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STScI Astronomer Margaret Meixner Elected AAAS Fellow
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By NASA
On Jan. 7, 1610, Italian astronomer Galileo Galilei peered through his newly improved 20-power homemade telescope at the planet Jupiter. He noticed three other points of light near the planet, at first believing them to be distant stars. Observing them over several nights, he noted that they appeared to move in the wrong direction with regard to the background stars and they remained in Jupiter’s proximity but changed their positions relative to one another. Four days later, he observed a fourth point of light near the planet with the same unusual behavior. By Jan. 15, Galileo correctly concluded that he had discovered four moons orbiting around Jupiter, providing strong evidence for the Copernican theory that most celestial objects did not revolve around the Earth.
Two of Galileo’s telescopes.National Geographic. Painting by Giuseppe Bertini (1858) of Galileo demonstrating his telescope to the Doge of Venice.gabrielevanin.it Page from Galileo’s notebook about his observations of Jupiter’s satellites.University of Michigan Special Collections Library. In March 1610, Galileo published his discoveries of Jupiter’s satellites and other celestial observations in a book titled Siderius Nuncius (The Starry Messenger). As their discoverer, Galileo had naming rights to Jupiter’s satellites. He proposed to name them after his patrons the Medicis and astronomers called them the Medicean Stars through much of the seventeenth century, although in his own notes Galileo referred to them by the Roman numerals I, II, III, and IV, in order of their distance from Jupiter. Astronomers still refer to the four moons as the Galilean satellites in honor of their discoverer.
In 1614, the German astronomer Johannes Kepler suggested naming the satellites after mythological figures associated with Jupiter, namely Io, Europa, Ganymede, and Callisto, but his idea didn’t catch on for more than 200 years. Scientists didn’t discover any more satellites around Jupiter until 1892 when American astronomer E.E. Barnard found Jupiter’s fifth moon Amalthea, much smaller than the Galilean moons and orbiting closer to the planet than Io. It was the last satellite in the solar system found by visual observation – all subsequent discoveries occurred via photography or digital imaging. As of today, astronomers have identified 95 moons orbiting Jupiter.
Image of Jupiter and three of its four Galilean satellites through an amateur telescope, similar to what Galileo might have seen. Hubble Space Telescope image of Jupiter and three of its four Galilean satellites during a rare triple transit. Although each of the Galilean satellites has unique features, such as the volcanoes of Io, the heavily cratered surface of Callisto, and the magnetic field of Ganymede, scientists have focused more attention on Europa due to the tantalizing possibility that it might be hospitable to life. In the 1970s, NASA’s Pioneer 10 and 11 and Voyager 1 and 2 spacecraft took ever increasingly detailed images of the large satellites including Europa during their flybys of Jupiter. The photographs revealed Europa to have the smoothest surface of any object in the solar system, indicating a relatively young crust, and also one of the brightest of any satellite indicating a highly reflective surface. These features led scientists to hypothesize that Europa is covered by an icy crust floating on a subsurface salty ocean. They further postulated that tidal heating caused by Jupiter’s gravity reforms the surface ice layer in cycles of melting and freezing.
Image of Europa taken by Pioneer 10 during its flyby of Jupiter in 1973. Image of Europa taken by Voyager 1 during its 1979 flyby of Jupiter. Image of Europa taken by Voyager 2 during its 1979 flyby of Jupiter. More detailed observations from NASA’s Galileo spacecraft that orbited Jupiter between 1995 and 2003 and completed 11 close encounters with Europa revealed that long linear features on its surface may indicate tidal or tectonic activity. Reddish-brown material along the fissures and in splotches elsewhere on the surface may contain salts and sulfur compounds transported from below the crust and modified by radiation. Observations from the Hubble Space Telescope and re-analysis of images from Galileo revealed possible plumes emanating from beneath Europa’s crust, lending credence to that hypothesis. While the exact composition of this material is not known, it likely holds clues to whether Europa may be hospitable to life.
Global view of Europa from the Galileo spacecraft. More detailed views of varied terrain on Europa from Galileo. Cutaway illustration of Europa’s icy crust, subsurface ocean and possible vents that transport material to the surface. Future robotic explorers of Europa may answer some of the outstanding questions about this unique satellite of Jupiter. NASA’s Europa Clipper set off in October 2024 on a 5.5-year journey to Jupiter. After its arrival in 2030, the spacecraft will enter orbit around the giant planet and conduct 49 flybys of Europa during its four-year mission. Managed by the Jet Propulsion Laboratory in Pasadena, California, and the Applied Physics Laboratory at Johns Hopkins University in Baltimore, Maryland, Europa Clipper will carry nine instruments including imaging systems and a radar to better understand the structure of the icy crust. Data from Europa Clipper will complement information returned by the European Space Agency’s JUICE (Jupiter Icy Moon Explorer) spacecraft. Launched in April 2023, JUICE will first enter orbit around Jupiter in 2031 and then enter orbit around Ganymede in 2034. The spacecraft also plans to conduct studies of Europa complementary with Europa Clipper’s. The two spacecraft should greatly increase our understanding of Europa and perhaps uncover new mysteries.
Illustration of the Europa Clipper spacecraft investigating Europa. Illustration of the JUICE spacecraft exploring Europa.European Space Agency. View the full article
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By NASA
1 min read
Preparations for Next Moonwalk Simulations Underway (and Underwater)
Dr. Misty Davies receives the prestigious AIAA Fellowship in May 2024 for her contributions to aerospace safety and autonomous systems, recognized at a ceremony in Washington, DC.NASA In May 2024, Dr. Misty Davies joined the American Institute of Aeronautics and Astronautics (AIAA) Class of 2024 Fellows at a ceremony in Washington, DC. The AIAA website states that, “AIAA confers Fellow upon individuals in recognition of their notable and valuable contributions to the arts, sciences or technology of aeronautics and astronautics.” The first AIAA Fellows were elected in 1934; since then only 2064 people have been selected for the honor. Dr. Davies has focused her career at NASA Ames Research Center on developing tools and techniques that enable the safety assurance of increasingly autonomous systems. She currently serves as the Associate Chief for Aeronautics Systems in the Intelligent Systems Division at NASA Ames and is the Aerospace Operations and Safety Program (AOSP) Technical Advisor for Assurance and Safety. More information on AIAA Fellows is at https://www.aiaa.org/news/news/2024/02/08/aiaa-announces-class-of-2024-honorary-fellows-and-fellows
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Last Updated Nov 22, 2024 Related Terms
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By NASA
In August, the Association for Advancing Participatory Sciences (AAPS) announced a fellowship opportunity in partnership with the NASA Citizen Science Leaders Series. Fifty-five people applied! The applications came from graduate students and early career professionals in diverse disciplines, including astronomy, ecology, engineering, nursing, policy, and zoology, to name a few.
Sadie Coffin, AAPS-NASA Cit Sci Leaders Fellow. (Credit: Olivia Schlichtkrull)
We are delighted to announce that Sadie Coffin, PhD student and co-lead (alongside her advisor, Dr. Jeyhan Kartaltepe) of the Redshift Wrangler project, will serve as the AAPS-NASA Cit Sci Leaders Fellow. Sadie’s task is to curate resources, advice, and best practices on topics of common interest from four years of NASA Cit Sci Leaders events. Sadie will dig into our recordings to find the moments, speakers, advice, and resources that offer the best guidance for project leaders starting or managing projects. She’ll help package the best elements of the recordings into usable formats for busy scientists and project leaders interested in creating, managing, and improving participatory science projects.
“This fellowship offers a unique opportunity to gain the mentorship and expertise I need to build a career that not only advances research but also fosters public engagement and inclusivity in science,” said Sadie.
The enthusiasm, talent, and passion in the applications we received revealed the broad appeal, utility, and growing acceptance of participatory research. One applicant commented, “Working in the participatory sciences is how I find meaning in my career as a researcher.” Many others commented that they were eager to connect with mentors and colleagues who were as invested in this work as they were.
Thank you to everyone who applied for this fellowship and to all of the early career professionals working in this field. You are inspiring, and we can’t wait to see what big ideas you contribute to the growth of this field! AAPS will announce additional fellowships focused on different projects in the coming months. Please watch for upcoming calls, consider applying yourself, and share them with the inspiring early career individuals in your networks!
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Last Updated Nov 04, 2024 Related Terms
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By NASA
In October 1604, a new star appeared in the sky, puzzling astronomers of the day. First observed on Oct. 9, German astronomer Johannes Kepler (1571-1630) began his observations on Oct. 17 and tracked the new star for over a year. During that time, it brightened to magnitude -2.5, outshining Jupiter, and for several weeks remained visible in the daytime. Publication of his detailed observations in 1606 led astronomers to call the star Kepler’s Supernova, today formally designated as supernova SN 1604. Astronomers of the day did not know what caused the star’s sudden appearance and eventual disappearance, but the phenomenon helped shape European cosmology toward the heliocentric model proposed by Polish astronomer Nicolaus Copernicus half a century earlier. Today, astronomers designate SN 1604 as a Type Ia supernova, resulting from the explosion of a white dwarf star, and use ground-based and space-based telescopes to study its remnants.
Left: Portrait of Johannes Kepler by August Köhler. Middle: Kepler’s book about his observations of the 1604 supernova open to the page depicting the location of the new star. Right: Closeup of Kepler’s illustration of the location of the new star, designated N, in the constellation Ophiuchus near the right foot of the serpent-bearer.
Italian astronomer Lodovico delle Colombo first observed the supernova in the constellation Ophiuchus on Oct. 9. Kepler, then working in Prague, heard rumors of the new star but did not observe it until Oct. 17. He continued to monitor the star for over a year, inspired by the earlier work of Danish astronomer Tycho Brahe’s observations of a similar phenomenon, the 1572 supernova. The new star quickly brightened to magnitude -2.5, outshining Jupiter, and for three weeks could be seen in the daytime before finally fading into obscurity in March 1606. Kepler could only make naked eye observations, since Italian astronomer Galileo Galilei didn’t turn his newly invented telescope to the skies for another four years after SN 1604 faded from view.
Later in 1606, Kepler summarized his observations in his book De Stella nova in pede Serpentarii (On the New Star in Ophiuchus’ Foot), published in Prague. SN 1604 is believed to be about 20,000 light years away, near the edge of a dark nebula complex. Kepler and his contemporaries observed not only the last known supernova to occur in the Milky Way Galaxy but also the last supernova visible to the naked eye until 1987. That one, Supernova 1987A, appeared in the Large Magellanic Cloud, a small satellite galaxy of the Milky Way.
A Type Ia supernova results from a white dwarf drawing in material from a nearby red giant star, the additional mass leading to a runaway thermonuclear explosion.
Astronomers today understand that what Kepler and others believed as the birth of a new star actually represented the violent death of a star. Astronomers today classify supernovas according to their characteristics, and SN 1604 belongs to the group known as Type Ia supernovas, typically found in binary star systems composed of a white dwarf and a red giant. The gravitation force of the white dwarf draws in material from its larger less dense companion until it reaches a critical mass, around 1.4 times the mass of our Sun. At that point, a runaway thermonuclear chain reaction begins, causing a release of tremendous amounts of energy, including light, that we see as a sudden brightening of an otherwise dim star.
Images of Kepler’s supernova remnants in different portions of the electromagnetic spectrum. Left: X-ray image from the Chandra X-ray Observatory. Middle: Visible image from the Hubble Space Telescope. Right: Infrared image from the Spitzer Space Telescope.
Supernova explosions leave remnants behind and those of SN 1604 remain visible today. Ground-based and space-based instruments using different parts of the electromagnetic spectrum study these remnants to gain a better understanding of their origins. The remnants of SN 1604 emit energy most strongly in the radio and X-ray parts of the electromagnetic spectrum. In recent years, astronomers have used Type Ia supernovas to determine the rate of expansion of the universe. Because Type Ia supernovas all occur in stars of about 1.4 solar masses, they give out about the same amount of light. This makes them useful as distance indicators – if one Type Ia supernova is dimmer than another one, it is further away by an amount that astronomers can calculate. Based on this information, astronomers believe that the expansion of the universe is accelerating, possibly caused by the presence of a mysterious substance called dark energy.
Events in world history in 1604:
January 1 – First performance of William Shakespeare’s play A Midsummer’s Night’s Dream.
March 22 – Karl IX begins his rule as King of Sweden.
August 5 – Sokolluzade Mehmed Pasha becomes the new Ottoman Grand Vizier in Constantinople.
August 18 – England and Spain sign the Treaty of London, ending their 20-year war.
September 1 – Sri Guru Granth Sahib, Sikhism’s religious text, is installed at Hamandir Sahib in Amritsar, India.
October 4 – Emperor of Ethiopia Za Dengel is killed in battle with the forces of Za Sellase, who restores his cousin Yaqob to the throne.
November 1 – First performance of William Shakespeare’s tragedy Othello.
December 29 – A magnitude 8.1 earthquake shakes the Taiwan Strait causing significant damage.
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By NASA
Although surrounded by the big and bold missions of human spaceflight, Margaret Kennedy, an aerospace systems engineer on the Human Health and Performance Contract, still appreciates the little things. Ask about her favorite NASA experience to date and she will tell you it is getting to show her badge to the gate guards at Houston’s Johnson Space Center every day. “Knowing I get to be a part of things that can change the world – that I’m helping to make it possible for astronauts to do their job safely, which in turn supports life on Earth – is very rewarding,” she said.
Margaret Kennedy poses with Johnson Space Center’s inflatable mascot, Cosmo, at Comicpalooza 2024 in Houston, Texas. Image courtesy of Margaret Kennedy Kennedy joined the Johnson team as a contractor with Aegis Aerospace in October 2019. Since then, she has spent most of her time as a systems engineer for the Human Research Program’s Program Integration and Strategic Planning group. That role required her to collect technical information for various projects and to ensure systems were in place to correctly track and manage program documents and agreements. This spring, Kennedy transitioned to a new role in which she provides systems engineering for flight hardware supporting Gateway and exploration missions to the Moon and Mars.
She started engaging with Johnson’s Employee Resource Groups (ERGs) shortly before the COVID-19 pandemic and jumped at the chance to get more involved once employees came back onsite. “A few people have been surprised when I tell them I’m really an introvert, not an extrovert, but I had to get out of my shell or I’d still be stuck in my apartment,” she said. “The ERGs were a way for me get out of my space and have allowed me to grow.”
Kennedy is thankful the Johnson Parenting ERG started allowing contractors to serve as secretaries because that led to similar opportunities with other ERGs. She served as the membership secretary for both Emerge and Out & Allied ERG (OAERG) in 2023 and is currently OAERG’s executive secretary. “I help keep our chair and co-chair up to date,” she said. “I have my finger on everything that’s happening in the ERG.” Filling these roles gives Kennedy numerous opportunities to support diversity, equity, and inclusion at Johnson, the most recent of which was her participation on a panel during the center’s Diversity, Equity, Inclusion, and Accessibility Day.
Margaret Kennedy (left) participates in a panel discussion during Johnson Space Center’s 2024 Diversity, Equity, Inclusion, and Accessibility Day with Kent Kalogera, Out & Allied ERG chair, Livette Santiago Cardona, Greening and Restoring Our World ERG chair, Andrea Browne, African American ERG chair, and Anika Isaac, Employee Assistance Program counselor.NASA/Robert Markowitz “The main advice I’d give to others wanting to get involved is find your people and don’t be afraid to take a risk,” she said. “Many of us deal with risk every day in our work so find a way to buy down risk by finding allies and a support system. Even if you only get a hair’s width outside your zone of comfort, it makes a difference.”
She also said that simply participating in ERG meetings and events – whether in person or virtually – is another great way to get involved. “The ERGs can’t do what we do without you,” she said. “We do it because it’s important to us and to others, but we sometimes struggle to know what people want. We need your thoughts and your ideas because it helps us provide programming and inform the center about what is happening.”
Being a part of OAERG in particular has helped Kennedy personally and professionally. “It has provided me with a space to be my authentic self and bring that person to both the world and work,” she said. “In the long line of LGBTQI+ letter soup, I end up in the + on the end more times than not. Out & Allied has given me a way to not only embrace my identity but also help spread awareness about it.” Professionally, the ERG has helped her network with a range of people, including upper and middle management, and strengthen her communication, problem solving, and leadership skills.
Margaret Kennedy (center) volunteering at a Hatch Youth event in Houston, Texas, with Kent Kalogera, Out & Allied ERG chair, and Chasity Williams, the group’s former chair. Image courtesy of Margaret Kennedy Kennedy acknowledged that change can take time, noting that while Johnson’s safety-oriented culture is a strength, it can sometimes slow the pace of initiatives that may not be considered mission critical, as can staffing shortages in some areas. “Things like accessible walkways and gender-neutral bathrooms are still important,” she said, adding that leadership is working on it.
Kennedy encourages everyone at Johnson to check in with their teammates and have “water cooler moments” with their colleagues as a way of promoting inclusivity. “Be patient and willing to give everyone some grace,” she said. “We can get so focused on the mission and what we need that we sometimes forget there are things happening in other people’s lives that can affect their work.”
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