The astronomy community has reported a confusing phenomenon in recent years that the universe is composed of mostly matter and energy we don’t understand and cannot see. The terms dark matter and dark energy are used to describe these unknowns. I posted earlier about their confusing nature. The normal matter we can see and measure comprises only about 5% of the universe. The remaining 95% is ‘dark’ to us. Not dark in the sense of absence of light. We are unable to see it in the same ways we detect ordinary matter. The distribution is depicted here by Chandra X-Ray Observatory.
Progress is being made toward the detection and better understanding of the distribution of dark matter and dark energy. The progress uses techniques which infer the presence of something invisible which affects the visible normal matter. Techniques such as gravitational lensing are used. Theories are tested to see if observations match predictions. Progress is slow and difficult.
There are some very smart people working on this puzzle. Two of them are a wife-husband team who work at the Jet Propulsion Lab JPL in California. Alina Kiessling and Jason Rhodes are Astrophysicists with NASA-JPL. On 17 October 2019 they presented the public talk linked below for JPL’s Theodore von Kármán Lecture Series. It was one of the best programs on this topic I have seen.
In their program, they explained aspects of dark matter and energy, how it is detected, and what might be the ultimate fate of the universe. All was done in a manner that was not technical or overwhelming and included entertaining and humorous examples. At the end they answered audience questions.
My hopes were high to be able to see Mercury during transit with my own optical equipment. But, the weather didn’t cooperate. Our morning was cloudy as 2″ of snowfall was ending. A few moments of sunshine came as the transit ended. But, efforts to get a photo failed. Instead, I visited the space-based Solar Dynamics Observatory to watch the event. They put on a great show at their dedicated transit site. The images and videos are archived there and can be visited any time.
Here is a sample. Watch the planet Mercury cross from left to right during the 5.5hr event. It is very small. This video and all images in this post are “Courtesy of NASA/SDO and the AIA, EVE, and HMI science teams.”
Perhaps you wondered why the Sun looked an odd color and appearance. That is because of the wavelength of light used. SDO simultaneously images the Sun in 10 wavelengths. It takes images in 10 wavelengths every 10 seconds. Those are stitched together to show the dynamic activity of the Sun. For example…
The transit was tracked as it started (ingress) in the multiple wavelengths below. Each wavelength is associated with different temperatures and energies at the Sun’s surface. They are colorized to make them easily distinguished from the others. SDO also tracked Mercury in a magnified view as it made its way across and also at the end of transit (egress).
“Courtesy of NASA/SDO and the AIA, EVE, and HMI science teams.”
As the transit unfolded, I captured short videos in the different wavelengths as Mercury was tracked. These videos were stitched together into a smooth transition from one color to the next.
The next transit of Mercury will be in 2032. The orbit of the planet is tilted with respect to our orbit and prevents a transit alignment for quite a while. Don’t hold out hopes for the next Venus transit. It will not occur until 2117.
I watched the 7 hour spacewalk and was impressed by the amount of work, the quality of the jobs done, and how difficult it was. Here is the follow-up news conference by NASA astronauts Christina Koch and Jessica Meir. If you have contact with young women at home or in the classroom, share with them.
Generation of electricity by the panels has been monitored for the six most recent days. The days varied from sunny, to cloudy, and variable. The output by the panels varied, too. The blue bars are total electric energy generated for the days of October 9-14. At the top of each is the kilo-Watt-Hours (kWhr) of electric energy made by the panels that day. During those days, total electric energy usage by our home averaged 5.52 kWhr. Generation is keeping pace with usage.
Perhaps you’ve heard the phrase ‘Never in a month of Sundays’. I offer you a month of sunrises between 30 Aug and 26 Sep 2019 out my front window. Bright streaks were caused by the sun shining through the hole of the pinhole camera onto light sensitive paper. Missing sections were caused by clouds blocking the sun. The streak farthest left was from 30 Aug. The one farthest right was from 26 Sep just after the autumn equinox when the sun rises directly east.
A solargraph of the same scene was made during a week back in late May which yielded this set of lines. East is in the center of the image. Northeast is the left edge and southeast is the right edge of the view.
Using Photoshop Elements, I copied the May exposure onto the more recent one to illustrate how far the sun had progressed south as the summer ended. It will track even farther as it moves into the winter months reaching its most southern position at the winter solstice. The pinhole camera is currently set up to record for the next 3 months.
More information about solargraphs can be found at this post.
Sean Carroll is the host of the Mindscape podcast. In this recent interview, he spoke with author, technologist, and entrepreneur Ramez Naam. They discussed why the outlook for renewable energies could suggest we be optimistic about them. I invite you to listen. Check out some of the other podcasts while you are there.