Latest news with #HeidiHammel
Yahoo
27-03-2025
- Science
- Yahoo
James Webb Space Telescope captures 1st images of Neptune's elusive auroras
When you buy through links on our articles, Future and its syndication partners may earn a commission. For the first time, astronomers have captured direct images of Neptune's elusive auroras. Scientists have long suspected that the distant ice giant hosts shimmering light displays, based on fleeting hints from the Voyager 2 probe's flyby and observations of similar activity on Jupiter, Saturn and Uranus. Capturing images of Neptune's auroras had remained out of reach until the James Webb Space Telescope (JWST or Webb) turned its powerful eye towards the icy planet. "Turns out, actually imaging the auroral activity on Neptune was only possible with Webb's near-infrared sensitivity," said Henrik Melin of Northumbria University, who conducted the research while at the University of Leicester, in a statement accompanying the photos. "It was so stunning to not just see the auroras, but the detail and clarity of the signature really shocked me." Even more significant is the unique nature of Neptune's aurora, which scientists say differs from those seen on Earth, Jupiter, and Saturn, where auroras are typically confined to the poles. This is because their magnetic fields are relatively well aligned with their rotation axes, guiding charged particles from the solar wind toward the polar regions. Neptune, on the other hand, has a highly tilted and offset magnetic field, which means its auroras appear at unexpected locations, such as the planet's mid latitudes. These observations were made possible by the James Webb Space Telescope's Near-Infrared Spectrograph (NIRSpec), an instrument that analyzes the light absorbed or emitted by celestial objects. By breaking down the different wavelenghts of this light, scientists can determine key physical properties, such as temperature, mass and chemical composition. In this case, NIRSpec captured detailed images of Neptune's ionosphere — the electrically charged layer of its upper atmosphere, similar to Earth's ionosphere, where auroras form. Excitingly, Webb's data revealed emissions of trihydrogen cation (H₃⁺), one of the most abundant ions in the universe. This discovery is significant because H₃⁺ plays a crucial role in planetary auroras, glowing in response to interactions between planets' atmospheres and charged particles from the solar wind. "H3+ has a been a clear signifier on all the gas giants — Jupiter, Saturn, and Uranus — of auroral activity, and we expected to see the same on Neptune as we investigated the planet over the years with the best ground-based facilities available," explained JWST scientist Heidi Hammel. "Only with a machine-like Webb have we finally gotten that confirmation." The team was also able to take a temperature reading of Neptune, something that hasn't been done since Voyager 2's flyby in August, 1989. "I was astonished [by the results]," Melin said. "Neptune's upper atmosphere has cooled by several hundreds of degrees [in that time]. In fact, the temperature in 2023 was just over half of that in 1989." RELATED STORIES: — Stunning light shows on Uranus and Saturn may soon draw James Webb Space Telescope's eye — Do extraterrestrial auroras occur on other planets? — Stunning light shows on Uranus and Saturn may soon draw James Webb Space Telescope's eye The dip in planetary temperature may help explain why the aurora have been so difficult to view. This is because auroras occur when charged particles excite atmospheric gases, causing them to emit light. Higher temperatures generally mean more energetic particles and a higher rate of collisions, leading to brighter auroras. A substantially colder temperature would reduce the density of energetic ions, leading to weaker emissions that are harder to detect. Astronomers will continue to study Neptune using the JWST, hoping to gain a deeper understanding of our solar system's strangest planet. "As we look ahead and dream of future missions to Uranus and Neptune, we now know how important it will be to have instruments tuned to the wavelengths of infrared light to continue to study the auroras," added Leigh Fletcher of Leicester University, co-author on the paper. "This observatory has finally opened the window onto this last, previously hidden ionosphere of the giant planets."
USA Today
13-02-2025
- Science
- USA Today
Will an asteroid collide with Earth? How the Webb telescope will track 2024 YR4
The race to understand more about the asteroid that − as of now − has a 1.8% chance of colliding with the Earth in December 2032 is getting a boost from a heavy hitter in celestial observation: the James Webb Space Telescope. In a blog post Monday confirming that the telescope would observe the near-Earth asteroid − known as 2024 YR4 − the European Space Agency (ESA) said the telescope will help astronomers more precisely determine the asteroid's size and temperature as the asteroid's orbit takes it farther from the sun. The asteroid is moving away from Earth now on its orbital path, so a larger telescope like Webb can help narrow down the asteroid's true trajectory. The Webb telescope, launched in 2021 as an international partnership of NASA, the ESA and the Canadian Space Agency, brings with it several advantages over the Earth-based telescopes tracking the asteroid: its ability to perceive light from a large swatch of the infrared range of the electromagnetic spectrum and its vantage point 1 million miles from Earth. What are the chances of of 2024 YR4 colliding with Earth? Very small − for now. More recent observational data last week put the chances of a collision with Earth at 1.8%, up slightly from the 1.2% estimate published Jan. 29. But researchers expect that additional data and observations will help astronomers refine the asteroid's trajectory. At present, the line of 500 possible asteroid positions (pictured below) on Dec. 22, 2032, measures 1.2 million miles long. The risk assessment of 1.8% is just the ratio of the Earth's diameter to that line. According to an ESA blog from Feb. 6, by the end of this month the object will be "too faint for even professional, 4 m-class telescopes to see," which makes the use of the Web telescope in refining calculations even more crucial. How large is 2024 YR4? An analysis by NASA's JPL/CNEOS has estimated the asteroid to be anywhere from 130 to 300 feet wide, a figure that hasn't changed much since the object's discovery on Dec. 27. It was first spotted at the Asteroid Terrestrial-Impact Last Alert System (ATLAS) telescope in Rio Hurtado, Chile. At that size, the ESA published in a Jan. 29 statement, an impact on Earth "could cause severe damage to a local region." "It is very important that we improve our size estimate for 2024 YR4: the hazard represented by a 40 m asteroid is very different from that of a 90 m asteroid," the ESA wrote in a blog post Feb. 10. Asteroid 2024 YR4 also rates 3 of 10 on the Torino Impact Hazard Scale, a method for astronomers to categorize and rate the threat of near-Earth objects Where is the asteroid now? 2024 YR4 follows an elliptical orbit around the sun. Though current projections don't pose an immediate impact threat to Earth, its orbit does bring it close to Earth's orbit on occasion. 'It is rare to have an asteroid with a non-zero probability of hitting Earth,' Heidi Hammel, vice president of the Planetary Society's board of directors, said in a news release. 'At this point, astronomers have measured the object's orbit, and further observations will refine that orbit to give us a more precise understanding of its potential danger." How will the James Webb Space Telescope help track 2024 YR4? The Webb Telescope launched Christmas Day in 2021 and made a splash seven months later when the first images were released in July 2022. The $10 billion observatory was designed to perceive a broader range of light from the infrared spectrum and has four main instruments in its Integrated Science Instrument Module, or ISIM. Two of these instruments, the Near-Infrared Camera (NIRCam) and Mid-Infrared Instrument (MIRI), will help astronomers track 2024 YR4's position and size, and better inform NASA and ESA of any hazards of its orbital path. The Webb Telescope, whose observational time is in high demand from institutions worldwide, has observational time set aside for teams with time-critical discoveries, like 2024 YR4. Contributing: Eric Lagatta SOURCES: NASA Jet Propulsion Laboratory, Center for Near Earth Object Studies (CNEOS); European Space Agency; Reuters
USA Today
31-01-2025
- Science
- USA Today
Astronomers find asteroid with 1% chance of hitting Earth: Should we be worried?
An asteroid recently spotted in the cosmos with a non-zero chance of hitting Earth in the coming years may have caused some alarm. Don't freak out – yet. Yes, the asteroid has little more than a 1% probability of slamming into Earth in 2032. And yes, that makes it the only one of more-than 37,000 known large space rocks near Earth with such odds. But astronomers who are keeping a close eye on the asteroid, dubbed 2024 YR4, expect that the probability will more than likely fall to zero as more observations and data about its flight path come in. 'It is rare to have an asteroid with a non-zero probability of hitting Earth,' Heidi Hammel, vice president of the Planetary Society's board of directors, said in a press release about the asteroid. 'At this point, astronomers have measured the object's orbit, and further observations will refine that orbit to give us a more precise understanding of its potential danger." Here's what to know about the asteroid 2024 YR4 and it's chances of hitting Earth: Asteroids:Apophis has the tiniest chance of hitting earth in 2029 – on a Friday the 13th How did astronomers detect the asteroid? Asteroid 2024 YR4 was spotted late last year by the NASA-funded Asteroid Terrestrial-impact Last Alert System, or ATLAS. The system includes four telescopes around the world that hunt near-Earth objects, and its telescope in Chile was the one to make the find. The object was then first reported on Dec. 27, 2024 to the Minor Planet Center, the official authority for observing and reporting new asteroids, comets and other small bodies in the solar system, according to NASA. It wasn't until a few days later that the object caught the attention of NASA and other astronomers when it rose on the U.S. Space Agency's Sentry Impact Risk Table. A program under the Center for Near-Earth Object Studies at NASA's Jet Propulsion Laboratory in California, Sentry tracks any known asteroids that have a non-zero probability of hitting Earth. The asteroid is also on the European Space Agency's NEO impact Risk List. When could 2024 YR4 hit Earth, and should we be concerned? Based on projections, the asteroid has little more than a 1% chance of impacting Earth on Dec. 22, 2032. For context, 2024 YR4 rates at a 3 on the TorinoImpact Hazard Scale. The scale, which ranges from 0 (no chance of impact) to 10 (a collision is certain and would cause worldwide devastation,) is a method for astronomers to categorize and rate the threat of near-Earth objects. Ratings of 1 on the Torino scale are fairly common among newly discovered asteroids, but follow-up observations have always reduced that rating to 0, according to the Planetary Society. Asteroid 2024 YR4's rating of 3 may be the second-highest an asteroid has ever reached after the notorious Apophis briefly hit a rating of 4 many years ago, but future data is expected to drop its impact probability down. In short, while the asteroid merits attention from astronomers and public officials, it shouldn't keep you up at night. USA TODAY exclusive:Starliner astronauts 'focus on the now' amid extended ISS stay How big is 2024 YR4? The asteroid is estimated to be about 130 to 300 feet wide. Data suggests that the asteroid has an elongated shape, while measurements at visible wavelengths suggest it may be stony in composition, according to the Planetary Society. What damage would happen if the asteroid impacted Earth? If it did collide with Earth, an asteroid of that size could cause an explosion in the atmosphere or even create an impact crater, according to the Planetary Society. Both possibilities would likely cause devastating damage on the ground, though not enough for it to be a mass extinction event. How would NASA, space agencies protect Earth from inbound space rocks? Within the last few years, NASA and the world's space agencies have taken steps to build a defense to protect humanity from threats posed by asteroids and other inbound space rocks, such as comets. In September 2022, NASA demonstrated that it was possible to nudge an incoming asteroid out of harm's way by slamming a spacecraft into it as part of its Double Asteroid Redirection Test. Launched in November 2021, DART traveled for more than 10 months before crashing into Dimorphos, which posed no threat to Earth. A craft from the European Space Agency is now on the way to get an up-close look at the asteroid's remnants. In the coming years, both NASA and the ESA have designs on sending uncrewed spacecraft to observe an infamous asteroid named Apophis, which caused some concern two decades ago when it was discovered hurtling too close for comfort toward Earth. The asteroid is projected in 2029 to pass harmlessly by Earth. The U.S. space agency's Planetary Defense Coordination Office, established in 2016, also catalogs near-Earth objects that could crash into the planet. NASA is additionally working on an asteroid-hunting telescope known as the NEO Surveyor to find near-Earth objects capable of causing significant damage. Set to launch no earlier than June 2028, the telescope is designed to discover 90% of asteroids and comets that are 460 feet in size or larger and come within 30 million miles of Earth's orbit. Eric Lagatta covers breaking and trending news for USA TODAY. Reach him at elagatta@
