Earth, Orbit, and Climate Presentation and Lunar Observing, Thurs., June 28

This Thursday, the Temecula Valley Astronomers will provide an indoor presentation followed by some lunar and planetary observing at the Temecula Library. The indoor presentation begins at 6:30 and observing of the moon can begin at approximately 7:45. By 8:15, Saturn will be visible in telescopes. Observing will end before 9:00 pm when the library closes.

I will present "Earth, Orbit, and Climate." My presentation is a illustrated look how the science of astronomy contributes to our understanding of climate change. I cover the Sun, the greenhouse effect, climate sensitivity, paleoclimate data, and Earth's changing orbit. Below is a sample from the section describing the greenhouse effect.

I have given this talk to middle school students, so I hope the illustrated nature and my simplifying of concepts, makes this presentation suitable for a broad range of learners. Some graphs and technical explanations are necessary, but most will have the simplicity of the above illustration.

After the presentation, the Temecula Valley Astronomers will have a few telescopes set up for some observing of the moon and Saturn until the library closes.

jg

American Medical Association reports that night light is a health hazard

The following article describes the AMA's new policy recognizing health and safety hazards of night lighting and recommending further research:

Night Light Can Harm Your Health

jg

Great group of sunspots

It is June 16 and I'm seeing a spectacular group of sunspots. My photos were taken with a white-light solar filter at about 40 and 100x magnification. I always add a little yellow, though the sun is white. And I applied unsharp masking in Photoshop to sharpen the details.

jg

Venus Transit at Borrego Springs

On June 5, I observed and photographed the 2012 transit of Venus from Borrego Springs. Though the skies were clear, it was quite windy, so most of my photos were distorted. But of these, a few serve to tell the story of this rare siting.

This isn't first contact, but rather, first presentable photo nearest to first contact:

Below shows Venus taking a bite out of the sun:

The teardrop effect can be seen here. Though, I can't claim the effect is a genuine tear drop instead of distortion from the wind.

And another, almost teardrop effect:

A few minutes into the sun:

Here is a close-up of the anti-teardrop effect. A few of my photos at second contact (the point Venus appears fully in front of the sun's disk) showed a bulge of the sun where a teardrop shadow should be. Is it my viewing conditions or something else?

As the transit progressed, the clarity of my images got worse. As of today, I've examined only a third of the photos.

UPDATE: A few more photos added:
This one is my last clear image at this magnification:

As the sun got lower in the sky, I shortened the focal length to get a smaller image. The smaller image showed less of the atmospheric distortion:

jg