All posts tagged: Planetary Science

Frozen ocean world found lurking between Mars and Jupiter

Frozen ocean world found lurking between Mars and Jupiter

Published by Jenni Sidey

The scars on Ceres should have softened by now. That was the long-running problem. If the dwarf planet’s crust held a great deal of ice, many of its craters should have slowly sagged over geologic time, their sharp bowls easing into shallower shapes. Instead, NASA’s Dawn spacecraft found a world still marked by deep impacts, landslides, pits, domes and bright patches that hinted at buried ice, while also seeming to argue against too much of it. A new study now tries to resolve that contradiction. In Nature Astronomy, researchers from Purdue University and NASA’s Jet Propulsion Laboratory argue that Ceres may be far icier than many scientists had come to accept, with an outer crust made not of mostly dry rock but of dirty ice, possibly reaching about 90% ice near the surface and becoming less icy with depth. That would make Ceres less like a dry leftover of the asteroid belt and more like the frozen remnant of an ancient muddy ocean world. Schematic of simulated crustal structures. (CREDIT: Nature Astronomy) A crust that …

Frozen ocean world discovered between Mars and Jupiter

Frozen ocean world discovered between Mars and Jupiter

Published by Jenni Sidey

Astronomers have long been intrigued by the makeup of the asteroid belt’s largest body. When it was first spotted in 1801, Ceres appeared dry and rocky, its surface marked by craters and dents. For years, that view held strong. Most believed that Ceres was less than 30% ice and too solid to have held much water. That idea may now be outdated. Fresh findings suggest Ceres could be far more icy than scientists had guessed. New research points to a frozen past, one where the dwarf planet may have once been a muddy ocean world. The updated theory casts doubt on earlier beliefs about its dry, rocky nature. A team from Purdue University and NASA’s Jet Propulsion Laboratory is behind the breakthrough. Their study, published in Nature Astronomy, proposes that up to 90% of Ceres’ outer layers could be ice. Instead of solid rock, they believe the crust is dirty ice—formed as a slushy, muddy ocean froze over time. Simulated 12-km-diameter crater showing vertical displacement. (CREDIT: Nature Astronomy) PhD student Ian Pamerleau and assistant professor …

Astronomers discovered the most primitive star ever

Astronomers discovered the most primitive star ever

Published by Jenni Sidey

A dim red giant just out of reach of the Milky Way is providing astronomers with an incredibly rare glimpse into the earliest days of our universe, at a time when it was not possible for a telescope to observe these objects directly. The star SDSS J0715-7334 is located about 80,000 light-years away, and it resides near the Large Magellanic Cloud, a satellite galaxy of the Milky Way. Unlike most red giants, which are known for their large sizes and brilliant brightness, SDSS J0715-7334 is notable for being one of the most chemically primitive (metal-poor) stars discovered. In addition to being composed of nearly entirely hydrogen and helium, with traces of other elements, it contains less than 0.005 percent of the total metallic content of our sun. This star is significant because it has long been theorized that the first stars to form in our universe (Population III stars) were composed almost entirely of hydrogen and helium. Population III stars have never been directly observed, as it is believed that these were very massive stars …

Cassini-Huygens mission finds lopsided shift in Saturn’s magnetic bubble

Cassini-Huygens mission finds lopsided shift in Saturn’s magnetic bubble

Published by Jenni Sidey

Saturn’s magnetic shield does not sit where many scientists would expect. After combing through years of data from the Cassini spacecraft, researchers found that a key opening in Saturn’s magnetosphere, the region where solar wind particles can slip into the planet’s atmosphere, is pushed well away from the noon position seen at Earth. Instead, it tends to sit in the afternoon sector, usually between 13:00 and 15:00 local time, and sometimes stretches as far as 20:00. That skew, the team says, points to a basic difference in how giant planets work. The finding comes from a study in Nature Communications based on Cassini-Huygens mission data collected between 2004 and 2010. The researchers argue that Saturn’s rapid rotation, combined with the heavy plasma supplied largely by its moon Enceladus, reshapes the planet’s magnetic environment in a way that sets it apart from Earth’s more solar-wind-driven system. At Earth, the cusp of the magnetosphere usually lines up near local noon. That is where magnetic field lines bend in a way that allows charged solar particles to funnel …

Giant planet that shouldn’t exist is forcing astronomers to rethink planetary science

Giant planet that shouldn’t exist is forcing astronomers to rethink planetary science

Published by Jenni Sidey

An exoplanet, TOI-5205 b, which is almost as large as Jupiter, orbits a small red star. By many estimates, this red star should not have been able to form it due to the star’s mass. The fact that TOI-5205 b exists as it does at all raises intriguing questions about how it came to be. In addition, the James Webb Space Telescope has confirmed that this planet may be even stranger than previously thought. Specifically, the atmosphere of TOI-5205 b is deficient in heavy elements relative to the hosting star. This discrepancy suggests that the outer layers of the planet and its deep interior have not developed in the same way through the formation process. The findings from the study of TOI-5205 b were recently published in The Astronomical Journal. The research was led by Caleb Cañas, a NASA Goddard Space Flight Center scientist, along with an international team of researchers. This team included Shubham Kanodia, a Carnegie Science astronomer who contributed to the confirmation of the stellar companion in 2023, and who was also …

Four-legged robots look to speed up Mars and Moon exploration

Four-legged robots look to speed up Mars and Moon exploration

Published by Jenni Sidey

The slowest part of a Mars mission is often not the driving, it is the waiting. A rover can only do so much when every move must be planned from Earth, then checked, then sent back across a gap that can stretch communication delays to between four and 22 minutes one way. Moreover, limited data transfer and dangerous terrain make a cautious style of exploration necessary. As a result, rovers may cover only a few hundred meters in a day. A new study suggests there is a faster way to work. In tests at the University of Basel’s Marslabor facility, researchers showed that a semi-autonomous four-legged robot could move to several targets in sequence and deploy instruments on its own. Despite this independence, the robot still returned scientifically useful results for planetary prospecting and the search for signs of past life. Legged robot performing analogue tests in Marslabor at the University of Basel. (CREDIT: Dr Tomaso Bontognali) A robot that does more than wait The robot used in the study was ANYmal, a quadrupedal machine …

Planetary scientists reveal where Earth’s water and building blocks came from

Planetary scientists reveal where Earth’s water and building blocks came from

Published by Jenni Sidey

For years, planetary scientists have argued that some of the material that built Earth must have drifted in from beyond Jupiter, carrying water and other volatile ingredients with it. Estimates often put that outer Solar System share somewhere between 6 percent and 40 percent. A new analysis led by ETH Zurich researchers Paolo Sossi and Dan Bower takes a very different view. After comparing Earth’s isotopic makeup with that of meteorites, Mars and the asteroid Vesta, they argue that Earth formed almost entirely from material already present in the inner Solar System. That does not mean the question is settled. Sossi himself says the debate over Earth’s building blocks is “far from over.” But the new study, published in Nature Astronomy, sharply narrows the room for one popular idea, that large amounts of outer Solar System matter crossed Jupiter’s orbit and became part of the growing Earth. “We were truly astonished to find that the Earth is composed entirely of material from the inner Solar System distinct from any combination of existing meteorites,” Bower said. …

JWST just helped solve Saturn’s mysterious spin problem

JWST just helped solve Saturn’s mysterious spin problem

Published by Jenni Sidey

For years, Saturn made no sense. Measure its rotation rate using radio signals from its aurora and you get one number. Use the planet’s gravity field and you get another. Worse still, the radio-derived rate appeared to be slowly changing over time, which is physically impossible for a planet. A world cannot simply speed up or slow down its spin. Now, using the most powerful space telescope ever built, researchers at Northumbria University have produced the first detailed maps of heat and electrically charged particle distributions across Saturn’s auroral region. What they found explains not just the rotation mystery, but reveals something stranger and more elegant: Saturn’s northern lights are powering a planetary feedback loop that sustains itself through a chain of atmospheric and magnetic interactions. Within This “Mystery”, A Problem The initial explanation of Saturn’s rotation mystery was provided by a 2021 paper co-authored by planetary astronomer and Northumbria professor Tom Stallard. In this study, Stallard and his colleagues demonstrated that the changing radio frequency signal from Saturn’s auroral region was not measuring Saturn’s …

Lightning bolts on Jupiter are up to 100 times stronger than Earth’s

Lightning bolts on Jupiter are up to 100 times stronger than Earth’s

Published by Jenni Sidey

On Jupiter, a storm doesn’t just brew, it can simmer for centuries. The planet’s atmosphere is a perpetual engine of turbulence, and somewhere inside those churning cloud bands, lightning is cracking with a force that dwarfs anything the Earth has ever managed. Just how much force has been, until recently, surprisingly hard to measure. A study published March 20 in the journal AGU Advances by planetary scientist Michael Wong and colleagues at UC Berkeley’s Space Sciences Laboratory finally puts some numbers to it, and the range is staggering. Depending on how you account for the physics of radio emissions across different frequency ranges, bolts on Jupiter could be anywhere from comparable to terrestrial lightning to a million times more powerful. A lull that became an opening The measurement problem was one of noise, not signal. Jupiter’s storms erupt across wide atmospheric bands simultaneously, and when lightning fires from multiple locations at once, pinpointing the source of any given bolt is nearly impossible. Measuring power without knowing where the flash came from is like trying to …

The haziest planet we’ve ever seen won’t give up its secrets

The haziest planet we’ve ever seen won’t give up its secrets

Published by Jenni Sidey

Something is hiding inside Kepler-51d, and it’s doing a remarkably good job of it. About 2,615 light-years away in the constellation Cygnus, this peculiar world orbits a young Sun-like star every 130 days. It’s roughly the size of Saturn. Its mass, however, is only a few times that of Earth, making it so unimaginably light for its size that planetary scientists sometimes compare it to cotton candy. Now, NASA’s James Webb Space Telescope has stared directly at this planet as it crossed in front of its host star, and the result is both a scientific milestone and a profound frustration. The planet is wrapped in the thickest haze ever measured on any world. A study led by Penn State researchers, published in the The Astronomical Journal, found that this haze is so dense and so high in the atmosphere that it effectively blocks all chemical fingerprints beneath it. The team cannot tell what the planet is made of. They cannot determine where it formed. The haze, it turns out, is not just an atmospheric feature. …