Thursday, January 28, 2010

Tu B'Shvat 2010: Harmony on earth, and Mars above

See full size image

Tu B'Shvat, the festival of trees here in Israel, is a holiday that evokes the intrinsic harmony of nature, the existential beauty of God's creations here on earth and the myriad benefits we humans derive therefrom.  With such amity on the calendar, we may read with shock about what is happening at the same time in the heavenly sphere: MARS IN OPPOSITION!

 Mars by  Bill Flanagan.
Mars on Jan. 22, 2010Mars's name in English is for the Roman god of war, but its name in Hebrew, Maadim, denotes its pretty red (adom) hue rather than any military associations.  And "opposition" with reference to celestial bodies simply means that the planet is at its closest and brightest for this particular orbit.  So harmony reigns in the skies as well as on earth on Tu B'Shvat, and we can all relax.

Mars, reports the Astronomer, can be easily seen in the early evening as it rises in the east (OPPOSITE the setting sun)(sorry, Tom, but some of us are confused by these things) and is up all night.  Those sky gazers who can find Orion (look for the three bright stars of his belt) and his loyal dog, Sirius (the brightest star in the sky) will see Mars to the left of Sirius--about the same brightness ("apparent magnitude") but with its characteristic reddish-orange color.

Sky gazers for whom Orion remains elusive will have extra help locating Mars this weekend because the Moon will be shining in the same part of the sky both Friday and Saturday night.  On Friday, the Moon will be slightly above and to the right of Mars; on Saturday night, the Moon will be slightly below and to the right of Mars.

Sky and Telescope has a lovely, not-too-complicated guide for helping to locate these things.  The Moon in the picture is correct for the US.  In Israel the Moon will be a bit lower each night as described above.

Happy viewing!
The Astronomer says: Keep looking up!

Monday, January 18, 2010

Solar Eclipse that was

Solar Eclipse in Efrat!

 הַשָּׁמַיִם מְסַפְּרִים כְּבוֹד-אֵל  וּמַעֲשֵׂה יָדָיו מַגִּיד הָרָקִיעַ
Psalm 19:2 The heavens declare the glory of God, and the firmament shows His handiwork

On Friday, the Astronomer got up early.  He'd spent a restless night, tossing and turning and worrying lest the clouds block the view and spoil a rare chance to show off one of the more spectacular celestial events of the year, a partial solar eclipse.

The Astronomer had been uncharacteristically organized, sending out notices to the Efrat email list the night before, checking all his equipment, lining up his children to help him.  I, the Astronomer's wife, kept a low profile and resolved to sweep up any pieces.  Plus, our neighbor Batya was giving a shiur that morning and I didn't want to miss it, especially for something I considered rather pedestrian, a mere partial eclipse, a paltry 24% coverage.  I'd skip it and see that the essentials (feeding kids breakfast, delivering children to school, being available to comfort the Astronomer should clouds run the whole plan amuck and he find himself alone on a street corner waiting for a patch of blue sky that would never come.

However, I had forgotten about the simple fact that, well, a solar eclipse, even a partial one, is really neat.  Words like "WOW!" and "SO COOL!" come out of the mouth involuntarily.  This was Becky's fault, really.  She needed a ride to school and the Astronomer had seen fit to give her a pair of sun filters so she could admire the eclipse in the car on the way there.  I was driving along, minding my own business, but it was just too much, having her there in the front seat, gawping up at the sun.  So I pulled over the car, grabbed the glasses from her, and took a look.

Suffice it to say I oohed and aahed.  Then I decided that everyone had to take a look at this.  I mean, everyone was just driving around as though it was a regular Friday morning; probably they had no idea there even was a solar eclipse.  Becky and I stayed there as long as we could, staring up with those funny glasses, but to my disappointment, though we garnered a few funny looks, no one stopped to ask what was so interesting.  Perhaps they feared I would tell them, at length.

So we tried another tack.  We picked up a few hitchhikers and Becky handed them the glasses.  They oohed and aahed and asked questions and stared some more and oohed and aahed.  One was a teacher, and I was tickled pink, thinking of how she was thinking of how she'd weave this wonder of the universe into her morning's lessons.  I dropped Becky and the other hitchhikers at their school, then hurried to the street corner to watch the Astronomer at work before I'd have to rush off to shiur. 

A happy, if modest, crowd had gathered around at the street corner, staring through filters or through the filtered telescope, or through pieces of those pinholed papers that show the eclipse's image onto a second paper.  Everyone was very happy, everyone was asking questions, the Astronomer was in his element.  Our own Sharon Katz, not, by her own admission, an early riser (oh, come on, it was well after 8AM!) had come especially to film the event and interview the Astronomer about eclipses and new moons and the molad.  He explained (patiently, and not for the first or the second time) that the molad is not the visible new moon we Jews think of in connection with Rosh Chodesh, the new month.  Rather, the molad is the conjunction of the moon and sun that happens every month.  Usually, this conjunction doesn't result in an eclipse because the moon is either above or below the sun as their paths cross.  Occasionally, however, the moon is right between the earth and the sun, blocking the earth's view of the sun, which we on earth experience as a total solar eclipse.  More frequently, the conjunction  is a partial one; that is, the moon blocks only a section of the sun, which we on earth see as a partial solar eclipse—only if we happen to look up (with our solar filters, of course).

In the shiur I attended later that morning (after I tore myself away from the excitement at the street corner), someone mentioned that the study of nature might lead to man's worshiping nature instead of nature's Creator.  Instead of letting our learned teacher response, I butted in (still bubbling over with residual excitement) that today's celestial event, the partial solar eclipse, was an excellent example (imho) of the opposite: A person who studied nature might conclude, for example, that the sun—powerful, the source of our life—was worth of being worshiped.  And yet, a simple observation of a regular phenomenon like a partial solar eclipse showed clearly that powerful as the sun is, a small, relatively insignificant object like the moon can block its light and its warmth.   Moreover, the moon does so on a regular basis!  Something else is in charge, something else is in control . . .

Sharon asked the Astronomer, "Are there really so many celestial events happening all the time, or do we just hear about them because we (Efratians) have you?"  The Astronomer laughed and said, "There really are events happening all the time: You just have to know where to look."

Keep looking up!

Sharon's blog and video, featuring the Astronomer

And here's a link to the Astronomer's own photos:

Gadi's report and lovely photos too:

Thursday, January 14, 2010

Sunspots are back!

After a very quiet season, we have some new sunspots.
Thanks Gadi for pointing this out.

Just looking at the sun with a filter will not show them as they are usually too small, but if you set up a projection with a small telescope or binoculars you can. Or if you want to be really lazy, or just view them at night, you can see almost live pictures at Space Weather

See if you can find them during the partial eclipse on Friday.

24% Solar Eclipse this Friday morning

On Friday Jan 15th there will be an annular solar eclipse over central Africa and the far East. Here in Israel it will be partial with a maximum of 24% of the Sun covered by the Moon.
 Partial Eclipse

Most people will not notice anything unusual, as even 76% of the Sun is very bright.  However, anyone with the correct equipment for viewing the sun will be able to see an obvious bite missing at the peak of the eclipse.

For safe solar viewing methods, see these:

Solar eclipse Friday, Jan 15:
06:41 Sun (& Moon) rise
07:04 partial eclipse visible in Israel
08:03 peak of eclipse in Israel (24%) 15 degrees above SE horizon
09:11 end of eclipse in Israel

(and for you calendar freaks):
09:12 molad
13:23 average molad

This will be a great opportunity for some sidewalk astronomy. So invite your friends and neighbors and show them a bit of solar system choose a location with a good view of the eastern horizon. To double check, go out a few days earlier at 8am and note where you can see the Sun.

If you are planning something please share it with the list at 

Solar Viewing Safety

I have had a few inquiries asking for details about safely viewing the sun, so I will summarize below.

For the full details see NASA's Fred Espenak Mr. Eclipse page.

There are 2 basic safe ways to view the sun (it does not matter if it is partially eclipsed or not).

1) Projection method.
    This involves using some kind of lens to project an image of the sun onto another surface.The simplest "lens" is just a pinhole. You can easilly make a pinhole in a piece of cardboard,
    Photo: Use Your Handsor even just use your fingers!

    2) Filter method
      You will need filter especially made for viewing the sun.

      You can get these in Israel or online. E.g.
      You can also use a number 14 (or better)  welders glass. These are available locally in many hardware stores.

      Here is a quick and easy projection method from the Exploratorium.

      How-To Images
      (Click on the image for expanded instructions)
      If you want, you can use only two pieces of cardboard--one piece colored white to project on to, and the other with a pinhole. Hold up the pinhole as far from the screen as you can. Remember, the farther you are from the screen, the bigger your image.
      Photo:Tree ShadowsPhoto: Use Your HandsGetting even more basic, you can use your own hands. Just hold up both hands with your fingers overlapping at right angles. The holes between your fingers make pinholes.
      If you have some shade trees in your location, try looking at the images of the sun coming through the holes formed by the leaves. A piece of white posterboard is all you may need to have a great viewing session!

      Or if you have a simple pair of binoculars you can these instructions from NASA:

      Wednesday, January 13, 2010

      Eclipse photography

      Gadi has posted a very nice video of the last lunar eclipse  with instructions on how to do it yourself on his blog

      Tuesday, January 5, 2010

      Friday, January 1, 2010

      2010 Hebrew Astro Calendar

      From: Gadi Eidelheit

      Hi All. Igal Pat-El just finished his 2010 Astronomical Calendar. A must have for all of us

      Ptolemy's Cosmology

      Last night I was discussing the Rambam's view of the planets with my friend Aviad. Rambam basically used Ptolemy's erath centered model. I remember I once came across a great animation on the web, but could not find it. Well now I have, so I thought I would share it with all of you.

      Flash animation of Ptolemy's universe. (needs MS Internet Explorer)

      It shows the whole known universe and you can scale in to just see the center (earth & moon) or the whole cosmos, which did not include too much in Ptolemy's day. You can really get a good idea of what Ptolmey meant by "solid crystalline spheres", and how they all fit exactly one in the other.

      Actually, before you watch that one, you can check out this much simplified Java simulation of the Ptolemaic System - (at Paul Stoddard's Animated Virtual Planetarium, Northern Illinois University) This shows the whole solar system at a glance without the correct scale or many of the details.

      While I was searching, I came across another site Geocentricity by the Association for Biblical Astronomy
      This is an apparently Christian site, but probably most Haredi (and Orthodox?) jews would agree with most of the conclusions.  Kind of scary.