JWST | Sunshield Measurements

Smarter Every Day author Destin interviewed his dad in 2016 who was working on the sunshield layers that were eventually placed on the James Webb Space Telescope. His dad worked as a metrologist who specialized in using sophisticated tools to accurately measure dimensions of products. In this video, several people explain the complex procedures used to measure the sunshield layers and how the data was fit to models and applied to the L2 point in space. It is a fascinating look behind the scenes at an essential part of the JWST. There is one ad break at the 15 minute time.

JWST | Alignment Progress

The JWST team successfully completed the third phase of mirror alignment by tilting each of the 18 segments to produce one image. This set of stacked images will further be refined by adjusting the heights of the segments to within one wavelength of light. This step is called Coarse Phasing. Details of the recently completed processes are here in their blog.

Ultima Thule | Best View by New Horizons

The New Horizons spacecraft returned this detailed image of Ultima Thule to Earth on 18-19 Jan 2018. It was captured 7 minutes before the closest approach to Ultima Thule at a distance of 4,200 mi (6,700 km). The signal of digital bits traveled at the speed of light for 6 hrs before reaching the antenna at Earth so we could see it.


The shape of Ultima Thule was discovered in July 2017 when it passed in front of a distant star as seen from Earth. Twenty four telescopes were lined up across Argentina where the shadow of Ultima Thule was to pass as it occulted the distant star. The scopes were coordinated with precise time markers. The best-fit of their timings suggested a bi-lobed object. What an amazing prediction considering UT is only about 20 mi (30 km) across and measured from more than 4 billion miles away.

This is probably the oldest and most primordial object we will ever see in such detail.

Ultima Thule belongs to a class of Kuiper belt objects called the “Cold Classicals,” which have nearly circular orbits with low inclinations to the solar plane, and which have not been perturbed since their formation perhaps 4.6 billion years ago. Ultima Thule will therefore be the most primitive planetary object yet explored, and will reveal to us what conditions were like in this distant part of the solar system as it condensed from the solar nebula.


What’s next for New Horizons? Hopes are high for extensions to the mission into 2019 and beyond. It will take into 2020 to download all the data stored in the memory banks. With remaining fuel, New Horizons might survey the field ahead and redirect slightly to pass by other Kuiper Belt objects. Stay tuned to see what might happen.

Ships Passing in the Night

It was 6:30 pm on 24 Jan 2018. The International Space Station was due to pass directly over our part of Iowa from WSW to NE. It was 3˚F outside with more than a foot of snow on the ground. Instead of going outside, I set the iPad in the bedroom window, closed the door, and recorded the pass for 6 minutes. While I watched the spaceship cruise above the trees at 5 mi/sec, an airship also cruised over at about 0.2 mi/sec. The stars silently observed from their perches. I stayed warm.

NightCap Camera | iPad2 | ISO=1536 | 356 sec | Click to embiggen