Category Archives: Science

Fly the Line & Learning about “Airframes”

June 21, 2017

It was basically a straight line from Palmdale, CA (outside Los Angeles) to Honolulu, Hawaii: a lot more relaxed than a normal SOFIA science flight, which has all those legs and turns enable doing the astronomy (the telescope is only located on one side of the plane, combined with targets rising in the east/setting in the west).

I got a chance to hang out in the cockpit and spent time with Steve, the Flight Engineer, who walked me through the small changes pilots Dean and Paul needed to do from time to time. There was a kind of camaraderie among these three men, who yes, have flown together, but not flown a lot together recently, as Steve lives in Denver working for United, and Dean and Paul are off flying ER2s and other NASA “airframes.” They all knew how to do their jobs and kept each other vigilant on monitoring the many dials, doing tweaks to elevation, turning on the engine heaters by hand (as a known precaution) for 1 minute every 30 minutes (unless the engine oil gets to -5 C and then its 1 minute every 10 minutes), refreshing their knowledge about the weather, etc. etc. Apparently when you do most of your flying out of the desert, you get used to “no weather” and where we’re headed down south (to New Zealand), we’ll get “some weather.”

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The rest of my fellow passengers are a mixture of mechanics, software engineers, telescope operators, and avionics technicians (techs). I learned from my seatmate, Darrell, about how the wings of the 747SP uses hydraulics rather than screw types for adjusting the lift. This was a more efficient design that enables long-haul operations (go to Europe from the US in one flight). I had remarked that when I fly on airlines, depending on the “airframe” sometimes as part of the pilot’s checklist you can hear the whirring noises in the wings, which Ken called out to be the screw adjustments, which are not present in all “airframes.” Not everyday you get to fly next to folks who know how to build aircraft.

 

 

$400 Chicken Nugget

June 20, 2017

I wandered to see our beautiful flying observatory, settled in her home at Bld 703 in Palmdale, CA, in the hangar to keep cool. Temperatures down here in the desert got to over 107 F (42 C) this week.

SOFIA June 20, 2017

Chatted with three mechanics, before they went home for the day, who will be on the flight out to Christchurch New Zealand. All had been on the prior deployments. They commented on how cold it will be there in New Zealand (as we have this conversation in over 100 degree F weather). One actually shipped some long johns courtesy of Amazon. Now that is planning ahead. They specifically mentioned to bring bags full of warm clothes, but no wool. Something about wool not liked by New Zealand customs? Oh and food, if not declared. Their advice to me. Declare everything. Most likely all the food will be confiscated by customs. If I don’t declare contents I would face a hefty fine. Apparently one of the SOFIA team had to pay for a $400 Chicken Nugget. Now that’s food for thought.

My bags are full. The plane is ready. The adventure begins tomorrow.

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A photo to get you to think about light and physics

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I am always proud of my hubby, Robert, and especially now, as he combined his love of photography (a special hobby of his) and astronomy and went one step forward and created something new to start conversations.

Did you know he won the Insight Astrophotographer of the Year 2016 award for the special category Robotic Scopes?

He was trying to convey not just the beauty of spectra (spreading light into different colors), but how much it can tell us about the object we are observing (what it’s made of, what’s going on, etc.).

He used data from a public archive of the Liverpool Telescope, a 2-meter robotic telescope on island of La Palma in the Canaray Islands, and combined imagery and spectra  to show off the beauty and the physics of two commonly photographed planetary nebulae (both readily seen from northern hemispheres): Cats Eye Nebula (NGC 6543 in Draco) and the Ring Nebula (M57 in Lyra).

Artistically arranged to show the colors of the rainbow, which helped inspire us to name the piece Iridis, which is latin for rainbow.

Nice writeup at the Liverpool Telescope website can be found here.

The Many Faces of Pluto and Charon

Reposted from https://blogs.nasa.gov/pluto/2016/02/12/the-many-faces-of-pluto-and-charon/.

Today’s blog post is from Kimberly Ennico, a member of the New Horizons’ Composition Theme Team and one of the deputy project scientists. She works at NASA’s Ames Research Center in Moffett Field, California, and has been on detail to the Southwest Research Institute in Boulder, Colorado.

No one can doubt the beauty of Pluto and Charon—amazing worlds revealed by the images from NASA’s New Horizons mission. From Pluto’s mountains, glaciers, ice-volcanoes, blue skies, and layered colorings to Charon’s vast tectonic structures and enigmatic red-colored pole, these pictures and associated spectra are rich puzzles waiting to be solved.

The July 14, 2015 Pluto flyby gave us an initial look at one side of Pluto, with its iconic heart-shaped feature. But I’m interested in the full planetary perspective, finding the “other sides” of Pluto to be every bit as fascinating as the encounter hemisphere. We must remember that a flyby is a moment in time lasting a few hours. In contrast, Pluto and Charon each rotate about its axis every 6.4 Earth days. This means that when New Horizons flew through the Pluto system it captured one hemisphere of each body in incredible detail.

What do we know about the “other sides” of Pluto and its largest moon? In the three weeks before the flyby, the Long Range Reconnaissance Imager (LORRI) and Multispectral Visible Imaging Camera (MVIC) imaged Pluto and Charon every day, sometimes two or three times a day to gather as much coverage across the bodies as New Horizons closed in. LORRI is New Horizons’ primary camera, an 8-inch telescope outfitted with an unfiltered charge-coupled device (CCD) – like you’d find in your own digital camera – sensitive to visible light. MVIC is a separate instrument with multiple CCDs, for which several are outfitted with color filters. The highest resolution images of the “other sides” of Pluto and Charon were observed 3.2 Earth days earlier, around July 10-11.

Working with a subset of the data (as not all these images have been sent to Earth from New Horizons yet), we’ve received our first glimpse of these “non-encounter” hemispheres below.

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Four faces of Pluto in black-and-white and color. From left to right, the central sub-observer longitudes are ~180, 240, 360 and 60 degrees East Longitude. The Pluto “Encounter Hemisphere” (indicated by the white box) is most recognizable by the “heart” feature of the informally-named Tombaugh Regio. This is also the hemisphere that today never faces Charon, as Charon is “tidally locked” to Pluto, similarly to how the Earth only sees one face of our moon. Pluto’s “Charon-facing” side is the second column from the right. Pluto’s north pole is up in all these images. The top row contains LORRI grey-scale images taken on July 13, July 12, June 27 and July 3rd, when Pluto was 620, 189, 24 and 36 LORRI pixels across, respectively. The bottom row shows MVIC “enhanced-color” images made by combining the near infrared, red and blue filters. They were taken on July 13, July 12, July 10 and July 9, when Pluto was 163, 56, 26 and 21 MVIC color pixels across, respectively. All these images surpass what we had previously seen from Hubble Space Telescope imagery where Pluto’s disk was only about 12 pixels across. Of course, New Horizons was only millions of miles from Pluto—Hubble is over 3 billion miles away! Credits: NASA/JHUAPL/SwRI

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Six faces of Charon. Central sub-observer longitudes: top, from left to right, 350 (B&W), 2 (color), 32 (color); Bottom, from left to right, 67 (color), 86 (B&W), and 180 (color) degrees East Longitude. The side that faces Pluto is highlighted by the inset box. From left to right, the top row images were taken July 14, 14 and 13, 2015, with Charon spanning 523 (LORRI), 81 (MVIC), and 43 (MVIC) pixels. The bottom row images were captured from July 12, 12 and 10, 2015, with Charon spanning 28 (MVIC), 96 (LORRI), and 13 (MVIC) pixels. Charon remains a mainly neutral greyish color all around, with a distinct red northern polar cap appearing from all sides. Credits: NASA/JHUAPL/SwRI

What strikes me most about the new Pluto color images is that the latitudinal (horizontal) banding identified on the encounter hemisphere is evident all around Pluto. Specifically, the northern polar region has a distinctive color from adjacent latitudes. The darkest region, which spans the equator, also appears to continue around Pluto, showing distinct variations on the side facing Charon, which have yet to be understood.

Why is this interesting? Coloring on Pluto is thought to have been the result of hydrocarbons called tholins that have formed in the atmosphere and have been “raining” down on Pluto’s surface over the millennia. We’re investigating whether Pluto’s colored terrains are primarily due to changes in or movements of its surface ices, specifically whether they have been undergoing seasonal effects –changing in temperature over time from the amount of cumulative sunlight – which could display itself as horizontal banding. The presence of that vast reservoir of methane, nitrogen and carbon monoxide ices in Pluto’s “heart” complicates the picture and could serve as a visible marker to trace changes.

Over the next few months, as more of this late-approach imagery gets downlinked from the spacecraft’s recorders, we will continue to piece together this colorful story of Pluto and Charon – from all sides.

Getting ready for the 2015 Pluto encounter. 2014 summer’s annual checkout brings high data payoff.

Reposted from http://pluto.jhuapl.edu/News-Center/Science-Shorts.php?page=ScienceShorts_07_11_2014.

You walk up to the Restaurant at the End of the Solar System, ready to try that slice of “Pluto on ice” that you heard amazing things about. The chef behind the counter asks, “So, how would you like your data? “ Without hesitation, you reply “Well calibrated.”

Pretty pictures or spectra make no sense “without context.” For images, we need to know how many kilometers map to a pixel and for each raw digitized value, a mapping from bits to energy units (like magnitude or ergs/cm^2/s). For spectra, we need to know how much spatial information is covered per pixel plus what each pixel’s response to wavelength and brightness is. For particle instruments, we need to what energy and from which direction that ion or dust grain came.

Before launch every New Horizons instrument underwent intensive laboratory characterization: “pre-flight calibration.” They were subject to spatial targets, integrating spheres, laser pulses, particle accelerators, to name a few good “known” sources, to get “translations” from bits stored to disk to “real” units like wavelength, flux energy, intensity, etc. After launch such “translations” were verified with “in-orbit” calibrations, where, for example, instead of a lab source, the instruments stared at stars or inspected Jupiter and its moons. Each year, the team executes an ACO, or Annual Check-Out, where instrument performances are trended and teams look for changes. Additional observations provide information to remove “unwanted artifacts” like hot-pixels, readout smearing, ghosts, etc.

Summer 2014 is ACO-8, our 8th annual checkout since launch. It showcases our last calibrations prior to the 2015 Pluto encounter. It’s jammed packed with observations that are done yearly for trending, but also some new ones to make sure the New Horizons instrument suite is “well calibrated.” Highlights include new radiometric calibrations for the LEISA IR spectrometer, a long stability test for the REX radio experiment, and a test for revised thresholds for PEPSSI, the high-energy particle detector. More calibration data is taken during the 2015 Pluto fly-by, and together, these data sets are placed in the data reduction pipeline to translate bits to “real” values. Resources and time aboard the spacecraft to execute these observations are limited, so a series of reviews and assessments are done prior to each checkout.

The team is eager to get the data from ACO-8. We wake up June 15th. After a similar series of spacecraft subsystem checkouts, the New Horizons payload calibrations begin and continue through August. It may not be the Pluto fly-by, but this summer’s data will play a big role in the science return from New Horizons next year!

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Demonstration of read-out smear removal, preserving the photon count, in LORRI’s calibration pipeline. The data in the smear is caused by imperfections in the CCD readout when illuminated by a lot of light. The source of the photons is from the object being imaged, so we need to correctly relocate the information. Data without good calibration is messy.

 

As a New Horizons deputy project scientist, Kimberly Ennico manages instrument readiness and calibration aspects of the mission. Her expertise includes instrument development, space qualification and calibration; optical/infrared astronomy; optical/infrared detectors, optics, cameras and spectrometers; and science communication.