Latest news with #LaurentLamy
Yahoo
10-04-2025
- Science
- Yahoo
We Were Wrong About Uranus: New Study Solves Long-Standing Mysteries
New observations have revealed that we were wrong about the length of a day on Uranus. According to the most precise measurements yet of the stinky planet's rotation rate, a full day on Uranus lasts 17 hours, 14 minutes, and 52 seconds. That's 28 whole seconds longer than we thought, based on data collected by Voyager 2 on its Uranus flyby in 1986. That might not seem like a big deal… but it is actually huge. "Our measurement not only provides an essential reference for the planetary science community but also resolves a long-standing issue: previous coordinate systems based on outdated rotation periods quickly became inaccurate, making it impossible to track Uranus' magnetic poles over time," explains astrophysicist Laurent Lamy of the Paris Observatory. Uranus and Neptune are the two outermost worlds of the Solar System, at significantly greater distances from the Sun than the rest of the planets. Uranus is twice the orbital distance of Saturn; Neptune is more than three times Saturn's orbital distance. Because they are so far, Uranus and Neptune appear small and dim, which makes them difficult to study; in addition, that distance makes them a longer trek for spacecraft, so only the Voyager mission has been close, decades ago. This means the information we have about the outer Solar System's ice giants is limited, and may potentially be biased by the particular conditions affecting the planets at the time of the flybys. Getting new information, on the other hand, is a bit of a challenge. The inaccuracy in our assumption about the length of the Uranian day has resulted in some confusion. One of the biggest problems was that, without an accurate length-of-day, the orientation of Uranus's magnetic poles was lost just a few years after the Voyager 2 flyby. To remeasure the length of a Uranus day, Lamy and his colleagues made a careful study of data collected by the Hubble Space Telescope between 2011 and 2022. In that timespan, the telescope repeatedly observed the planet's ultraviolet auroras, which are generated a lot like the aurora here on Earth. Particles borne on the solar wind smack into the planetary magnetosphere, and are whisked away and accelerated along the lines of the magnetic field to the polar latitudes, where they are dumped into the upper atmosphere. Interactions between particles in the atmosphere and the incoming solar particles make a glow in the sky. One of the funny things about Uranus is that its rotational axis is almost parallel to the ecliptic, the orbital plane on which the planets all more or less move around the Sun, compared to the almost-perpendicular orientation of the rest of the planets. This orientation has made its magnetic poles a little harder to find. By tracking the ultraviolet auroras, Lamy and his colleagues were able to locate and trace the poles, and used that information to precisely measure the length of the Uranian day. This measurement is p-r-e-c-i-s-e – the most precise yet for a giant planet, the researchers say, even more precise than measurements of Jupiter's rotation rate. The technique used to measure the rate can thus be applied to the rest of the giant worlds in the Solar System to obtain precise measurements of their inner rotation rates. "With this new longitude system, we can now compare auroral observations spanning nearly 40 years and even plan for the upcoming Uranus mission," Lamy says. The research has been published in Nature Astronomy. Infrared AI Camera Proposed to Scan Earth's Skies For Signs of Alien Visitors 'City Killer' Asteroid's Origin Traced to an Unexpected Part of The Solar System ESA Report Says There's Too Much Junk in Earth Orbit Trunk
Yahoo
09-04-2025
- Science
- Yahoo
Glowing aurora lights on Uranus help scientists determine a day is 28 seconds longer on sideways planet
Space weather creates the Northern Lights on Earth, and more recently, aurora lights on Uranus helped Nasa's Hubble Space Telescope measure the planet's interior rotation rate, changing what astronomers know about how long a day is on the cold and windy world. Previous estimates of Uranus' rotation rate came from NASA's Voyager 2 spacecraft flyby in 1986. However, more recent observations using the mighty Hubble Space Telescope and a new technique have found that the estimate was just a little off by about half a minute. Uranus Isn't As Weird As Scientists Thought; It Just Took Nearly 40 Years To Find Out Why Astronomer Laurent Lamy with the Laboratory for Instrumentation and Research in Astrophysics (LIRA) in Paris developed a new technique to track the rotational motion of the aurora on Uranus using Hubble. These light displays are generated in the upper atmosphere from energetic particles near the planet's magnetic poles. According to those findings, a full rotation or "day" on Uranus is 17 hours, 14 minutes and 52 seconds long, which is 28 seconds longer than the estimate calculated from Voyager 2 data in 1986. Auroras are a known phenomenon on Earth, Jupiter and Saturn. However, unlike these other planets, the glowing lights on Uranus are unique because of their unpredictable manner, which is due to the planet's tilted magnetic field. Thankfully, Hubble has observed these aurora emissions on the sideways planet for more than a decade, allowing astronomers to track the positions of the magnetic poles. Astronomers Reveal What Uranus And Neptune Really Look Like "Our measurement not only provides an essential reference for the planetary science community but also resolves a long-standing issue: previous coordinate systems based on outdated rotation periods quickly became inaccurate, making it impossible to track Uranus' magnetic poles over time," Lamy said. "With this new longitude system, we can now compare auroral observations spanning nearly 40 years and even plan for the upcoming Uranus mission." Robotic missions could reveal more secrets of Uranus in the next decade. The planet is considered a high priority for NASA and the European Space Agency. NASA plans to explore a possible flagship mission, including an orbiter to Uranus and a probe dropped into the article source: Glowing aurora lights on Uranus help scientists determine a day is 28 seconds longer on sideways planet
Yahoo
09-04-2025
- Science
- Yahoo
A day on Uranus is 28 seconds longer than scientists thought
When you buy through links on our articles, Future and its syndication partners may earn a commission. A day on Uranus is about half a minute longer than previously thought, according to new research. An analysis of 11 years of Hubble Space Telescope observations shows that Uranus' day lasts 17 hours, 14 minutes, and 52 seconds. That's 28 seconds longer than NASA's Voyager 2 spacecraft estimated when it passed Uranus in 1986. Researchers reported the updated estimate April 7 in the journal Nature Astronomy. Nearly 40 years ago, Voyager 2 became the first spacecraft to observe Uranus up-close. Using radio signals from the planet's auroras and magnetic field data collected by the spacecraft, astronomers at the time found that Uranus' day lasted approximately 17 hours, 14 minutes and 24 seconds. Researchers used that rotation period to define a coordinate system for the planet. But the measured period came with an inherent uncertainty of about 36 seconds, which gradually added up as each Uranian day passed. Within a few years, the uncertainty made it impossible to accurately determine the orientation of the planet's magnetic axis. To get more reliable estimates of the planet's rotational period, the authors of the new study tracked the movement of auroras at Uranus' magnetic poles from six sets of Hubble observations taken between 2011 and 2022. This helped them refine the locations of the planet's magnetic poles, which they used to work out a more accurate estimate of Uranus' rotational period. The new measurement has an uncertainty of less than 0.04 seconds, according to the team. "The continuous observations from Hubble were crucial," first study author Laurent Lamy, an astronomer at the Paris Observatory, said in a statement. "Without this wealth of data, it would have been impossible to detect the periodic signal with the level of accuracy we achieved." Related: 'Hidden' rings of Uranus revealed in dazzling new James Webb telescope images The 28-second difference is within the margin of error of Voyager 2's calculation, but the new duration has a much lower uncertainty. "It's not so much that it's changed," Tim Bedding, an astronomer at the University of Sydney in Australia, told New Scientist. "It's now accurate enough to be more useful." RELATED STORIES —Uranus and Neptune aren't made of what we thought, new study hints —James Webb telescope to zoom in on Uranus and Saturn in study of mysterious auroras —James Webb telescope captures auroras on Neptune for first time ever With this smaller uncertainty, the coordinate system based on the new measurement of Uranus' rotational period should hold up for several decades, the team said. Future missions to Uranus, such as the proposed Uranus Orbiter and Probe, could rely on this coordinate system when selecting an atmospheric entry site, the researchers wrote in the study. "With this new longitude system, we can now compare auroral observations spanning nearly 40 years and even plan for the upcoming Uranus mission," Lamy said in the statement.
Yahoo
08-04-2025
- Science
- Yahoo
A day on Uranus is actually longer than we thought, Hubble Telescope reveals
When you buy through links on our articles, Future and its syndication partners may earn a commission. Uranus just got a little more time on its hands. A fresh analysis of a decade's worth of Hubble Space Telescope observations shows Uranus takes 17 hours, 14 minutes and 52 seconds to complete a full rotation — that's 28 seconds longer than the estimate provided by NASA's Voyager 2 spacecraft nearly four decades ago. In January 1986, Voyager 2 became the first — and so far the only — spacecraft to explore Uranus, and with its data, astronomers pegged the ice giant's rotation period at 17 hours, 14 minutes and 24 seconds. This estimate was based on radio signals emitted by the pale turquoise planet's auroras and direct magnetic field measurements. This figure became the bedrock for calculating coordinates on the enigmatic world and mapping its surface. Scientists may need to rethink some of those maps, a new study suggests. The initial estimate based on Voyager 2 data carried inherent uncertainties that led to a 180-degree error in Uranus' longitude, causing the orientation of its magnetic axis to become "completely lost" within just a couple of years after the spacecraft's flyby. Consequently, coordinate systems relying on the outdated rotation period quickly lost their reliability, according to the study. To resolve this issue, a team of astronomers led by Laurent Lamy of the Paris Observatory tracked the motion of Uranus's auroras using Hubble Space Telescope data collected between 2011 and 2022. By tracking the movement of these luminous displays over a little more than a decade, the researchers were able to precisely pinpoint the planet's magnetic poles and, in turn, a better estimate of its rotational period. "The continuous observations from Hubble were crucial," Lamy added in a statement. "Without this wealth of data, it would have been impossible to detect the periodic signal with the level of accuracy we achieved." This approach can now be used to determine the rotation rate of any celestial object with a magnetic field and auroras, not only in our solar system but also on exoplanets and other faraway worlds, the researchers say. Related Stories: — Changing seasons on Uranus tracked across 20 years by Hubble Space Telescope — Spiral starburst galaxy glows in gorgeous Hubble Telescope image — Hubble Telescope discovers a new '3-body problem' puzzle among Kuiper Belt asteroids (video) The updated estimate of Uranus' rotation period has provided a much more reliable coordinate system for the ice giant, one that is expected to remain accurate for decades until future missions can offer even more refined data, according to the new study. The improved estimate could also be useful in planning future missions to Uranus, particularly in defining orbital tours and selecting suitable atmospheric entry sites, Lamy and his team wrote in the new study. This research is described in a paper published Monday (April 7) in the journal Nature Astronomy.
Yahoo
07-04-2025
- Science
- Yahoo
Uranus' day is longer than expected, researchers find
(WHTM) – The Hubble Space Telescope has been measuring Uranus' interior rotation and determined that a day on the planet is longer than initially thought. According to a French-led team of researchers, a day on Uranus is 17 hours, 14 minutes, and 52 seconds. This is 28 seconds longer than the estimate obtained by NASA's Voyager 2 in 1986. Astronomers spot new tiny moons around Neptune and Uranus Scientists say reining in the exact timing of Uranus' full rotation took an 'innovative method' and used more than a decade of Hubble observations of Uranus' aurorae. The aurorae are described as 'spectacular light displays generated in the upper atmosphere by the influx of energetic particles near the planet's magnetic poles.' 'Our measurement not only provides an essential reference for the planetary science community but also resolves a long-standing issue: previous coordinate systems based on outdated rotation periods quickly became inaccurate, making it impossible to track Uranus' magnetic poles over time,' explains Laurent Lamy of LIRA, Observatoire de Paris-PSL and LAM, Aix-Marseille Univ., France. 'With this new longitude system, we can now compare auroral observations spanning nearly 40 years and even plan for the upcoming Uranus mission.' Close Thanks for signing up! Watch for us in your inbox. Subscribe Now Lamy added that continuing to observe Uranus has been 'crucial' for researchers to achieve the level of accuracy in determining the full time of rotation. Uranus is known to be a 'very cold and windy' planet, according to NASA, and on average is 1.8 million miles away from Earth. The planet, which rotates on a nearly 90-degree angle, is surrounded by 13 rings and 28 moons. Copyright 2025 Nexstar Media, Inc. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.
