Tag Archives: warmer

Mars Was Once Warmer and Wetter, Say Planetary Scientists

Posted on by
Reply

NASA’s Perseverance spacecraft has identified thousands of light-toned rock fragments, also known as floating rocks, several of which exhibit spectral characteristics of an aluminum-rich clay mineral known as kaolinite. To understand their origins, planetary scientists utilized data from Perseverance’s SuperCam and Mastcam-Z instruments to analyze the chemistry and reflectance spectra of the floating rocks in relation to deeply weathered paleosols (ancient soils) and hydrothermal kaolin deposits recorded in Earth’s geological archives. The increased levels of aluminum and titanium, along with the reduced amounts of iron and magnesium, differentiate these rocks from hydrothermal deposits, aligning them more closely with the bleached layers of paleosoils formed during periods of significant rainfall in Earth’s past greenhouse climates. Thus, these rocks may signify some of the most aqueous periods in Mars’ history.

Mastcam-Z landscape and multispectral images of light-toned float rocks atop the Jezero Crater Margin Unit near the Hans Amundson Memorial Works (Sol 912). It shows the spectral diversity of this material. Image credit: Broz others., doi: 10.1038/s43247-025-02856-3.

“Rocks like these are likely among the most significant outcrops we’ve observed from orbit because their formation is challenging to replicate elsewhere on Mars,” stated Dr. Bryony Hogan, Perseverance’s long-term planner and a researcher at Purdue University.

“Given that these require substantial water, we believe they could be indicative of an ancient, warmer, wetter climate that experienced prolonged periods of rainfall.”

“Tropical environments, such as rainforests, are where kaolinite clays are predominantly found on Earth,” added Adrian Broz, Ph.D., a postdoctoral researcher at Purdue University.

“Thus, when finding kaolinite on Mars, which is desolate and frigid with no surface liquid water, it suggests that there used to be significantly more water than is present today.”

Kaolinite fragments, varying in size from pebbles to larger rocks, contribute to the ongoing discussion about the climate of Mars billions of years ago.

Initial analyses using the SuperCam and Mastcam-Z instruments have involved comparing kaolinite to analogous rocks on Earth.

Debris from Mars could yield crucial insights into not only the planet’s historical environmental conditions but also how it transitioned to its current desolate state.

“Kaolinite carries its own enigmas,” emphasized Dr. Hogan.

“Currently, there are no significant outcrops nearby that could explain the presence of these light-colored rocks, despite their distribution along the mission’s path since Perseverance’s landing in Jezero Crater in February 2021.”

“This crater once housed a lake that was approximately twice the size of Lake Tahoe.”

“While there are compelling indicators of significant water events, the origin of these rocks remains uncertain.”

“It’s possible they were transported into the Jezero lake by rivers that formed the delta regions, or they may have been ejected into Jezero by a meteorite impact. The complete picture is still unclear.”

Satellite imaging has revealed substantial kaolinite outcrops in various regions of Mars.

“However, until we can physically reach these large outcrops with spacecraft, these small rocks are the only tangible evidence we have regarding their formation,” Dr. Hogan noted.

“Currently, the findings in these rocks suggest a historically warmer and wetter environment.”

Mastcam-Z and SuperCam observations of hydrated layers of aluminum-rich floating rock in Jezero Crater, Mars. Image credit: Broz others., doi: 10.1038/s43247-025-02856-3.

The researchers compared the Martian kaolinite samples studied by Perseverance to rock samples located near San Diego, California, and in South Africa. The similarities between the rocks from both planets were striking.

On Earth, kaolinite forms in both rainy tropical climates and hydrothermal systems where hot water permeates into rocks.

Nonetheless, this process leaves behind chemical signatures that differ from the effects of cold leaching from rain over extended periods.

Scientists evaluated various hydrothermal leaching scenarios against Martian rocks using datasets from three distinct sites.

Rocks like kaolinite from Mars act as time capsules, potentially preserving billions of years of information regarding environmental conditions throughout Earth’s history.

“All life requires water, so if these Martian rocks signify a rainfall-driven environment, that’s an extraordinary indication of a potentially habitable space where life could have flourished on Mars,” stated Dr. Broz.

The team’s paper has been published in the journal Communication Earth and Environment.

_____

AP Broz others. 2025. Alteration history of aluminum-rich rocks in Mars’ Jezero Crater. Communication Earth and Environment 6,935; doi: 10.1038/s43247-025-02856-3

Source: www.sci.news

The Sun’s Coldest Regions Are Surprisingly Warmer Than Anticipated – Fool

Posted on by
Reply

The sun serves as a fundamental source of heat and light in the solar system, with its energy generated in the core through the collision of hydrogen ions and helium. Nuclear Fusion. Consequently, while the surface temperature of the sun is extremely hot by Earth’s standards—approximately 10,000°F or 5,600°C—it is relatively cooler compared to the center, which reaches around 27,000,000°F or 15,000,000°C.

Heat and light travel from the sun’s center to its surface via two main processes: one is similar to how the sun heats the Earth, known as radiation. Here, energy moves outward through light particles, or photons. Conversely, heat transfer occurs on Earth through the process of convection, with cold gas descending while warm gas rises. This creates a swirling motion within the sun, where hot gases near the core move upward and cooler gases sink back down.

A diagram of the sun illustrating how convection and radiation influence heat movement at different depths. “Sun poster” by Kelvinsong is licensed under CC by-sa 3.0.

The interplay of radiation, convection, and the sun’s varying rotational speeds based on distance from the equator results in uneven heating of the solar surface, leading to both hot and cold areas. While scientists have a grasp of this general pattern, discrepancies exist between models predicting solar surface temperatures and observed data. The model estimates a temperature of around 2,000 Kelvin (k), translating to approximately 3,100°F or 1,700°C for the coldest sections, yet actual findings indicate these regions are around 4,000k, or about 6,700°F or 3,700°C.

This paradox highlights the challenges in understanding heat transfer within the sun. Several unknown factors may lead to the observed discrepancy of over 1,000k in the coldest spots. A team of researchers investigated one possible explanation for the missing heat by conducting both two-dimensional and three-dimensional simulations. They hypothesized that when convection separates neutral charged gases from the sun’s center, negatively charged electrons are driven by a magnetic field near the sun’s surface, generating additional heat. This phenomenon is referred to as Thermal Farley-Bnemann’s instability, or TFBI Turbulence.

The team employed two computer programs, ebysus and Epic, to simulate these cold bubbles in the outer layer of the sun, known as the Chrome area, over a span of 8-10 milliseconds. They incorporated variables such as material density, magnetic field strength, and collision frequency into their simulations. The TFBI turbulence was then integrated into the 2D ebysus model, which was compared with heating observed in the EPPIC simulations in both 2D and 3D.

The primary distinction between the programs lies in how they treat gas: ebysus models it as a swirling liquid, facilitating easier movement calculations, while Epic views it as a collection of bouncing particles that generate electromagnetic fields, complicating calculations. They conducted five simulations: one in 2D with EBYSUS, which was the fastest yet potentially the least accurate, one in 2D with Epic, which was slower but arguably more realistic, and two in 3D with EPPIC, which, while the slowest, yielded the most accurate outcomes.

The results from their 2D simulations indicated that turbulent heating could increase temperatures in cold regions by over 700,000. Similar findings were observed in the 3D simulations as well. The team contended that their simulations demonstrated how turbulence from the TFBI could augment heat in the sun’s cooler areas beyond what convection and radiation contribute. Nonetheless, they recommended that future research extend over longer time frames to fully grasp the implications of these processes. Additionally, comparisons between 2D and 3D simulations suggest that scientists can effectively investigate this phenomenon using quicker 2D fluid models, achieving results comparable to more complex and resource-intensive 3D particle models.


Post view: 46

Source: sciworthy.com

Uranus May Be Warmer Than Previously Thought

Posted on by
Reply

Recent studies published in the journal reveal that Uranus emits approximately 15% more energy than it receives from the Sun, as documented in Monthly Notices from the Royal Astronomical Society and Geophysical Research Book.

Composite image of Uranus. Image credit: Marcos Van Dam/Wm Keck Observatory.

Uranus distinguishes itself from other planets in our solar system by rotating on its side, causing each pole to face the Sun for 42 consecutive years during its “summer.”

This planet also rotates in a direction opposite to all other planets except Venus.

Data from the 1986 Voyager 2 flyby mission showed that Uranus has an unusually cold interior, prompting scientists to reconsider how the planet formed and its evolution within the solar system.

“Since the Voyager 2 flyby, there’s been an assumption that Uranus lacks internal heat,” said Dr. Amy Simon, a planetary scientist and co-author from NASA’s Goddard Space Flight Center. First paper.

“However, explaining this has been challenging, particularly when compared to other giant planets.”

“The data regarding Uranus’s heat emissions originated from a single measurement made during the Voyager 2 mission,” Dr. Simon noted. “This reliance on one data point created a significant challenge.”

Through advanced computer modeling and analysis of decades of data, Dr. Simon and her colleagues discovered that Uranus does, in fact, generate internal heat.

To understand a planet’s internal heat, scientists compare the energy it receives from the Sun to the energy it radiates back into space as reflected light and emitted heat.

Other giant planets like Saturn, Jupiter, and Neptune emit more heat than they receive, suggesting that the excess heat originates from within.

The rate at which a planet releases heat can indicate its age; a planet that emits less heat than it absorbs is generally considered older.

Because Uranus was believed to emit an equal amount of heat to what it received, it was initially thought to lack internal heat.

This discrepancy puzzled scientists, leading them to speculate that Uranus might be significantly older than its neighbors, having completely cooled over time.

Some hypotheses suggested that a massive impact (possibly the same event that tilted the planet) may have stripped Uranus of its internal heat.

However, these theories did not satisfy researchers, motivating them to investigate what they termed the “Uranus cold case.”

“Did we mistakenly believe that Uranus has no internal heat?” asked Professor Patrick Irwin from Oxford University, the lead author of the first paper.

“We conducted extensive calculations to evaluate how much sunlight is reflected by Uranus, only to realize that it is actually more reflective than previously estimated.”

Researchers aimed to assess Uranus’s overall energy budget, exploring the total energy received from the Sun, the light reflected, and the heat emitted.

This required calculating the total light reflected from the planet from various angles.

“We need to consider light scattered across the planet’s surface instead of just direct reflections,” Dr. Simon explained.

To provide the most accurate energy budget estimate for Uranus, scientists created a computer model incorporating all available data on Uranus’s atmosphere from decades of ground- and space-based observations, including data from the NASA/ESA Hubble Space Telescope and NASA’s infrared telescope in Hawaii.

This model accounts for factors like haze, cloud cover, and seasonal changes that influence how sunlight is reflected and heat escapes.

The findings reveal that Uranus emits about 15% more energy than it receives from the Sun, as reported in a second study.

These investigations suggest that Uranus possesses its own internal heat but emits more than twice the energy it receives, although still less than its neighbor, Neptune.

“Now we need to delve deeper into what the additional heat on Uranus signifies and improve our measurement techniques,” Dr. Simon concluded.

____

Patrick GJ Irwin et al. 2025. Uranus’ bolometric binding albedo and energy balance. mnras 540(2): 1719-1729; doi: 10.1093/mnras/staf800

XINYUE WANG et al. 2025. Uranus’ internal heat flux and energy imbalance. Geophysical Research Book 52 (14): E2025GL115660; doi: 10.1029/2025GL115660

Source: www.sci.news

Half the Month Is Warmer Than All the Other Months

Posted on by
Reply

Map illustrating anomalies in the lunar gravity field derived from data obtained by NASA’s GRAIL mission

NASA/JPL-CALTECH/MIT/GSFC

Research indicates that the moon’s gravitational pull suggests a warm, dense interior, hinting at structural irregularities beneath its surface.

The distinct appearance of the moon’s near side compared to its far side has intrigued observers since time immemorial. However, it raises questions about whether these differences provide insights into the deeper layers of the moon, as stated by Ryan Park from NASA’s Jet Propulsion Laboratory in California. Together with his colleagues, he is utilizing data from NASA’s GRAIL spacecraft to investigate.

The GRAIL mission gathered crucial data on the moon’s gravitational variations during 2011 and 2012, while two spacecraft orbited the lunar body. Since the gravity field is reflective of physical characteristics, researchers were able to analyze how it deforms based on both the moon’s shape and Earth’s tidal forces.

Despite this, the variations in the gravity field could not solely be accounted for by the observable features of the moon’s surface. Scientists contemplated the possibility of a heterogeneous interior. Previous findings suggested that the moon’s near side would exhibit more deformation compared to the far side due to Earth’s gravitational influence, as noted by Jeffrey Andrews-Hanna from the University of Arizona. This recent research validates that assertion, enabling a deeper understanding of the moon’s structure.

Using GRAIL data, Park and the team calculated that the moon’s susceptibility to Earth’s gravitational pull was 72% higher than what would be expected if the moon’s interior were entirely uniform.

The research team examined various factors contributing to this anomaly, including the moon’s chemical makeup. However, the model that closely aligned with the observed data was one indicating a temperature variation, suggesting that the moon’s interior is warmer than the far side.

Sean Solomon from Columbia University in New York noted that this model aligns with existing knowledge about the moon’s volcanic history and the distribution of radioactive elements, such as uranium and thorium, on its surface.

While the exact reasons for the moon’s irregular interior remain uncertain, Park suggests that some of these variations may result from its turbulent history of impacts with other celestial bodies. Moving forward, he and his team aim to utilize seismic data from lunar quakes to further explore the moon’s internal structure. These data will be gathered by the Far Side Earthquake Suite, which NASA plans to deploy in 2026.

Topic:

Source: www.newscientist.com