Venus | Inferior Conjunction | 2017

Venus is closer to the Sun and orbits faster than Earth. Earth takes just over 365 days. Venus orbits in just under 225 Earth days. During the recent few months, Venus was bright and easily visible in the evening sky as it caught up to and passed Earth. In doing so, it came closer and appeared larger when viewed with a telescope or binoculars. This animation from a desktop program illustrates their motions. Mercury is not shown in order to simplify the view. The sizes are exaggerated.

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Analemma On My Wall

A prism of high quality glass sits in a south window above our mantle. It is part of a surplus optical instrument from WW-II. The window crank gives a sense of its 2″x1″x1″ size.

prism

When the Sun is low in the sky during late fall and winter, light through the prism casts a large full spectrum on the wall on the opposite side of the house. This is a closeup of the spectrum. It is always a delight to see the colors move slowly across the wall during the middle part of a sunny day.

viewspectrum

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Venus | A Narrowing Crescent

Viewed from Earth, the crescent of Venus narrows each day as it orbits the Sun. On 25 March 2017, it will be aligned almost directly between Earth and the Sun. In the weeks following, Venus will appear as a morning object and a thin crescent. Go here to see a 3D tool showing the orbital positions of the inner planets today. Notice the Date and Date Slider controls where you can change the date and see the planets move.

2017_0215venus3

Venus 15 February 2017

 

Date Time Digitized: Feb 15, 2017, 6:05:33 PM CST
Exposure Time: 1/500 s
Photographic Sensitivity (ISO): 100

 

Solar Transit | It Happened Again

Five days ago I received a notice that the space station would transit across the face of the Sun for my location. I wrote about a recent transit on 18 August 2016. I must be living right. The sky was clear again this time.

First view is in real time. Don’t blink. Duration of the transit is 0.94s. Second view is slowed to 10% of real time. For both, I suggest full screen. You might not see it on a phone or tablet.

 

What’s up for the rest of the month? This JPL video will tell you of some highlights.

Solar Transit | ISS Crosses the Sun

I’ve been waiting patiently. Today, three parts of a challenge finally came together. The sky was clear. I had the correct video equipment. And, the International Space Station crossed the face of the Sun as seen from my location. I received an email notice from CalSky this morning about this event. The track of the centerline was directly over our communities. I had to be ready in about an hour if I was to record video of the event.

I put the solar filter over the lens of my camera and put it on the tripod. I stepped outside to test the video settings. A test video of the Sun turned out as I hoped. I went inside and set a timer. The transit across the Sun was to occur moments after 1:03 local time. I figured to record from 1:02 until 1:04. The transit would show a silhouette of the ISS for only 0.6 seconds since it is going so fast at 5 mile/sec. I used my cell phone to accurately keep track of time. It was within a second of the national atomic clock.

Here is the result. The video is slowed down to half speed. Transit occurs about 6 seconds into it. You can slow it down even more with the gear tool on the video panel.

 

I was thrilled with the result. This isn’t the first time I’ve recorded a transit. Others are here and here. But, this is by far the best quality. I am still waiting for an opportunity to record an ISS transit of the Moon.

Here is a sequence of superimposed screen shots from the video showing a more detailed look at ISS. Two large solar array panels are quite visible. Total transit time was 0.6 sec. Each position of ISS is about 0.1 sec apart. Notice a few small sunspots left of center and to the far right limb. The faint concentric rings are imaging artifacts and not real. North is to the top of the frame.

2016_0818ISS_SunTrans

Mercury | Rare Transit of the Sun

Mercury passes between the Sun and Earth during the day on 9 May 2016 allowing us to see it in silhouette for about 7 hours. It happens only 13 times per century. What is expected and how can it be viewed safely? Full details here for those knowledgeable in the technical bits. This NASA article is also very informative. For the rest who don’t feel technically savvy, follow me farther down below in this post.

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Solar Eclipse | 8 March 2016 | Images

The regions of Indonesia and Micronesia were blessed with mostly clear skies during the recent solar eclipse. The track of the umbra shadow shows a purple marker where the duration of total eclipse was the longest at just over 4 minutes. The island of Woleai was in the ideal location near that marker. The eclipse was in the morning of 9 March for them, but in the evening of 8 March east of the dateline.

EclipsePath

 

This video, images courtesy of Japan Meteorological Agency with data courtesy JMA and NOAA, shows the progress of the shadow of the Moon seen from the Himawari-8 weather satellite. The colors are true. Cloud movements are also visible.


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