From NASA JPL-Caltech: “NASA Finds Neptune Moons Locked in ‘Dance of Avoidance'”

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From NASA JPL-Caltech

November 14, 2019
Gretchen McCartney
Jet Propulsion Laboratory, Pasadena, Calif.
818-393-6215
gretchen.p.mccartney@jpl.nasa.gov

Alana Johnson
NASA Headquarters, Washington
202-358-1501
alana.r.johnson@nasa.gov

1
Neptune Moon Dance: This animation illustrates how the odd orbits of Neptune’s inner moons Naiad and Thalassa enable them to avoid each other as they race around the planet.

Even by the wild standards of the outer solar system, the strange orbits that carry Neptune’s two innermost moons are unprecedented, according to newly published research [Icarus].

Orbital dynamics experts are calling it a “dance of avoidance” performed by the tiny moons Naiad and Thalassa. The two are true partners, orbiting only about 1,150 miles (1,850 kilometers) apart. But they never get that close to each other; Naiad’s orbit is tilted and perfectly timed. Every time it passes the slower-moving Thalassa, the two are about 2,200 miles (3,540 kilometers) apart.


An observer sitting on Thalassa would see Naiad in an orbit that varies wildly in a zigzag pattern, passing by twice from above and then twice from below. Credit: NASA/JPL-Caltech

In this perpetual choreography, Naiad swirls around the ice giant every seven hours, while Thalassa, on the outside track, takes seven and a half hours. An observer sitting on Thalassa would see Naiad in an orbit that varies wildly in a zigzag pattern, passing by twice from above and then twice from below. This up, up, down, down pattern repeats every time Naiad gains four laps on Thalassa.

Although the dance may appear odd, it keeps the orbits stable, researchers said.

“We refer to this repeating pattern as a resonance,” said Marina Brozovi?, an expert in solar system dynamics at NASA’s Jet Propulsion Laboratory in Pasadena, California, and the lead author of the new paper, which was published Nov. 13 in Icarus. “There are many different types of ‘dances’ that planets, moons and asteroids can follow, but this one has never been seen before.”

Far from the pull of the Sun, the giant planets of the outer solar system are the dominant sources of gravity, and collectively, they boast dozens upon dozens of moons. Some of those moons formed alongside their planets and never went anywhere; others were captured later, then locked into orbits dictated by their planets. Some orbit in the opposite direction their planets rotate; others swap orbits with each other as if to avoid collision.

Neptune has 14 confirmed moons. Neso, the farthest-flung of them, orbits in a wildly elliptical loop that carries it nearly 46 million miles (74 million kilometers) away from the planet and takes 27 years to complete.

Naiad and Thalassa are small and shaped like Tic Tacs, spanning only about 60 miles (100 kilometers) in length. They are two of Neptune’s seven inner moons, part of a closely packed system that is interwoven with faint rings.

So how did they end up together – but apart? It’s thought that the original satellite system was disrupted when Neptune captured its giant moon, Triton, and that these inner moons and rings formed from the leftover debris.

“We suspect that Naiad was kicked into its tilted orbit by an earlier interaction with one of Neptune’s other inner moons,” Brozovi? said. “Only later, after its orbital tilt was established, could Naiad settle into this unusual resonance with Thalassa.”

Brozovi? and her colleagues discovered the unusual orbital pattern using analysis of observations by NASA’s Hubble Space Telescope. The work also provides the first hint about the internal composition of Neptune’s inner moons. Researchers used the observations to compute their mass and, thus, their densities – which were close to that of water ice.

“We are always excited to find these co-dependencies between moons,” said Mark Showalter, a planetary astronomer at the SETI Institute in Mountain View, California, and a co-author of the new paper. “Naiad and Thalassa have probably been locked together in this configuration for a very long time, because it makes their orbits more stable. They maintain the peace by never getting too close.”

More information about Neptune’s moons can be found here:

https://solarsystem.nasa.gov/moons/neptune-moons/in-depth/

See the full article here .


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Please help promote STEM in your local schools.

Stem Education Coalition

NASA JPL Campus

Jet Propulsion Laboratory (JPL)) is a federally funded research and development center and NASA field center located in the San Gabriel Valley area of Los Angeles County, California, United States. Although the facility has a Pasadena postal address, it is actually headquartered in the city of La Cañada Flintridge, on the northwest border of Pasadena. JPL is managed by the nearby California Institute of Technology (Caltech) for the National Aeronautics and Space Administration. The Laboratory’s primary function is the construction and operation of robotic planetary spacecraft, though it also conducts Earth-orbit and astronomy missions. It is also responsible for operating NASA’s Deep Space Network.

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From NASA JPL-Caltech: “NASA Instrument to Probe Planet Clouds on European Mission”

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From NASA JPL-Caltech

November 8, 2019

Calla Cofield
Jet Propulsion Laboratory, Pasadena, Calif.
626-808-2469
calla.e.cofield@jpl.nasa.gov

Felicia Chou
NASA Headquarters, Washington
202-358-0257
felicia.chou@nasa.gov

Written by Elizabeth Landau
NASA Headquarters, Washington

1
This artist’s concept shows the European Space Agency’s ARIEL spacecraft on its way to Lagrange Point 2 (L2) – a gravitationally stable, Sun-centric orbit – where it will be shielded from the Sun and have a clear view of the sky. NASA’s JPL will manage the mission’s CASE instrument.Credit: ESA/STFC RAL Space/UCL/Europlanet-Science Office

LaGrange Points map. NASA

NASA will contribute an instrument to a European space mission that will explore the atmospheres of hundreds of planets orbiting stars beyond our Sun, or exoplanets, for the first time.

The instrument, called the Contribution to ARIEL Spectroscopy of Exoplanets, or CASE [no image available], adds scientific capabilities to ESA’s (the European Space Agency’s) Atmospheric Remote-sensing Infrared Exoplanet Large-survey, or ARIEL, mission.

The ARIEL spacecraft with CASE on board is expected to launch in 2028. CASE will be managed by NASA’s Jet Propulsion Laboratory in Pasadena, California, with JPL astrophysicist Mark Swain as the principal investigator.

“I am thrilled that NASA will partner with ESA in this historic mission to push the envelope in our understanding of what the atmospheres of exoplanets are made of, and how these planets form and evolve,” said Thomas Zurbuchen, associate administrator for NASA’s Science Mission Directorate in Washington. “The more information we have about exoplanets, the closer we get to understanding the origins of our solar system, and advancing our search for Earth-like planets elsewhere.”

So far, scientists have found more than 4,000 confirmed exoplanets in the Milky Way. NASA’s retired Kepler space telescope and active Transiting Exoplanet Survey Satellite (TESS) are two observatories that have contributed to this count.

NASA/Kepler Telescope, and K2 March 7, 2009 until November 15, 2018

NASA/MIT TESS replaced Kepler in search for exoplanets

These telescopes have discovered planets by observing brightness of a star’s light dimming as a planet crosses its face, an event called a “transit.”

Planet transit. NASA/Ames

ARIEL, carrying CASE, will take planet-hunting through transits one step further, by delving deeper into planets already known to exist.

ARIEL will be able to see the chemical fingerprints, or “spectra,” of a planet’s atmosphere in the light of its star. To do this, the spacecraft will observe starlight streaming through the atmospheres of planets as they pass in front their stars, as well as light emitted by the planets’ atmospheres just before and after they disappear behind their stars. These fingerprints will allow scientists to study the compositions, temperatures, and chemical processes in the atmospheres of the planets ARIEL observes.

These chemical fingerprints of exoplanet atmospheres are extremely faint. Identifying them is a huge challenge for astronomers, and requires a telescope to stare at individual stars for a long time. But many space observatories are multi-purpose, and must split up their time among different kinds of scientific investigations. ARIEL will be the first spacecraft fully devoted to observing hundreds of exoplanet atmospheres, looking to identify their contents, temperatures and chemical processes. The addition of CASE, which will observe clouds and hazes, will provide a more comprehensive picture of the exoplanet atmospheres ARIEL observes.

So far, telescopes have only been able to carefully probe the atmospheres of a handful of exoplanets to determine their chemistries. ARIEL’s much larger, more diverse sample will enable scientists to look at these worlds not just as individual exotic objects, but as a population, and discover new trends in their commonalities and differences.

The CASE instrument will be sensitive to light at near-infrared wavelengths, which is invisible to human eyes, as well as visible light. This complements ARIEL’s other instrument, called an infrared spectrometer, which operates at longer wavelengths. CASE will specifically look at exoplanets’ clouds and hazes – determining how common they are, as well how they influence the compositions and other properties of planetary atmospheres. CASE will also allow measurements of each planet’s albedo, the amount of light the planet reflects.

The spacecraft will focus on exceptionally hot planets in our galaxy, with temperatures greater than 600 degrees Fahrenheit (320 degrees Celsius). Such planets are more likely to transit their star than planets orbiting farther out, and their short orbital periods provide more opportunities to observe transits in a given period of time. More transits give astronomers more data, allowing them to reveal the weak chemical fingerprint of a planet’s atmosphere.

ARIEL’s hot planet population will include gas giants like Jupiter, as well as smaller gaseous planets called mini-Neptunes and rocky worlds bigger than our planet called super-Earths. While these planets are too hot to host life as we know it, they will tell us a lot about how planets and planetary systems form and evolve. Additionally the techniques and insights learned in studying exoplanets with ARIEL and CASE will be useful when scientists use future telescopes to look toward smaller, colder, rockier worlds with conditions that more closely resemble Earth’s.

The CASE instrument consists of two detectors and associated electronics that contribute to ARIEL’s guidance system. CASE takes advantage of the same detectors and electronics that NASA is contributing to ESA’s Euclid mission, which will probe deep questions about the structure of the universe and its two biggest mystery components: dark matter and dark energy.

The ARIEL spacecraft with CASE on board will be in the same orbit as NASA’s James Webb Space Telescope, which is expected to launch in 2021. Both will travel some 1 million miles (1.5 million kilometers) from Earth to a special point of gravitational stability called Lagrange Point 2. This location allows the spacecraft to circle the Sun along with the Earth, while using little fuel to maintain its orbit.

While Webb will also be capable of studying exoplanet atmospheres, and its instruments cover a similar range of light as ARIEL, Webb will target a smaller sample of exoplanets to study in greater detail. Because Webb’s time will be divided, shared with investigations into other aspects of the universe, it will deliver detailed knowledge about particular exoplanets rather than surveying hundreds. ARIEL will launch several years after Webb, so it will be able to capitalize on lessons learned from Webb in terms of planning observations and selecting which planets to study.

“This is an exciting time for exoplanet science as we look toward the next generation of space telescopes and instruments,” said Paul Hertz, director of the astrophysics division at NASA Headquarters, Washington. “CASE adds to an exceptional set of technologies that will help us better understand our place in the galaxy.”

CASE is an Astrophysics Explorers Mission of Opportunity, managed by JPL. The Astrophysics Explorers Program is managed by NASA’s Goddard Space Flight Center in Greenbelt, Maryland, for the Science Mission Directorate at NASA Headquarters in Washington, DC.

See the full article here .


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Please help promote STEM in your local schools.

Stem Education Coalition

NASA JPL Campus

Jet Propulsion Laboratory (JPL)) is a federally funded research and development center and NASA field center located in the San Gabriel Valley area of Los Angeles County, California, United States. Although the facility has a Pasadena postal address, it is actually headquartered in the city of La Cañada Flintridge, on the northwest border of Pasadena. JPL is managed by the nearby California Institute of Technology (Caltech) for the National Aeronautics and Space Administration. The Laboratory’s primary function is the construction and operation of robotic planetary spacecraft, though it also conducts Earth-orbit and astronomy missions. It is also responsible for operating NASA’s Deep Space Network.

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From NASA JPL-Caltech: “Voyager 2 Illuminates Boundary of Interstellar Space”

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From NASA JPL-Caltech

November 4, 2019

Calla Cofield
Jet Propulsion Laboratory, Pasadena, Calif.
626-808-2469
calla.e.cofield@jpl.nasa.gov

1
An artist concept depicting one of NASA’s twin Voyager spacecraft. Humanity’s farthest and longest-lived spacecraft are celebrating 40 years in August and September 2017. This artist’s concept shows one of NASA’s Voyager spacecraft entering interstellar space, or the space between stars. This region is dominated by plasma ejected by the death of giant stars millions of years ago. Hotter, sparser plasma fills the environment inside our solar bubble.

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Two Interstellar Travelers. Annotated Image. This artist’s concept shows the locations of NASA’s Voyager 1 and Voyager 2 spacecraft relative to the heliosphere, or the protective bubble of particles and magnetic fields created by our Sun. Both Voyagers are now outside the heliosphere, in a region known as interstellar space, or the space between stars. Image Credit: NASA/JPL-Caltech

One year ago, on Nov. 5, 2018, NASA’s Voyager 2 became only the second spacecraft in history to leave the heliosphere – the protective bubble of particles and magnetic fields created by our Sun. At a distance of about 11 billion miles (18 billion kilometers) from Earth – well beyond the orbit of Pluto – Voyager 2 had entered interstellar space, or the region between stars. Today, five new research papers in the journal Nature Astronomy describe what scientists observed during and since Voyager 2’s historic crossing.

Magnetic field and particle measurements made by Voyager 2 at and near the heliopause

Plasma densities near and beyond the heliopause from the Voyager 1 and 2 plasma wave instruments

Voyager 2 plasma observations of the heliopause and interstellar medium

Energetic charged particle measurements from Voyager 2 at the heliopause and beyond

Cosmic ray measurements from Voyager 2 as it crossed into interstellar space

Each paper details the findings from one of Voyager 2’s five operating science instruments: a magnetic field sensor, two instruments to detect energetic particles in different energy ranges and two instruments for studying plasma (a gas composed of charged particles). Taken together, the findings help paint a picture of this cosmic shoreline, where the environment created by our Sun ends and the vast ocean of interstellar space begins.

The Sun’s heliosphere is like a ship sailing through interstellar space. Both the heliosphere and interstellar space are filled with plasma, a gas that has had some of its atoms stripped of their electrons. The plasma inside the heliosphere is hot and sparse, while the plasma in interstellar space is colder and denser. The space between stars also contains cosmic rays, or particles accelerated by exploding stars. Voyager 1 discovered that the heliosphere protects Earth and the other planets from more than 70% of that radiation.

When Voyager 2 exited the heliosphere last year, scientists announced that its two energetic particle detectors noticed dramatic changes: The rate of heliospheric particles detected by the instruments plummeted, while the rate of cosmic rays (which typically have higher energies than the heliospheric particles) increased dramatically and remained high. The changes confirmed that the probe had entered a new region of space.

Before Voyager 1 reached the edge of the heliosphere in 2012, scientists didn’t know exactly how far this boundary was from the Sun. The two probes exited the heliosphere at different locations and also at different times in the constantly repeating, approximately 11-year solar cycle, over the course of which the Sun goes through a period of high and low activity. Scientists expected that the edge of the heliosphere, called the heliopause, can move as the Sun’s activity changes, sort of like a lung expanding and contracting with breath. This was consistent with the fact that the two probes encountered the heliopause at different distances from the Sun.

The new papers now confirm that Voyager 2 is not yet in undisturbed interstellar space: Like its twin, Voyager 1, Voyager 2 appears to be in a perturbed transitional region just beyond the heliosphere.

“The Voyager probes are showing us how our Sun interacts with the stuff that fills most of the space between stars in the Milky Way galaxy,” said Ed Stone, project scientist for Voyager and a professor of physics at Caltech. “Without this new data from Voyager 2, we wouldn’t know if what we were seeing with Voyager 1 was characteristic of the entire heliosphere or specific just to the location and time when it crossed.”

Pushing Through Plasma

The two Voyager spacecraft have now confirmed that the plasma in local interstellar space is significantly denser than the plasma inside the heliosphere, as scientists expected. Voyager 2 has now also measured the temperature of the plasma in nearby interstellar space and confirmed it is colder than the plasma inside the heliosphere.

In 2012, Voyager 1 observed a slightly higher-than-expected plasma density just outside the heliosphere, indicating that the plasma is being somewhat compressed. Voyager 2 observed that the plasma outside the heliosphere is slightly warmer than expected, which could also indicate it is being compressed. (The plasma outside is still colder than the plasma inside.) Voyager 2 also observed a slight increase in plasma density just before it exited the heliosphere, indicating that the plasma is compressed around the inside edge of the bubble. But scientists don’t yet fully understand what is causing the compression on either side.

Leaking Particles

If the heliosphere is like a ship sailing through interstellar space, it appears the hull is somewhat leaky. One of Voyager’s particle instruments showed that a trickle of particles from inside the heliosphere is slipping through the boundary and into interstellar space. Voyager 1 exited close to the very “front” of the heliosphere, relative to the bubble’s movement through space. Voyager 2, on the other hand, is located closer to the flank, and this region appears to be more porous than the region where Voyager 1 is located.

Magnetic Field Mystery

An observation by Voyager 2’s magnetic field instrument confirms a surprising result from Voyager 1: The magnetic field in the region just beyond the heliopause is parallel to the magnetic field inside the heliosphere. With Voyager 1, scientists had only one sample of these magnetic fields and couldn’t say for sure whether the apparent alignment was characteristic of the entire exterior region or just a coincidence. Voyager 2’s magnetometer observations confirm the Voyager 1 finding and indicate that the two fields align, according to Stone.

The Voyager probes launched in 1978, and both flew by Jupiter and Saturn. Voyager 2 changed course at Saturn in order to fly by Uranus and Neptune, performing the only close flybys of those planets in history. The Voyager probes completed their Grand Tour of the planets and began their Interstellar Mission to reach the heliopause in 1989. Voyager 1, the faster of the two probes, is currently over 13.6 billion miles (22 billion kilometers) from the Sun, while Voyager 2 is 11.3 billion miles (18.2 billion kilometers) from the Sun. It takes light about 16.5 hours to travel from Voyager 2 to Earth. By comparison, light traveling from the Sun takes about eight minutes to reach Earth.

More information about Voyager is available at the following site:

https://voyager.jpl.nasa.gov/

See the full article here .


five-ways-keep-your-child-safe-school-shootings

Please help promote STEM in your local schools.

Stem Education Coalition

NASA JPL Campus

Jet Propulsion Laboratory (JPL)) is a federally funded research and development center and NASA field center located in the San Gabriel Valley area of Los Angeles County, California, United States. Although the facility has a Pasadena postal address, it is actually headquartered in the city of La Cañada Flintridge, on the northwest border of Pasadena. JPL is managed by the nearby California Institute of Technology (Caltech) for the National Aeronautics and Space Administration. The Laboratory’s primary function is the construction and operation of robotic planetary spacecraft, though it also conducts Earth-orbit and astronomy missions. It is also responsible for operating NASA’s Deep Space Network.

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From NASA JPL-Caltech: Women in STEM- “A Young Engineer Steps Into the Light” Janelle Wellons

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From NASA JPL-Caltech

1
Janelle Wellons works as an engineer operating the Lunar Reconnaissance Orbiter’s Diviner instrument.Credit: Joshua Krohn

November 1, 2019

Matthew Segal
Jet Propulsion Laboratory, Pasadena, Calif.
818-354-8307
matthew.j.segal@jpl.nasa.gov

Written by Celeste Hoang

In high school, Janelle Wellons excelled in her classes, especially math, and quickly climbed to the top of her class. By the spring of her senior year, she had an acceptance letter in hand from her dream school, the Massachusetts Institute of Technology. But while that should have been a joyous time, an incident with a high school classmate cast a long shadow.

“One of my classmates approached me in front of a group of friends and said, ‘We all know the reason you got accepted into MIT is because you’re black,'” Wellons recalled. “No one standing there said anything, and the fact that no one stood up for me spoke volumes.”

Today, Wellons shows no hint of how close she came to giving up – not because of the sting of one comment that broke the surface, but because of the doubts and questions that worked invisibly during her formative years.

Bright-eyed with an ebullient personality and hearty laugh, she works as an engineer at NASA’s Jet Propulsion Laboratory in Pasadena, California, where she operates the Lunar Reconnaissance Orbiter’s Diviner instrument – a radiometer that measures the surface temperature of the Moon. Wellons is also developing the system that will command the Multi-Angle Imager for Aerosols instrument, which will launch around 2022 to study how Earth’s pollutants affect people’s health on a global scale.

Just three years out of college, she is one of the youngest staffers on a Moon mission and an Earth mission. But while her progress has been quick, it was not easy.

A Gray Summit

Wellons grew up in South Jersey, the eldest of two siblings. Her mother was a secretary at an oil and gas corporation, and her father worked in warehouses. When she was about 6 years old, she went with her mother on a bring-your-child-to-work day and spent the morning surrounded by engineers doing demonstrations for the kids.

“It opened my eyes to realize: an engineer makes things!” she said. “I got that into my mind.”

But as she grew older, Wellons realized that reaching her goals would sometimes come alongside prejudice. The acceptance-letter incident wasn’t her only brush with racism. Wellons felt racial tension throughout her high school years, especially since she was often one of the few black students in her advanced placement classes.

“It kind of defined me. It was like they couldn’t see anything else,” she says. “In high school, people joke about bad things all the time and they always say they were kidding to make it OK, but after a time, it gets to you,” she says.

By her senior year, she recalled, “Something was just not right.”

It wasn’t feeling hurt that alarmed her. It was feeling nothing at all.

The spring of her senior year, Wellons received a call from the MIT Office of Engineering Outreach Programs with the news that she’d been awarded a scholarship.

“It should’ve been a very happy moment, but I didn’t feel anything and just hung up the phone and sat outside by the lockers,” she recalled. “When I realized I couldn’t feel happy about that, I realized there was something really wrong with me.

“That’s when the suicidal thoughts started to creep in, like, ‘Why can’t I have authentic reactions anymore?’ I knew it was a serious problem.”

Shedding the Label

Wellons’ parents sought out a therapist to help her, and as she entered MIT, things dramatically improved. She joined a black student union, pledged a sorority and interacted with a multicultural community on campus.

“I definitely had a huge transformation in college,” she says. “When you take away the ‘smart black girl’ label, you become your own person and people can have a conversation beyond that.”

Still, her course load was demanding, and Wellons quickly realized she was, as she says, “in another realm of smart,” finding herself sitting next to a gold medal winner of the International Math Olympiad and doubting why she was admitted to MIT. “But that was a good thing.”

Although she thought she might major in mathematics, an aerospace engineering class changed her mind. The professor showed a photo of an astronaut fixing NASA’s Hubble Space Telescope and revealed that he was the person in the photo. Wellons was in awe.

“The opportunity to be taught by an astronaut was something I could not pass up,” she said. “I realized that’s what I wanted to do – I’m going to learn about space from experts! I was blown away by that.”

Another professor introduced her to the value of critical self-assessment during a capstone project involving an Antarctic penetrator probe. “He was a really tough professor who would angrily say, ‘This would never pass a review in the industry,’ and would heavily criticize our presentations,” she recalled. “But my standards are much higher now because of him, and I’m just as nitpicky.”

Real-time Engineer

Wellons applies that work ethic around the clock at JPL. She’s on call 24/7 for the Diviner instrument Reconnaissance Orbiter, sometimes getting calls at 2 a.m. and, on one rare occasion, had to rush to her laptop in the middle of a night out with friends.

“The one scary thing is, you are the engineer responsible for the instrument’s success,” she said. “You are the operator, and you can’t afford to be sloppy in this job. Instruments don’t sleep.”

Wellons’ typical day starts with checking on the health and safety of her instrument or, as she puts it, “making sure it’s alive and well.” Then she’ll work with the science team and, depending on what they would like to look at, help figure out if their requests can be met without putting the instrument’s well-being at risk.

“You’re in charge of making sure the scientists don’t push the limit,” she explained. “If you get too greedy, you might break the instrument.”

Then she creates the commands that will be sent to the instrument.

Community Builder

At JPL, Wellons balances gratitude for her career and awareness that being a black female engineer comes with challenges.

“I am so thankful to be here, because growing up, I rarely if ever saw someone who looks like me working at a company so incredibly amazing, making history every day,” she said. “At the same time, that doesn’t mean [there aren’t] comments toward me. JPL is made up of individuals with their own thoughts and experiences and perspectives on life, so of course you’re going to have instances. It’s definitely not going to slow me down, though.”

To help spread the message of inclusion, Wellons is on the board of JPL’s African American Resource Team, which she’s helping revitalize.

“It’s about building a cultural community and encouraging other young people to come work here,” she says.

While Wellons often has work on the brain, she also carves out time to give back.

Last summer, she spent two weeks in South Korea, helping third- through sixth-graders at space camp learn about extraterrestrial volcanic bodies, launch bottle rockets and simulate rover driving.

Looking back on what she’s been through, Wellons remains focused on positivity and making the most of her time at JPL – seeking out mentors, gaining a wide variety of experiences and setting her sights on making her voice and her vision heard.

“Being here a short time doesn’t mean that you can’t accomplish great things quickly,” she said. But not easily, in her experience, and not without the right people on your side along the way.

“I am immensely thankful for the opportunities and support that have brought me to JPL, because it was never a straight shot,” Wellons said. “Don’t forget those who have supported you, believed in you, prayed for you, taught you and lifted you up when you felt especially down.”

See the full article here .


five-ways-keep-your-child-safe-school-shootings

Please help promote STEM in your local schools.

Stem Education Coalition

NASA JPL Campus

Jet Propulsion Laboratory (JPL)) is a federally funded research and development center and NASA field center located in the San Gabriel Valley area of Los Angeles County, California, United States. Although the facility has a Pasadena postal address, it is actually headquartered in the city of La Cañada Flintridge, on the northwest border of Pasadena. JPL is managed by the nearby California Institute of Technology (Caltech) for the National Aeronautics and Space Administration. The Laboratory’s primary function is the construction and operation of robotic planetary spacecraft, though it also conducts Earth-orbit and astronomy missions. It is also responsible for operating NASA’s Deep Space Network.

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From NASA JPL-Caltech: “Mars 2020 Unwrapped and Ready for Testing”

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From NASA JPL-Caltech

October 18, 2019

DC Agle
Jet Propulsion Laboratory, Pasadena, Calif.
818-393-9011
agle@jpl.nasa.gov

Alana Johnson
NASA Headquarters, Washington
202-672-4780
alana.r.johnson@nasa.gov

NASA Mars 2020 rover schematic

NASA Mars 2020 Rover

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Bunny-suited engineers remove the inner layer of protective foil on NASA’s Mars 2020 rover after it was moved to a different building at JPL for testing.

“The Mars 2020 rover will be collecting samples for future return to Earth, so it must meet extraordinary cleanliness measures to avoid the possibility of contaminating Martian samples with terrestrial contaminants,” said Paul Boeder, contamination control lead for Mars 2020 at JPL. “To ensure we maintain cleanliness at all times, we need to keep things clean not only during assembly and testing, but also during the moves between buildings for these activities.”

After removing the first layer of antistatic foil, the teams used 70% isopropyl alcohol to meticulously wipe down the remaining layer, seen here, along with the trailer carrying the rover. Later that day, the rover was moved into the larger main room of the Simulator Building. In the coming weeks, the rover will enter a massive vacuum chamber for surface thermal testing – a weeklong evaluation of how its instruments, systems and subsystems operate in the frigid, near-vacuum environment it will face on Mars.

JPL is building and will manage operations of the Mars 2020 rover for NASA. The rover will launch on a United Launch Alliance Atlas V rocket in July 2020 from Space Launch Complex 41 at Cape Canaveral Air Force Station. NASA’s Launch Services Program, based at the agency’s Kennedy Space Center in Florida, is responsible for launch management.

When the rover lands at Jezero Crater on Feb. 18, 2021, it will be the first spacecraft in the history of planetary exploration with the ability to accurately retarget its point of touchdown during the landing sequence.

Charged with returning astronauts to the Moon by 2024, NASA’s Artemis lunar exploration plans will establish a sustained human presence on and around the Moon by 2028. We will use what we learn on the Moon to prepare to send astronauts to Mars.

Interested K-12 students in U.S. public, private and home schools can enter the Mars 2020 Name the Rover essay contest. One grand prize winner will name the rover.

For more information about the name contest, go to:

https://mars.nasa.gov/mars2020/participate/name-the-rover/

For more information about the mission, go to:
https://mars.nasa.gov/mars2020/

See the full article here .


five-ways-keep-your-child-safe-school-shootings

Please help promote STEM in your local schools.

Stem Education Coalition

NASA JPL Campus

Jet Propulsion Laboratory (JPL)) is a federally funded research and development center and NASA field center located in the San Gabriel Valley area of Los Angeles County, California, United States. Although the facility has a Pasadena postal address, it is actually headquartered in the city of La Cañada Flintridge, on the northwest border of Pasadena. JPL is managed by the nearby California Institute of Technology (Caltech) for the National Aeronautics and Space Administration. The Laboratory’s primary function is the construction and operation of robotic planetary spacecraft, though it also conducts Earth-orbit and astronomy missions. It is also responsible for operating NASA’s Deep Space Network.

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#astronomy, #astrophysics, #basic-research, #cosmology, #nasa-jpl-caltech, #nasa-mars-2020-rover, #nasa-must-meet-extraordinary-cleanliness-measures-to-avoid-the-possibility-of-contaminating-martian-samples-with-terrestrial-contaminants

From NASA JPL-Caltech: “Caltech, NASA Find Web of Ruptures in Ridgequest Quake”

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From NASA JPL-Caltech

October 17, 2019

Esprit Smith
Jet Propulsion Laboratory, Pasadena, Calif.
818-354-4269
esprit.smith@jpl.nasa.gov

Robert Perkins
Caltech, Pasadena, Calif.
626-395-1862
rperkins@caltech.edu

1
A USGS Earthquake Science Center Mobile Laser Scanning truck scans the surface rupture near the zone of maximum surface displacement of the magnitude 7.1 earthquake that struck the Ridgecrest area. Credit: USGS / Ben Brooks

A new study of Southern California’s largest earthquake sequence in two decades provides new evidence that large earthquakes can occur in a more complex fashion than commonly assumed. The analysis by geophysicists from Caltech and NASA’s Jet Propulsion Laboratory, both in Pasadena, California, documents a series of ruptures in a web of interconnected faults, with rupturing faults triggering other faults.

The dominoes-like sequence of ruptures also increased strain on a nearby major fault, according to the study, which was published today in the journal Science.

The Ridgecrest Earthquake Sequence began with a magnitude 6.4 foreshock on July 4, 2019, followed by a magnitude 7.1 mainshock the next day with more than 100,000 aftershocks. The sequence rattled most of Southern California, but the strongest shaking occurred about 120 miles (190 kilometers) north of Los Angeles near the town of Ridgecrest.

“This ended up being one of the best-documented earthquake sequences in history,” said Zachary Ross, assistant professor of geophysics at Caltech and lead author of the Science paper. Ross developed an automated computer analysis of seismometer data that detected the enormous number of aftershocks with highly precise location information, and the JPL team members analyzed data from international radar satellites ALOS-2 (from the Japan Aerospace Exploration Agency, or JAXA) and Sentinel-1A/B (operated by the European Space Agency, or ESA) to map fault ruptures at Earth’s surface.

JAXA ALOS-2 satellite aka DAICH-2

ESA Sentinel-1B

“I was surprised to see how much complexity there was and the number of faults that ruptured,” said JPL co-author Eric Fielding.

The satellite and seismometer data together depict an earthquake sequence that is far more complex than those found in the models of many previous large seismic events. Major earthquakes are commonly thought to be caused by the rupture of a single long fault, such as the more than 800-mile-long (1,300-kilometer-long) San Andreas fault, with the maximum possible magnitude dictated primarily by the length of the fault. After a large 1992 earthquake in Landers, California, ruptured several faults, seismologists began rethinking that model.

The Ridgecrest sequence involved about 20 previously undiscovered, smaller faults crisscrossing in a geometrically complex and geologically young fault zone.

“We actually see that the magnitude 6.4 quake simultaneously broke faults at right angles to each other, which is surprising because standard models of rock friction view this as unlikely,” Ross said.

2
All earthquakes of magnitude 2.5 and greater in the Ridgecrest area July 4 to Aug. 15, 2019, are shown as gray circles. Red stars mark the two largest. The Garlock Fault south of the cluster of earthquakes has slipped almost an inch since July. Credit: USGS

The complexity of the event is only clear because of the multiple types of scientific instruments used to study it. Satellites observed the surface ruptures and associated ground deformation extending out over 60 miles (100 kilometers) in every direction from the rupture, while a dense network of seismometers observed the seismic waves that radiated from the earthquake. Together, these data allowed scientists to develop a model of how the faults slipped below the surface and the relationship between the major slipping faults and the significant number of small earthquakes occurring before, between and after the two largest shocks.

The Ridgecrest ruptures ended just a few miles shy of the Garlock Fault, a major east-west fault running more than 185 miles (300 kilometers) from the San Andreas Fault to Death Valley. The fault has been relatively quiet for the past 500 years, but the strain placed on the Garlock Fault by July’s earthquake activity triggered it to start slowly moving, a process call fault creep. The fault has slipped 0.8 inches (2 centimeters) at the surface since July, the scientists said.

The event illustrates how little we still understand about earthquakes. “It’s going to force people to think hard about how we quantify seismic hazard and whether our approach to defining faults needs to change,” Ross said. “We can’t just assume that the largest faults dominate the seismic hazard if many smaller faults can link up to create these major quakes.”

See the full article here .


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Please help promote STEM in your local schools.

Stem Education Coalition

NASA JPL Campus

Jet Propulsion Laboratory (JPL)) is a federally funded research and development center and NASA field center located in the San Gabriel Valley area of Los Angeles County, California, United States. Although the facility has a Pasadena postal address, it is actually headquartered in the city of La Cañada Flintridge, on the northwest border of Pasadena. JPL is managed by the nearby California Institute of Technology (Caltech) for the National Aeronautics and Space Administration. The Laboratory’s primary function is the construction and operation of robotic planetary spacecraft, though it also conducts Earth-orbit and astronomy missions. It is also responsible for operating NASA’s Deep Space Network.

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#a-dense-network-of-seismometers-observed-the-seismic-waves-that-radiated-from-the-earthquake, #caltech, #magnitude-6-4-foreshock-on-july-4-2019, #magnitude-7-1-mainshock-july-5-2019, #nasa-find-web-of-ruptures-in-ridgequest-quake, #nasa-jpl-caltech, #ridgecrest-earthquake-sequence, #satellites-observed-the-surface-ruptures-and-associated-ground-deformation-extending-out-over-60-miles-100-kilometers-in-every-direction-from-the-rupture, #southern-californias-largest-earthquake-sequence-in-two-decades, #the-complexity-of-the-event-is-only-clear-because-of-the-multiple-types-of-scientific-instruments-used-to-study-it, #the-event-illustrates-how-little-we-still-understand-about-earthquakes, #the-ridgecrest-ruptures-ended-just-a-few-miles-shy-of-the-garlock-fault-a-major-east-west-fault-running-more-than-185-miles-300-kilometers-from-the-san-andreas-fault-to-death-valley, #the-ridgecrest-sequence-involved-about-20-previously-undiscovered-smaller-faults-crisscrossing-in-a-geometrically-complex-and-geologically-young-fault-zone

From NASA JPL-Caltech: “NASA’s Curiosity Rover Finds an Ancient Oasis on Mars”

From NASA JPL-Caltech

October 7, 2019

Andrew Good
Jet Propulsion Laboratory, Pasadena, Calif.
818-393-2433
andrew.c.good@jpl.nasa.gov

Alana Johnson
NASA Headquarters, Washington
202-358-1501
alana.r.johnson@nasa.gov

1
The network of cracks in this Martian rock slab called “Old Soaker” may have formed from the drying of a mud layer more than 3 billion years ago. The view spans about 3 feet (90 centimeters) left-to-right and combines three images taken by the MAHLI camera on the arm of NASA’s Curiosity Mars rover. Credit: NASA/JPL-Caltech/MSSS

If you could travel back in time 3.5 billion years, what would Mars look like? The picture is evolving among scientists working with NASA’s Curiosity rover.

Imagine ponds dotting the floor of Gale Crater, the 100-mile-wide (150-kilometer-wide) ancient basin that Curiosity is exploring. Streams might have laced the crater’s walls, running toward its base. Watch history in fast forward, and you’d see these waterways overflow then dry up, a cycle that probably repeated itself numerous times over millions of years.

That is the landscape described by Curiosity scientists in a Nature Geoscience paper published today. The authors interpret rocks enriched in mineral salts discovered by the rover as evidence of shallow briny ponds that went through episodes of overflow and drying. The deposits serve as a watermark created by climate fluctuations as the Martian environment transitioned from a wetter one to the freezing desert it is today.

Scientists would like to understand how long this transition took and when exactly it occurred. This latest clue may be a sign of findings to come as Curiosity heads toward a region called the “sulfate-bearing unit,” which is expected to have formed in an even drier environment. It represents a stark difference from lower down the mountain, where Curiosity discovered evidence of persistent freshwater lakes.

Gale Crater is the ancient remnant of a massive impact. Sediment carried by water and wind eventually filled in the crater floor, layer by layer. After the sediment hardened, wind carved the layered rock into the towering Mount Sharp, which Curiosity is climbing today. Now exposed on the mountain’s slopes, each layer reveals a different era of Martian history and holds clues about the prevailing environment at the time.

“We went to Gale Crater because it preserves this unique record of a changing Mars,” said lead author William Rapin of Caltech. “Understanding when and how the planet’s climate started evolving is a piece of another puzzle: When and how long was Mars capable of supporting microbial life at the surface?”

He and his co-authors describe salts found across a 500-foot-tall (150-meter-tall) section of sedimentary rocks called “Sutton Island,” which Curiosity visited in 2017. Based on a series of mud cracks at a location named “Old Soaker,” the team already knew the area had intermittent drier periods. But the Sutton Island salts suggest the water also concentrated into brine.

Typically, when a lake dries up entirely, it leaves piles of pure salt crystals behind. But the Sutton Island salts are different: For one thing, they’re mineral salts, not table salt. They’re also mixed with sediment, suggesting they crystallized in a wet environment – possibly just beneath evaporating shallow ponds filled with briny water.

Given that Earth and Mars were similar in their early days, Rapin speculated that Sutton Island might have resembled saline lakes on South America’s Altiplano. Streams and rivers flowing from mountain ranges into this arid, high-altitude plateau lead to closed basins similar to Mars’ ancient Gale Crater. Lakes on the Altiplano are heavily influenced by climate in the same way as Gale.

“During drier periods, the Altiplano lakes become shallower, and some can dry out completely,” Rapin said. “The fact that they’re vegetation-free even makes them look a little like Mars.”

Signs of a Drying Mars

Sutton Island’s salt-enriched rocks are just one clue among several the rover team is using to piece together how the Martian climate changed. Looking across the entirety of Curiosity’s journey, which began in 2012, the science team sees a cycle of wet to dry across long timescales on Mars.

“As we climb Mount Sharp, we see an overall trend from a wet landscape to a drier one,” said Curiosity Project Scientist Ashwin Vasavada of NASA’s Jet Propulsion Laboratory in Pasadena, California. JPL leads the Mars Science Laboratory mission that Curiosity is a part of. “But that trend didn’t necessarily occur in a linear fashion. More likely, it was messy, including drier periods, like what we’re seeing at Sutton Island, followed by wetter periods, like what we’re seeing in the ‘clay-bearing unit’ that Curiosity is exploring today.”

Up until now, the rover has encountered lots of flat sediment layers that had been gently deposited at the bottom of a lake. Team member Chris Fedo, who specializes in the study of sedimentary layers at the University of Tennessee, noted that Curiosity is currently running across large rock structures that could have formed only in a higher-energy environment such as a windswept area or flowing streams.

Wind or flowing water piles sediment into layers that gradually incline. When they harden into rock, they become large structures similar to “Teal Ridge,” which Curiosity investigated this past summer.

“Finding inclined layers represents a major change, where the landscape isn’t completely underwater anymore,” said Fedo. “We may have left the era of deep lakes behind.”

Curiosity has already spied more inclined layers in the distant sulfate-bearing unit. The science team plans to drive there in the next couple years and investigate its many rock structures. If they formed in drier conditions that persisted for a long period, that might mean that the clay-bearing unit represents an in-between stage – a gateway to a different era in Gale Crater’s watery history.

“We can’t say whether we’re seeing wind or river deposits yet in the clay-bearing unit, but we’re comfortable saying is it’s definitely not the same thing as what came before or what lies ahead,” Fedo said.

For more about NASA’s Curiosity Mars rover mission, visit:

https://mars.nasa.gov/msl/

https://nasa.gov/msl

See the full article here .

five-ways-keep-your-child-safe-school-shootings

Please help promote STEM in your local schools.

Stem Education Coalition

NASA JPL Campus

Jet Propulsion Laboratory (JPL) is a federally funded research and development center and NASA field center located in the San Gabriel Valley area of Los Angeles County, California, United States. Although the facility has a Pasadena postal address, it is actually headquartered in the city of La Cañada Flintridge [1], on the northwest border of Pasadena. JPL is managed by the nearby California Institute of Technology (Caltech) for the National Aeronautics and Space Administration. The Laboratory’s primary function is the construction and operation of robotic planetary spacecraft, though it also conducts Earth-orbit and astronomy missions. It is also responsible for operating NASA’s Deep Space Network.

#nasas-curiosity-rover-finds-an-ancient-oasis-on-mars, #gale-crater, #mars-research, #nasa-jpl-caltech