2006|No Crisis in Crisium]] </p> |
| | </div> | | </div> |
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| + | </div> |
| − | ===COMMENTS?===
| + | <p> </p> |
| − | Register, and click on the <b>Discussion</b> tab at the top of the page.
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| − | <hr> | + | <p> </p> |
| − | <!-- | + | <!-- End of content --> |
| − | You can support LPOD when you buy any book from Amazon thru [[Support_ LPOD|LPOD]]!
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| − | Contributions to http://www2.lpod.org/ are licensed under a Creative Commons Attribution No-Derivative-Works Non-Commercial 3.0 License. [http://www.creativecommons.org/licenses/by-nc-nd/3.0 http://www.wikispaces.com/i/creativecommons/by-nc-nd_3.0_80x15.png]<br>
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