SpaceX | How They Do Booster Landings

SpaceX, the private rocket launching company owned by Elon Musk, has had successes lately with commercial satellite launches. On 1 May 2017, they launched the military satellite NROL-76 from historic Launch Complex 39A at the Kennedy Space Center in Florida. Another major accomplishment by SpaceX is the successful landings and re-use of the stage 1 booster of the Falcon 9 rocket. This has never been done before, not even by NASA. The way I see it, that story deserves some explanation.

Watch this compilation of clips from the most recent booster landing, their 4th. The landing takes place on an unused pad not far from launch complex 39A a short distance up the coast. I wondered what flight path the stage 1 booster took to allow it to return back to this spot near the launch site. Most of its fuel had been used to get it and the stage 2 payload to high altitude, far downrange, and going very fast. The flight needed to be very efficient.

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Vatican Observatory Tour

I follow the blog The Catholic Astronomer from the Vatican Observatory Foundation. I’ve heard of the Vatican Observatory for a long time but never knew much about it. It sits a above an extinct volcanic lake at Castel Gandolfo in the Papal Gardens near Rome.

© Paul A. Zalonski

Very recently, the observatory director and foundation director led a tour of the place. Joining them was Christopher Graney who is an astronomy teacher in Louisville, KY. He recorded videos for his class to see later. His videos are posted here on the blog site.

Scroll to the bottom of his post and click the left of three small images about the history and telescopes. His link will take you to the three videos.

One aspect of interest in the tour was of the women computers who worked there and their machine used to measure stars on the glass plates. It connected well with the work of the women computers in The Glass Universe by Dava Sobel. Those women laid the foundations for many of the important principles used in modern astronomy.

Pluto | What Have We Learned?

Top findings by scientists with the New Horizons Pluto Mission were published in March 2016 in the journal Science. A list of the highlights is available in this news release from NASA. I will attempt to summarize each finding and their significance.

Images used in this post are from Johns Hopkins Applied Physics Laboratory. Click on any for a much larger and impressively detailed view. Their entire collection of released images is available here for your browsing pleasure. I encourage you to look through the images. Our views of Pluto went from a tiny mottled orb a year ago to ones with great detail and mystery. Each of the 120+ images includes an explanation of the important details.

Now on to the top findings…

1. Geologically active

The ages of solar system bodies can be estimated by counting the number of craters. This method tells us Pluto is about 4 billion years old, a little younger than Earth. The heart-shaped light colored, icy region called Sputnik Planum is devoid of cratering. That indicates it is young no more than 10 million years. Sputnik Planum is smooth and about the size of Texas.

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Dawn | Views From LAMO

The Dawn spacecraft is in low altitude mapping orbit (LAMO) around the dwarf planet Ceres at an altitude of 240 mi (385 km), closer than the Space Station orbits Earth. Amazing detail is being imaged and analyzed. Some of those features are highlighted in this brief Jet Propulsion Lab video. Visit this link for previous posts about Dawn.

 

A recent enhanced image in color of Occator crater. Click to embiggen for greatest detail.

Space Station Transit of the Sun

8 May 2009 Transit

With a solar filter over the lens, I aimed my video camera at the Sun and zoomed to get a full screen view. The tripod mount held it steady. The transit took only 2 seconds. I let the camera record for several minutes, then rushed home to see if the ISS was visible on the recording. This video is slowed down to make it easier to follow. Else, you might blink and miss it.

 

How Did I Know It Would Transit?

Each week, I get an email notice about upcoming events such as ISS passes over my location. I can go out in fair weather and watch it go over. It is as bright as Venus and moves fast. Every few months, the Sun or Moon is positioned so the ISS passes across their face as viewed from my location. The email alert tells me where and when to be positioned so my view has the ISS pass across the center of the face. I got one of those alert emails a few days ago.

This map shows a centerline of the ISS in front of the Sun for the morning of 27 Feb 2016 at about 7:38m59s am CST. It plots every 0.5s. I live quite close to the line and positioned myself where it crosses 380.

ISS_SunTran

 

27 Feb 2016 Result

I planned to test a new set of equipment for recording the event. According to the email alert, the small silhouette of the ISS would pass from right to left across the center of the solar disk. I let the camera record long enough to capture the transit and then hurried home to check the results. You can judge for yourself in the video below. It has been shortened in order to show the transit.

 

Either I completely missed capturing the ISS and got a gull transit instead. Or, the ISS has been fitted with a pair of flapping wing solar panels. That seems very unlikely. I hope to have better luck next time.

 

6 Sep 2015 Transit

Here is a high quality video of a transit as seen 6 Sep 2015 from Shenandoah National Park, Front Royal, VA.  Credit to NASA/Bill Ingalls.

ISS Solar Transit (NHQ201509060002 - animated)

Gravity Waves | Both LIGO Record Them

A little more than 1.3 billion years before 14 Sep 2015, a pair of 29 and 36 solar mass black holes orbited each other, slowly getting closer together. On that date, they merged into one black hole of 62 solar masses. Their merger radiated 3 solar masses of energy in a fraction of a second.

This animation from Simulating Extreme Spacetime SXS uses calculated effects from the equations of Einstein to simulate the view of the star field behind the black holes. Imagine you are close enough to watch their dance. Paths of starlight are altered by the masses of the black holes. It is also greatly slowed down. The black holes were actually moving a high fraction of the speed of light as they orbited just before merger.

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