Latest news with #Umbriel
Yahoo
3 days ago
- Science
- Yahoo
'Uranus is weird.' Big moons of tilted ice giant hide a magnetic mystery, Hubble telescope reveals
When you buy through links on our articles, Future and its syndication partners may earn a commission. New data from the Hubble Space Telescope suggests that Uranus' largest moons are gathering dust — literally. Uranus, the seventh planet from the sun and home to 28 known moons, is well known for its bizarre tilt. The planet spins almost completely on its side, an oddball orientation that twists its magnetic field into a warped and constantly shifting force, which scientists have long thought would leave visible scars on its moons by bombarding them with charged particles. However, new Hubble Space Telescope observations of Uranus' four largest moons — Ariel, Umbriel, Titania and Oberon — show no clear signs of the expected radiation damage, Christian Soto of the Space Telescope Science Institute in Maryland, who led the analysis, told reporters on Tuesday (June 10) at the 246th American Astronomical Society (AAS) press conference in Alaska. Based on data from NASA's Voyager 2 flyby in 1986 and decades of modeling, scientists expected the trailing hemispheres of Uranus' moons — the sides opposite their direction of travel — to be visibly darkened by radiation. The leading sides, by contrast, were expected to remain relatively brighter. Instead, the researchers found that the two outer moons, Titania and Oberon, are darker on their leading sides, the opposite of what they had predicted. The visible darkening, they say, doesn't come from Uranus' magnetic field at all, but from dust. Hubble's data points to a slow inward drift of dust from Uranus' distant irregular moons, which orbit between 2.5 to 13 million miles (4 to 20 million kilometers) from the planet. These outer moons are constantly bombarded by micrometeorites, which kick up particles that gradually spiral inward over millions of years, Soto said. As Titania and Oberon travel through this diffuse dust cloud, they accumulate the particles mostly on their leading sides. "Think of driving very fast on a highway, and bugs are hitting your windshield — that's what we're seeing here," Soto said during the press briefing. Interestingly, the inner moons Ariel and Umbriel show no significant difference in brightness between their leading and trailing sides — possibly because the drifting dust doesn't reach them, thanks to shielding by Titania and Oberon. "Dust collection — I didn't even expect to get into that hypothesis," Richard Cartwright, a planetary scientist at the Johns Hopkins University's Applied Physics Laboratory in Maryland, said in a statement. "But you know, data always surprise you." As for the role of Uranus' powerful magnetic field, researchers now suspect that its effects might be subtler or more complex than previously thought. It may still be interacting with the moons, but not in a way that creates strong contrasts on their surfaces. RELATED STORIES: — Uranus: Everything you need to know about the coldest planet in the solar system — Are there hidden oceans inside the moons of Uranus? Their wobbles could tell us — A day on Uranus is actually longer than we thought, Hubble Telescope reveals "Uranus is weird, so it's always been uncertain how much the magnetic field actually interacts with its satellites," Cartwright said in the statement. The findings highlight how little we still know about Uranus. Apart from Voyager 2's brief flyby nearly 40 years ago, coincidentally during a rare solar event, no dedicated mission has ever visited the planet. To learn more, Soto's team has scheduled follow-up observations with the James Webb Space Telescope within the next year. Using infrared imaging, Webb will take a closer look at the same moons, potentially confirming whether dust, radiation or a combination of both is shaping their surfaces. "Why do we do this?" Soto said at the briefing. "Well, Uranus is weird — so why not?"
Forbes
3 days ago
- Science
- Forbes
Hubble Space Telescope Reveals Moons And Rings Of ‘Weird' Uranus
NASA's Hubble Space Telescope has snapped new images of the solar system's seventh planet, Uranus, revealing not only its rings but new secrets about its intriguing moons and how its magnetic field works. The five largest moons of Uranus – sometimes called the 'classical moons' — appear in a jagged, ... More roughly diagonal line from top right to bottom left. These are labeled Titania, Oberon, Umbriel, Miranda and Ariel. Also visible is Ariel's shadow, which is superimposed on Uranus. Faint, ghostly, Saturn-like rings encircle the blue ice giant. Hubble's new ultraviolet image of Uranus, taken with its Advanced Camera for Surveys, shows the gas giant planet in space with its five largest moons — often referred to as its 'classical moons' — in a jagged line. The moons — Titania, Oberon, Umbriel, Miranda and Ariel — were captured in the image, which was published on June 10. Ariel can be seen transiting the disk of Uranus, with its shadow apparent on the planet's blue methane-rich atmosphere. All may be 'ocean worlds,' which could host life. The image also shows faint, ghostly rings around Uranus. According to NASA, Uranus has 13 faint rings in total, divided into two distinct sets. In 2023, the James Webb Space Telescope imaged the rings of Uranus and six of its 27 moons and is expected to do so again. The five largest moons of Uranus – sometimes called the 'classical moons' — appear in a jagged, ... More roughly diagonal line from top right to bottom left. These are labeled Titania, Oberon, Umbriel, Miranda and Ariel. Also visible is Ariel's shadow, which is superimposed on Uranus. Faint, ghostly, Saturn-like rings encircle the blue ice giant. This new study, presented during a press conference at AAS 246 in Anchorage, Alaska, on Tuesday, June 10, examines the magnetic environment of Uranus and its largest moons. It reveals surprising findings. Scientists had expected that radiation from the magnetic field of Uranus would darken the trailing hemispheres of its moons, but an analysis of the surfaces of Uranus' four major moons — Ariel, Umbriel, Titania and Oberon — found the opposite. That suggests that Uranus' magnetosphere might not interact much with its large moons, and it may be either dormant or much more complicated than previously thought. 'Uranus is weird, so it's always been uncertain how much the magnetic field actually interacts with its satellites,' said Richard Cartwright, principal investigator at the Johns Hopkins University's Applied Physics Laboratory in Laurel, Maryland. 'For starters, it is tilted by 98 degrees relative to the ecliptic." That means it rolls on its side as it completes its 84-Earth-year orbit of the sun. The two ice giant planets in the solar system — Uranus and Neptune — remain unexplored, having had only brief flybys by Voyager 2 in 1986 and 1989, respectively. Planetary scientists' lack of detailed knowledge about ice giants (large planets composed mainly of elements heavier than hydrogen and helium) has become more significant in recent years, particularly with research into exoplanets — planets that orbit a star other than the sun. According to research, the most typical size of exoplanets in the Milky Way is between that of Earth and Neptune, which are likely to be ice giants. If astronomers are to understand other star systems, they need a baseline — and that means sending a mission to Uranus or Neptune. Hopes are fading for a much-needed NASA flagship mission to Uranus. Despite being recommended as NASA's highest priority large mission in 2022 by the National Academy of Sciences, the likelihood of a $4.2 billion orbiter — with an atmospheric probe to dive beneath its clouds — is now small in the light of a 'destructive proposal' by the Trump Administration to cut almost $6 billion (24%) from the space agency's budget. Scientists want NASA to send the mission in 2032, with a planned arrival at Uranus in 2045. The next best launch window is in the 2090s.
