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November’s Night Sky Notes: Spy the Seventh Planet, Uranus
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By NASA
Artist’s concept of a young, newly discovered planet, exposed to observation by a warped debris disk. Credit: Robert Hurt, Caltech-IPAC. The discovery
A huge planet with a long name – IRAS 04125+2902 b – is really just a baby: only 3 million years old. And because such infant worlds are usually hidden inside obscuring disks of debris, it is the youngest planet so far discovered using the dominant method of planet detection.
Key facts
The massive planet, likely still glowing from the heat of its formation, lies in the Taurus Molecular Cloud, an active stellar nursery with hundreds of newborn stars some 430 light-years away. The cloud’s relative closeness makes it a prime target for astronomers. But while the cloud offers deep insight into the formation and evolution of young stars, their planets are usually a closed book to telescopes like TESS, the Transiting Exoplanet Survey Satellite. These telescopes rely on the “transit method,” watching for the slight dip in starlight when a planet crosses the face of its host star. But such planetary systems must be edge-on, from Earth’s vantage point, for the transit method to work. Very young star systems are surrounded by disks of debris, however, blocking our view of any potentially transiting planets.
A research team has just reported an extraordinary stroke of luck. Somehow, the outer debris disk surrounding this newborn planet, IRAS 04125+2902 b, has been sharply warped, exposing the baby world to extensive transit observations by TESS.
Details
While the warped outer disk is a great coincidence, it’s also a great mystery. Possible explanations include a migration of the planet itself, moving closer to the star and, in the process, diverging from the orientation of the outer disk – so that, from Earth, the planet’s orbit is edge-on, crossing the face of the star, but the outer disk remains nearly face-on to us. One problem with this idea: Moving a planet so far out of alignment with its parent disk would likely require another (very large) object in this system. None has been detected so far.
The system’s sun happens to have a distant stellar companion, also a possible culprit in the warping of the outer disk. The angle of the orbit of the companion star, however, matches that of the planet and its parent star. Stars and planets tend to take the gravitational path of least resistance, so such an arrangement should push the disk into a closer alignment with the rest of the system – not into a radical departure.
Another way to get a “broken” outer disk, the study authors say, would not involve a companion star at all. Stellar nurseries like the Taurus Molecular Cloud can be densely packed, busy places. Computer simulations show that rains of infalling material from the surrounding star-forming region could be the cause of disk-warping. Neither simulations nor observations have so far settled the question of whether warped or broken disks are common or rare in such regions.
Fun facts
Combining TESS’s transit measurements with another way of observing planets yields more information about the planet itself. We might call this second approach the “wobble” method. The gravity of a planet tugs its star one way, then another, as the orbiting planet makes its way around the star. And that wobble can be detected by changes in the light from the star, picked up by specialized instruments on Earth. Such “radial velocity” measurements of this planet reveal that its mass, or heft, amounts to no more than about a third of our own Jupiter. But the transit data shows the planet’s diameter is about the same. That means the planet has a comparatively low density and, likely, an inflated atmosphere. So this world probably is not a gas giant like Jupiter. Instead, it could well be a planet whose atmosphere will shrink over time. When it finally settles down, it could become a gaseous “mini-Neptune” or even a rocky “super-Earth.” These are the two most common planet types in our galaxy – despite the fact that neither type can be found in our solar system.
The discoverers
A science team led by astronomer Madyson G. Barber of the University of North Carolina at Chapel Hill published the study, “A giant planet transiting a 3 Myr protostar with a misaligned disk,” in the journal Nature in November 2024.
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By NASA
4 min read
Preparations for Next Moonwalk Simulations Underway (and Underwater)
NASA’s Voyager 2 captured this image of Uranus while flying by the ice giant in 1986. New research using data from the mission shows a solar wind event took place during the flyby, leading to a mystery about the planet’s magnetosphere that now may be solved.NASA/JPL-Caltech NASA’s Voyager 2 flyby of Uranus decades ago shaped scientists’ understanding of the planet but also introduced unexplained oddities. A recent data dive has offered answers.
When NASA’s Voyager 2 spacecraft flew by Uranus in 1986, it provided scientists’ first — and, so far, only — close glimpse of this strange, sideways-rotating outer planet. Alongside the discovery of new moons and rings, baffling new mysteries confronted scientists. The energized particles around the planet defied their understanding of how magnetic fields work to trap particle radiation, and Uranus earned a reputation as an outlier in our solar system.
Now, new research analyzing the data collected during that flyby 38 years ago has found that the source of that particular mystery is a cosmic coincidence: It turns out that in the days just before Voyager 2’s flyby, the planet had been affected by an unusual kind of space weather that squashed the planet’s magnetic field, dramatically compressing Uranus’ magnetosphere.
“If Voyager 2 had arrived just a few days earlier, it would have observed a completely different magnetosphere at Uranus,” said Jamie Jasinski of NASA’s Jet Propulsion Laboratory in Southern California and lead author of the new work published in Nature Astronomy. “The spacecraft saw Uranus in conditions that only occur about 4% of the time.”
The first panel of this artist’s concept depicts how Uranus’s magnetosphere — its protective bubble — was behaving before the flyby of NASA’s Voyager 2. The second panel shows an unusual kind of solar weather was happening during the 1986 flyby, giving scientists a skewed view of the magnetosphere.NASA/JPL-Caltech Magnetospheres serve as protective bubbles around planets (including Earth) with magnetic cores and magnetic fields, shielding them from jets of ionized gas — or plasma — that stream out from the Sun in the solar wind. Learning more about how magnetospheres work is important for understanding our own planet, as well as those in seldom-visited corners of our solar system and beyond.
That’s why scientists were eager to study Uranus’ magnetosphere, and what they saw in the Voyager 2 data in 1986 flummoxed them. Inside the planet’s magnetosphere were electron radiation belts with an intensity second only to Jupiter’s notoriously brutal radiation belts. But there was apparently no source of energized particles to feed those active belts; in fact, the rest of Uranus’ magnetosphere was almost devoid of plasma.
The missing plasma also puzzled scientists because they knew that the five major Uranian moons in the magnetic bubble should have produced water ions, as icy moons around other outer planets do. They concluded that the moons must be inert with no ongoing activity.
Solving the Mystery
So why was no plasma observed, and what was happening to beef up the radiation belts? The new data analysis points to the solar wind. When plasma from the Sun pounded and compressed the magnetosphere, it likely drove plasma out of the system. The solar wind event also would have briefly intensified the dynamics of the magnetosphere, which would have fed the belts by injecting electrons into them.
The findings could be good news for those five major moons of Uranus: Some of them might be geologically active after all. With an explanation for the temporarily missing plasma, researchers say it’s plausible that the moons actually may have been spewing ions into the surrounding bubble all along.
Planetary scientists are focusing on bolstering their knowledge about the mysterious Uranus system, which the National Academies’ 2023 Planetary Science and Astrobiology Decadal Survey prioritized as a target for a future NASA mission.
JPL’s Linda Spilker was among the Voyager 2 mission scientists glued to the images and other data that flowed in during the Uranus flyby in 1986. She remembers the anticipation and excitement of the event, which changed how scientists thought about the Uranian system.
“The flyby was packed with surprises, and we were searching for an explanation of its unusual behavior. The magnetosphere Voyager 2 measured was only a snapshot in time,” said Spilker, who has returned to the iconic mission to lead its science team as project scientist. “This new work explains some of the apparent contradictions, and it will change our view of Uranus once again.”
Voyager 2, now in interstellar space, is almost 13 billion miles (21 billion kilometers) from Earth.
News Media Contacts
Karen Fox / Molly Wasser
NASA Headquarters, Washington
202-358-1600
karen.c.fox@nasa.gov / molly.l.wasser@nasa.gov
Gretchen McCartney
Jet Propulsion Laboratory, Pasadena, Calif.
818-393-6215
gretchen.p.mccartney@jpl.nasa.gov
2024-156
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Last Updated Nov 11, 2024 Related Terms
Voyager 2 Heliophysics Jet Propulsion Laboratory Magnetosphere Solar Wind Uranus Uranus Moons Explore More
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By NASA
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NASA-Funded Study Examines Tidal Effects on Planet and Moon Interiors
NASA-supported scientists have developed a new method to compute how tides affect the interiors of planets and moons. Importantly, the new study looks at the effects of body tides on objects that don’t have a perfectly spherical interior structure, which is an assumption of most previous models.
The puzzling, fascinating surface of Jupiter’s icy moon Europa looms large in this newly-reprocessed color view, made from images taken by NASA’s Galileo spacecraft in the late 1990s. This is the color view of Europa from Galileo that shows the largest portion of the moon’s surface at the highest resolution. NASA/JPL-Caltech/SETI Institute Body tides refer to the deformations experienced by celestial bodies when they gravitationally interact with other objects. Think of how the powerful gravity of Jupiter tugs on its moon Europa. Because Europa’s orbit isn’t circular, the crushing squeeze of Jupiter’s gravity on the moon varies as it travels along its orbit. When Europa is at its closest to Jupiter, the planet’s gravity is felt the most. The energy of this deformation is what heats up Europa’s interior, allowing an ocean of liquid water to exist beneath the moon’s icy surface.
“The same is true for Saturn’s moon Enceladus.” says co-author Alexander Berne of CalTech in Pasadena and an affiliate at NASA’s Jet Propulsion Laboratory in Southern California. “Enceladus has an ice shell that is expected to be much more non-spherically symmetric than that of Europa.”
The body tides experienced by celestial bodies can affect how the worlds evolve over time and, in cases like Europa and Enceladus, their potential habitability for life as we know it. The new study provides a means to more accurately estimate how tidal forces affect planetary interiors.
In this movie Europa is seen in a cutaway view through two cycles of its 3.5 day orbit about the giant planet Jupiter. Like Earth, Europa is thought to have an iron core, a rocky mantle and a surface ocean of salty water. Unlike on Earth, however, this ocean is deep enough to cover the whole moon, and being far from the sun, the ocean surface is globally frozen over. Europa’s orbit is eccentric, which means as it travels around Jupiter, large tides, raised by Jupiter, rise and fall. Jupiter’s position relative to Europa is also seen to librate, or wobble, with the same period. This tidal kneading causes frictional heating within Europa, much in the same way a paper clip bent back and forth can get hot to the touch, as illustrated by the red glow in the interior of Europa’s rocky mantle and in the lower, warmer part of its ice shell. This tidal heating is what keeps Europa’s ocean liquid and could prove critical to the survival of simple organisms within the ocean, if they exist. The giant planet Jupiter is now shown to be rotating from west to east, though more slowly than its actual rate. NASA/JPL-Caltech The paper also discusses how the results of the study could help scientists interpret observations made by missions to a variety of different worlds, ranging from Mercury to the Moon to the outer planets of our solar system.
The study, “A Spectral Method to Compute the Tides of Laterally Heterogeneous Bodies,” was published in The Planetary Science Journal.
For more information on NASA’s Astrobiology Program, visit:
https://science.nasa.gov/astrobiology
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Karen Fox / Molly Wasser
Headquarters, Washington
202-358-1600
karen.c.fox@nasa.gov / molly.l.wasser@nasa.gov
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While observing the Orion Nebula with his 12-inch Dobsonian telescope, a sky-watcher noticed an unusual flashing object. As stars appeared to drift due to Earth's rotation, this particular object while flashing approximately every 20 seconds clearly travels through deep space.
The observer wonders whether it might be a rotating satellite or not. However, this isn’t the first sighting of cigar-shaped UFOs or other mysterious objects traveling through space near the Orion Nebula, so it is quite possible that it could be an interstellar craft.
Over the years, I have shared several articles, complete with images and videos, documenting similar UFO sightings around the Orion Nebula. You can explore these under the tag: Orion Nebula.
Interestingly, these sightings have all occurred between November and February, suggesting there may be a seasonal pattern to these observations.
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By NASA
Curiosity Navigation Curiosity Home Mission Overview Where is Curiosity? Mission Updates Science Overview Instruments Highlights Exploration Goals News and Features Multimedia Curiosity Raw Images Images Videos Audio Mosaics More Resources Mars Missions Mars Sample Return Mars Perseverance Rover Mars Curiosity Rover MAVEN Mars Reconnaissance Orbiter Mars Odyssey More Mars Missions The Solar System The Sun Mercury Venus Earth The Moon Mars Jupiter Saturn Uranus Neptune Pluto & Dwarf Planets Asteroids, Comets & Meteors The Kuiper Belt The Oort Cloud 3 min read
Sols 4352-4354: Halloween Fright Night on Mars
NASA’s Mars rover Curiosity acquired this image of the target surface feature nicknamed “Reds Meadow,” using its Mars Hand Lens Imager (MAHLI), located on the turret at the end of the rover’s robotic arm. Curiosity captured the image Oct. 31, 2024, at 19:09:10 UTC, on sol 4350 — Martian day 4,350 of the Mars Science Laboratory Mission. NASA/JPL-Caltech/MSSS Earth planning date: Friday, Nov. 1, 2024
Yesterday evening (Thursday) was Halloween for many of us here on Earth. My neighborhood in eastern Canada was full of small (and not so small!) children, running around in the dark collecting sweets and candy but also getting scared by the ghostly decorations hung at each house. Little did we suspect that our poor rover on Mars was also getting spooked. Curiosity completed about a meter (about 3 feet) of the planned drive before becoming unsettled … scared, if you will! … when its left front wheel got hung up on a rock and stopped moving.
Luckily, we understood this kind of frightened behavior and were able to resume planning today as per usual. That meter was enough to give us a whole new set of targets to choose from. As APXS Strategic Planner this week, I had chosen darker-looking targets in the workspace — “Ladder Lake” and “Reds Meadow” (shown in the accompanying MAHLI image) — earlier in the week. I was happy that bumping backwards by a meter allowed us to reach some of the more typical pale colored bedrock at “Eureka Valley” and a second APXS analysis on “Black Bear Lake,” which is a mixture of both pale bedrock and some darker layers. MAHLI added in a bonus set of images on “Stag Dome,” focusing on small, rougher patches on the pale bedrock.
ChemCam is taking advantage of the short bump, too, adding a passive observation on the brushed Reds Meadow target, analyzed by APXS and MAHLI in Monday’s plan. A ChemCam LIBS target “Hoist Ridge” focuses on a small vertical face of dark material. Two long distance images planned for ChemCam’s Remote Micro Imager (RMI) look at the distribution of rocks along the Gediz Vallis ridge in the distance.
Mastcam is taking several mosaics this weekend (must have gotten extra energy from the Halloween sugar!). Close to the rover, Mastcam will acquire single-frame images of the targets Hoist Ridge and Eureka Valley, and a small mosaic of some surficial troughs just a little further away. Moving further afield, a small 3×1 mosaic (three images in one row) will image the same area as the ChemCam RMI of the Gediz Vallis ridge, and a larger 9×2 mosaic will focus on the faraway yardang unit, where we hopefully will be in a few years.
Then for the really big images: Mastcam will image the whole landscape in a special 360-degree view, so big it needs to be broken into two parts. The first will have 43×4 frames, the second 34×5 frames. These mosaics are huge, so we save them for when we are at a really good vantage point to allow us to capture as much detail as possible for science and engineering planning.
As ever, we continue our environmental monitoring of conditions, with Mastcam and Navcam movies and images looking at dust in the atmosphere above and around us in Gale crater, and watching out for dust devils.
Written by Catherine O’Connell-Cooper, Planetary Geologist at University of New Brunswick
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Last Updated Nov 04, 2024 Related Terms
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