Comet 46P/Wirtanen in 3-D

A big story lately in the astronomy community has been the passage by the Earth of Comet 46P/Wirtanen. The comet was discovered in 1948 by the American astronomer Carl A. Wirtanen of Lick Observatory. It has a period of orbit around the Sun of 5.4 yrs. What makes it so noteworthy now is how close it has come to the Earth, about 30.1 times father than our Moon. This image shows the comet’s orbit as an elongated light grey ellipse. The orbit is tilted slightly with respect to the plane of the inner planet orbits. Earth’s orbit is the 3rd one out from the Sun in light blue.

JPL | Small-Body Database Browser

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Comet 46P / Wirtanen

There has been much news hype lately about a special Christmas comet zooming across the sky. It is perfectly place for observers in the northern hemisphere. Two nights ago (14th) I scanned the sky with 15x binoculars below the Pleiades. There was a very faint smudge of light. Maybe that was it. We set up our 4.25″ Astroscan scope. I was convinced. Melanie less so.

Last night (15th) was especially clear. I set up the 8″ Celestron. This time it was brighter due to the bigger scope. (2x diameter = 4x light) Quite a lovely sight. But, without special equipment, there is no way I could have seen it as hyped in the news. Stories like that suggest to readers there is something special to see. They go look, see nothing, and mutter what a waste of time. Stupid science!

With good seeing conditions, proper equipment and techniques, the comet is a beautiful thing. Here is an image by Sven Melchert of Stuttgart, Germany. He captured 68 images and used software to ‘stack’ them into a composite which produced one high quality image.

For more images of the comet, click on the image below. It will direct you to a new url where you can click on any thumbnail for a detailed view. Consider bookmarking the site for return visits. If you are an astronomy buff, the site always has new and interesting images.

Inverted | Reduced | Virtual

Time for a physics lesson. I picked up a little 3″ diameter concave makeup mirror and looked at myself up close. It enlarged my image and looked upright. I extended my arm slowly while looking at myself and noticed my image got bigger and blurry. As I moved the mirror farther, my image inverted and started to get smaller again. I wondered how my image would look if the mirror was across the room. I stood it on the mantle in front of the clock. I was barely visible.

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I Made It to Mars

UPDATE: InSight landed successfully on Mars on 26 Nov 2018. The microchip with my name and 2.4 million others is now resting on Mars attached to the spacecraft.


6 Nov 2017: My bags are packed. I am ready to join 2.4 million other passengers as we begin our journey to Mars in May 2018 aboard the INSIGHT spacecraft. The trip will take about 7 months. It is a one-way journey.

Click to read the fine print. My flight miles award will be enormous.

INSIGHT is the acronym for Interior Exploration using Seismic Investigations, Geodesy and Heat Transport. NASA loves acronyms. Previous Mars missions have studied intensively the surface and atmosphere of the planet. This spacecraft is the first designed to study the interior in hopes of finding clues to the formation of the rocky inner planets. The spacecraft will use seismology, heat flow equipment, and very precise tracking to probe the planet below ground.

Noon @ Ollantaytambo

We climbed the 245 steps to the top of the Inca ruins at Ollantaytambo in Peru and reached the Temple del Sol. It was noon with the sun high overhead. Someone looked up and noticed an ice ring encircling the sun. I had to capture this photo.

I grew up and continue to live at about 40-42˚ north latitude in the center of the U.S. The sun has never been directly overhead. But now, at noon about 13˚ south latitude, the sun was nearly straight up. I looked down to my feet and saw something I’d never seen before. My shadow was directly below me. That was fun to see.