Feed aggregator
Which States Have the Most Climate-Friendly Transportation
A report from the Natural Resources Defense Council looked at how states balanced transportation needs with climate and equity efforts
NASA Begins Mass Firings ahead of Trump Team’s Deadline
Top advisers in NASA’s Office of the Chief Scientist are among the first to go amid a government-wide downsizing effort
The biggest coincidence in human evolution
The biggest coincidence in human evolution
Watch sparks fly as Blue Ghost lander drills into the moon (video)
NASA Astronaut Jonny Kim to Discuss Upcoming Launch, Mission
NASA will provide interview opportunities with astronaut Jonny Kim beginning at 9 a.m. EDT, Tuesday, March 18, to highlight his upcoming mission to the International Space Station in April.
The virtual interviews from Star City, Russia, will stream live on NASA+. Learn how to watch NASA content through a variety of platforms, including social media.
Media interested in participating must contact the newsroom at NASA’s Johnson Space Center in Houston no later than 5 p.m., Monday, March 17, at 281-483-5111 or jsccommu@mail.nasa.gov. A copy of NASA’s media accreditation policy is online.
Kim will launch on Tuesday, April 8, aboard the Roscosmos Soyuz MS-27 spacecraft, accompanied by Roscosmos cosmonauts Sergey Ryzhikov and Alexey Zubritsky. The trio will spend approximately eight months aboard the orbital laboratory before returning to Earth in the fall 2025. During his time in orbit, Kim will conduct scientific investigations and technology demonstrations to help prepare the crew for future space missions and provide benefits to people on Earth.
Kim is making his first spaceflight after selection as part of the 2017 NASA astronaut class. A native of Los Angeles, he is a U.S. Navy lieutenant commander and dual designated naval aviator and flight surgeon. Kim also served as an enlisted Navy SEAL. He holds a bachelor’s degree in Mathematics from the University of San Diego and a medical degree from Harvard Medical School in Boston. He completed his internship with the Harvard Affiliated Emergency Medicine Residency at Massachusetts General Hospital and Brigham and Women’s Hospital. After completing initial astronaut candidate training, Kim supported mission and crew operations in various roles, including the Expedition 65 lead operations officer, T-38 operations liaison, and space station capcom chief engineer. Follow @jonnykimusa on X and @jonnykimusa on Instagram.
For more than two decades, people have lived and worked continuously aboard the International Space Station, advancing scientific knowledge, and making research breakthroughs that are not possible on Earth. The station is a critical testbed for NASA to understand and overcome the challenges of long-duration spaceflight and to expand commercial opportunities in low Earth orbit. As commercial companies focus on providing human space transportation services and destinations as part of a robust low Earth orbit economy, NASA is able to focus more of its resources on deep space missions to the Moon and Mars.
Learn more about International Space Station research and operations at:
-end-
Joshua Finch / Claire O’Shea
Headquarters, Washington
202-358-1100
joshua.a.finch@nasa.gov / claire.a.o’shea@nasa.gov
Raegan Scharfetter
Johnson Space Center, Houston
281-910-4989
raegan.r.scharfetter@nasa.gov
The best sci-fi TV shows of the 1960s
How to Help Butterflies That Are Disappearing
A new report finds that butterfly populations in the continental U.S. declined by one fifth between 2000 and 2020—but it’s not too late
The epic scientific quest to reveal what makes folktales so compelling
The epic scientific quest to reveal what makes folktales so compelling
Strong Scientific Leaders Must Speak Out against the Trump Administration’s Science Denial
The U.S. National Academy of Sciences should denounce the antiscientific policies of the Trump administration
Discovery Alert: ‘Super-Earth’ Swings from Super-Heated to Super-Chill
The Discovery
A possible “super-Earth” orbits a relatively close, Sun-like star, and could be a habitable world – but one of extreme temperature swings, from scorching heat to deep freeze.
Key Facts
The newly confirmed planet is the outermost of three detected so far around a star called HD 20794, just 20 light-years from Earth. Its 647-day orbit is comparable to Mars in our solar system. But this planet’s orbit is highly eccentric, stretched into an oval shape. That brings the planet close enough to the star to experience runaway heating for part of its year, then carries it far enough away to freeze any potential water on its surface. The planet has been bouncing between these extremes roughly every 300 days – perhaps for billions of years.
Details
The planet spends a good chunk of its year in the “habitable zone” around its star, the orbital distance that would allow liquid water to form on the surface under the right atmospheric conditions. But because of its eccentric orbit, it moves to a distance interior to the inner edge of the habitable zone when closest to the star, and outside the outer edge when farthest away. At its closest, the planet’s distance from the star is comparable to Venus’s distance from the Sun; at its farthest point, it is nearly twice the distance from Earth to the Sun. The planet is possibly rocky, like Earth, but could be a heftier version – about six times as massive as our home planet.
Star HD 20794 and its posse of possible planets have been extensively studied, but the international team of astronomers that confirmed the outer planet, led by Nicola Nari of Light Bridges S.L. and the Instituto de Astrofisica de Canarias, examined more than 20 years worth of data to pin down all three planets’ orbits and likely masses.
The scientists relied on data from two ground-based, precision instruments: HARPS, the High Accuracy Radial velocity Planet Searcher in La Silla, Chile, and ESPRESSO, the Echelle Spectrograph for Rocky Exoplanets and Stable Spectroscopic Observations in Paranal, Chile. Both instruments, connected to powerful telescopes, measure tiny shifts in the light spectrum of stars, caused by the gravity of planets tugging the star back and forth as they orbit.
But such tiny shifts in the star’s spectrum also can be caused by imposters – spots, flares, or other activity on the star’s surface, carried along as the star rotates and masquerading as orbiting planets. The science team spent years painstakingly analyzing the spectrum shifts, or “radial velocity” data, for any sign of background noise or even jitters from the instruments themselves. They confirmed the reputation of HD 20794 as a fairly quiet star, not prone to outbursts that might be confused for signs of orbiting planets.
Fun Facts
The elliptically orbiting super-Earth appears to be an ideal target for future space-based telescopes designed to search for habitable worlds, seeking possible signs of life. High on the list is NASA’s Habitable Worlds Observatory, which will someday examine the atmospheres of Earth-sized planets around Sun-like stars. When launched in the decades ahead, the observatory would spread the light from such planets into a spectrum to determine which gases are present – including those that might reveal some form of life. The relative closeness of HD 20974, only 20 light-years away, its brightness, and its low level of surface activity – not to mention the third planet’s wild temperature swings – could make this system a prime candidate for scrutiny by HWO.
The Discoverers
The international science team that confirmed the eccentric super-Earth was led by researcher Nicola Nari of the Light Bridges S.L. and the Instituto de Astrofisica de Canarias, and included Dr. Michael Cretignier of the University of Oxford, who first picked up the potential planet’s signal in 2022. Their paper, “Revisiting the multi-planet system of the nearby star HD 20794,” was published online by the journal, Astronomy and Astrophysics, in January 2025.
How Do We Know the Earth Isn’t Flat? We Asked a NASA Expert: Episode 53
2 min read
Preparations for Next Moonwalk Simulations Underway (and Underwater)This was a magical revelation for the Greeks and the Egyptians, who were able to see from the motions of the stars and the way the Sun moved. They saw the way the Sun’s shadow worked in different places. And they figured, well, that’s only possible if the Earth is round. And they took that information and it extended into the time of the great mariners that explored our Earth by ships.
They made the first orbit of Earth by sea, and they knew the Earth was round, allowing them to go across one ocean and come back home the other way. If the Earth were flat, they would have sailed off the end. And so we knew that.
But then, at the dawn of the space age, in the late 50s and 60s, we were able to see for ourselves that our beautiful home is a gorgeous round object known as a sphere. And that was really special. It put ourselves into context of our solar system and our universe.
We have a big round Sun and a beautiful round Earth and a round Mars.
And today we use the roundness of Earth, the spherical Earth, to use methods in space geodesy to figure out where we are, where we’re going. I haven’t been lost in years. That’s pretty good.
What’s happening to the Earth, what’s happening to our oceans as we take the pulse of our planet and consider other worlds beyond as we explore those.
So as we get ready to go back to the Moon with women and men and explore other worlds, the roundness of our solar system and our universe is a special thing. And we should embrace that as we understand why our planet isn’t flat.
[END VIDEO TRANSCRIPT]
Share Details Last Updated Mar 11, 2025 Related Terms Explore More 2 min read Hubble Unveils a Glittering View of Sh2-284A tiny fraction of the stellar nursery known as Sh2-284 is visible in this glittering,…
Article 3 days ago 3 min read Hubble Jams With A Cosmic GuitarArp 105 is a dazzling ongoing merger between an elliptical galaxy and a spiral galaxy…
Article 3 days ago 2 min read Hubble Spies a Spectacular Starburst GalaxySweeping spiral arms extend from NGC 4536, littered with bright blue clusters of star formation…
Article 3 days ago Keep Exploring Discover Related TopicsMissions
Humans in Space
Climate Change
Solar System
Can we rely on forests to soak up the extra CO2 in the atmosphere?
Can we rely on forests to soak up the extra CO2 in the atmosphere?
The next ice age is coming in 10,000 years — unless climate change prevents it
NASA’s Chevron Technology Quiets the Skies
Shortly after dawn on March 27, 2001, NASA pilot Bill Rieke took off from an airfield just outside of Phoenix in NASA’s blue-and-white Learjet 25 and flew low over a series of microphones for the first flight test of a groundbreaking NASA technology.
On one of the plane’s engines was an experimental jagged-edged nozzle that researchers at Glenn Research Center in Cleveland had discovered made aircraft significantly quieter. These initial flight tests were an important step toward using these “chevron nozzles” on modern aircraft, lowering noise levels for communities.
NASA Glenn has been exploring ways of reducing engine noise since the first jet airliners appeared in the 1950s. New turbofan engines in the 1960s were quieter, but the expansion of the overall airline industry meant that noise was still an issue. With the introduction of noise-limiting mandates in the 1970s, NASA and engine manufacturers embarked on a decades-long search for technologies to lower noise levels.
NASA researchers discovered that the military’s use of rectangular notches, or tabs, along an engine nozzle’s exit – to help disguise a jet fighter’s infrared signature – could also reduce engine noise by helping mix the hot air from the engine core and the cooler air blowing through the engine fan. In the 1990s, Glenn researcher Dennis Huff and his colleagues discovered that a serrated, or sawtooth, shape, referred to as a chevron, offered more promise.
Dennis Huff explains chevron nozzles, seen on a table, to U.S. Senator George Voinovich and other visitors inside the Aero-Acoustic Propulsion Laboratory facility in 2006. Huff was head of NASA Glenn Research Center’s Acoustics Branch at this point.Credit: NASA/Marvin Smith
NASA contracted with General Electric and Pratt & Whitney to develop an array of tab and chevron designs to be analyzed in Glenn’s unique Aero-Acoustic Propulsion Laboratory (AAPL). Extensive testing in the spring of 1997 showed the possibilities for reducing noise with these types of nozzles.
Engine manufacturers were impressed with the findings but wary of any technology that might impact performance. So, in 1998, NASA funded engine tests of the 14 most promising designs. The tests revealed the chevron nozzle had a negligible 0.25% reduction of thrust. It was a major development for jet noise research.
In September 2000, Glenn’s Flight Operations Branch was contacted about the logistics of flight-testing chevron nozzles on the center’s Learjet 25 to verify the ground tests and improve computer modeling. Nothing further came of the request, however, until early the next year when Huff informed Rieke, chief of Flight Operations, that the researchers would like to conduct flight tests in late March—with just eight weeks to prepare.
Glenn’s Acoustics Branch worked with colleagues at NASA’s Langley Research Center in Hampton, Virginia, and the Arizona-based engine manufacturer Honeywell on the effort. They planned to conduct testing at Estrella Sailport just outside of Phoenix from March 26 to 28, 2001.
Bill Rieke and Ellen Tom with the chevron nozzle installed on the Learjet. NASA Glenn Research Center’s small Flight Operations team was heavily involved with icing research and solar cell calibration flights during this period, so arrangements were made for Tom, a Federal Aviation Administration pilot, to assist with the chevron flights. Credit: Courtesy of Bill Rieke
With the required safety and design reviews, the eight-week target date would be difficult to meet for any test flight, but this one was particularly challenging as it involved modifications to the engine nacelle. While the special nozzle engineers created for the flights would allow them to switch between a six- and a 12-chevron design during testing, it also got hot quickly. This necessitated the installation of new sensors, rewiring of fire alarm cables, and the presence of an onboard test engineer to monitor the temperatures. The short turnaround also required expedited efforts to obtain flight plan approvals, verify the plane’s airworthiness, and perform normal maintenance activities.
Despite the challenges, Rieke and a small team delivered the Learjet to Estrella on March 25, as planned. The next day was spent coordinating with the large Langley and Honeywell team and acquiring baseline noise data. The pilots idled the unmodified engine as the Learjet flew over three perpendicular rows of microphones at an altitude of 500 feet and speed of 230 miles per hour.
View from below as NASA Glenn Research Center’s Learjet 25 passes overhead at the Estrella airfield with the experimental chevron nozzle visible on the left wing.Credit: Courtesy of Bill Rieke
The flight patterns were repeated over the next two days while alternately using the two variations of the chevron nozzle. The researchers anecdotally reported that there was no perceptible noise reduction as the aircraft approached, but significant reductions once it passed. Recordings supported these observations and showed that sideline noise was reduced, as well.
The flights of the Learjet, which was powered by a variation of GE’s J-85 turbojet, were complemented by Honeywell’s turbofan-powered Falcon 20 aircraft. These flights ultimately confirmed the noise reduction found in earlier AAPL tests.
Overall, the flight tests were so successful that just over a year later the FAA began certifying GE’s CF34–8, the first commercial aircraft engine to incorporate chevron technology. The engine was first flown on a Bombardier CRJ900 in 2003. Continued studies by both NASA and industry led to the improved designs and the incorporation of chevrons into larger engines, such as GE’s GEnx.
According to Huff, the chevron’s three-decibel noise decrease was analogous to the difference between running two lawnmowers and one. Their comparatively easy integration into engine design and minimal effect on thrust made the chevron a breakthrough in noise-reduction technology. In 2002, NASA presented an innovation award to the Glenn, Langley, and Honeywell team that carried out the flights. Today, airliners such as the 737 MAX and 787 Dreamliner use chevron nozzles to lower noise levels for communities near airports.
Explore More 3 min read NASA Selects Three University Teams to Participate in Flight Research Article 11 hours ago 5 min read About Pathfinding for Airspace with Autonomous Vehicles Article 22 hours ago 3 min read 40 Years Ago: Space Shuttle Atlantis Makes its Public Debut Article 24 hours agoThis Precocious Galaxy is Surprisingly Mature for its Age
Looking back in time can seem like a sci-fi fantasy. But the nature of the Universe allows us to do it if we have the right telescope. The JWST is the right telescope, and as part of its observations, it frequently examines ancient galaxies whose light is only reaching us now. One of those ancient galaxies is both bright and enriched with metals, both signs of maturity.
How COVID Shaped Education and Mental Health Outcomes for Kids
COVID’s emotional and educational strain on children still lingers, but educators and mental health specialists say they are far from a “lost generation”