Study Findings: Carbonate Formation and Fluctuating Habitability on Mars

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Image (Credit): Mars as captured by NASA Mars Global Surveyor MOC wide angle cameras. (NASA/JPL/MSSS)

Nature abstract of the study findings:

The cause of Mars’s loss of surface habitability is unclear, with isotopic data suggesting a ‘missing sink’ of carbonate. Past climates with surface and shallow-subsurface liquid water are recorded by Mars’s sedimentary rocks, including strata in the approximately 4-km-thick record at Gale Crater. Those waters were intermittent, spatially patchy and discontinuous, and continued remarkably late in Mars’s history—attributes that can be understood if, as on Earth, sedimentary-rock formation sequestered carbon dioxide as abundant carbonate (recently confirmed in situ at Gale). Here we show that a negative feedback among solar luminosity, liquid water and carbonate formation can explain the existence of intermittent Martian oases. In our model, increasing solar luminosity promoted the stability of liquid water, which in turn formed carbonate, reduced the partial pressure of atmospheric carbon dioxide and limited liquid water. Chaotic orbital forcing modulated wet–dry cycles. The negative feedback restricted liquid water to oases and Mars self-regulated as a desert planet. We model snowmelt as the water source, but the feedback can also work with groundwater as the water source. Model output suggests that Gale faithfully records the expected primary episodes of liquid water stability in the surface and near-surface environment. Eventually, atmospheric thickness approaches water’s triple point, curtailing the sustained stability of liquid water and thus habitability in the surface environment. We assume that the carbonate content found at Gale is representative, and as a result we present a testable idea rather than definitive evidence.

Citation: Kite, E.S., Tutolo, B.M., Turner, M.L. et al. Carbonate formation and fluctuating habitability on Mars. Nature 643, 60–66 (2025).

https://doi.org/10.1038/s41586-025-09161-1

Study-related stories:

University of Chicago – “Was Mars Doomed to be a Desert? Study Proposes New Explanation”

Science Alert – “NASA Discovery Could Explain Why We’ve Never Found Life on Mars”

The Register – “Mars Was Once a Desert with Intermittent Oases, Curiosity Data Suggests”

Study Findings: The Influence of Passing Field Stars on the Solar System’s Dynamical Future

Posted on by onespaceman2000
Credit: Image by Yol Gezer from Pixabay.

Icarus abstract of the study findings:

The long-term dynamical future of the Sun’s planets has been simulated and statistically analyzed in great detail, but most prior work considers the solar system as completely isolated, neglecting the potential influence of field star passages. To understand the dynamical significance of field star encounters, we simulate several thousand realizations of the modern solar system in the presence of passing field stars for 5 Gyrs. We find that the impulse gradient of the strongest stellar encounter largely determines the net dynamical effect of field stars. Because the expected strength of such an encounter is uncertain by multiple orders of magnitude, the possible significance of field stars can be large. Our simulations indicate that isolated models of the solar system can underestimate the degree of our giant planets’ future secular orbital changes by over an order of magnitude. In addition, our planets and Pluto are significantly less stable than previously thought. Field stars transform Pluto from a completely stable object over 5 Gyrs to one with a ∼5% instability probability. Furthermore, field stars increase the odds of Mercury’s instability by ∼50%–80%. We also find a ∼0.3% chance that Mars will be lost through collision or ejection and a ∼0.2% probability that Earth will be involved in a planetary collision or ejected. Compared to previously studied instabilities in isolated solar systems models, those induced by field stars are much more likely to involve the loss of multiple planets. In addition, they typically happen sooner in our solar system’s future, making field star passages the most likely cause of instability for the next 4–4.5 Gyrs.

Citation: Kaib, Nathan A. and Raymond, Sean N., The influence of passing field stars on the solar system’s dynamical future, Icarus (2005).

https://doi.org/10.1016/j.icarus.2025.116632

Study-related stories:

The New York Times

Science News

Planetary Science Institute

Pic of the Week: Mars or Bust?

Posted on by onespaceman2000
Image (Credit): The explosion of a Starship rocket during testing at the Brownsville, Texas Starbase on June 18, 2025. (LabPadre Space)

As shown in the image above, SpaceX lost one of its Starships yesterday in a massive explosion at the Brownsville, Texas Starbase, making the Moon and Mars seem even farther away. Fortunately, no one was injured during this failed test firing of the Starship 36 rocket engines.

We should expect some problems along the way, but the trend is going backwards for Mr. Musk.

In a press release, SpaceX stated:

Engineering teams are actively investigating the incident and will follow established procedures to determine root cause. Initial analysis indicates the potential failure of a pressurized tank known as a COPV, or composite overwrapped pressure vessel, containing gaseous nitrogen in Starship’s nosecone area, but the full data review is ongoing. There is no commonality between the COPVs used on Starship and SpaceX’s Falcon rockets.

In separate comments, Mr. Musk initially stated:

Just a scratch.

Yes, the scratch heard round the world.

Space Stories: Newly Discovered Volcano on Mars, Universe’s Missing Matter Found, and Congress Expects a NASA Nominee

Posted on by onespaceman2000
Image (Credit): View of the rim of Jezero Crater from NASA’s Perseverance Mars rover on December 10, 2024. (NASA/JPL-Caltech)

Here are some recent space-related stories of interest.

—Georgia Tech: “Volcano ‘Hidden in Plain Sight’ Could Help Date Mars — and its Habitability“

Georgia Tech scientists have uncovered evidence that a mountain on the rim of Jezero Crater — where NASA’s Perseverance Rover is currently collecting samples for possible return to Earth — is likely a volcano. Called Jezero Mons, it is nearly half the size of the crater itself and could add critical clues to the habitability and volcanism of Mars, transforming how we understand Mars’ geologic history. The study, “Evidence for a composite volcano on the rim Jezero crater on Mars,” was published this May in the Nature-family journal Communications Earth & Environment, and underscores how much we have left to learn about one of the most well-studied regions of Mars.

—Caltech: “Missing Matter in Universe Found“

Due to its diffuse nature, roughly half of ordinary matter in the universe went unaccounted for and had been considered “missing”—until now. In a new study in Nature Astronomy, a team of astronomers at Caltech and the Center for Astrophysics | Harvard & Smithsonian (CfA) has, for the first time, directly detected and accounted for all the missing matter. To do this, the team used brief, bright radio flashes in the distant cosmos, called fast radio bursts (FRBs), to illuminate the matter lying between the FRBs and us. “The FRBs shine through the fog of the intergalactic medium, and by precisely measuring how the light slows down, we can weigh that fog, even when it’s too faint to see,” says Liam Connor, assistant professor at Harvard and lead author of the study, who performed much of the work while a Caltech research assistant professor working with Vikram Ravi, assistant professor of astronomy at Caltech.

—Space News: “Members of Congress Want White House to Quickly Nominate New NASA Administrator“

Members of the House and Senate called in the White House to promptly offer a new candidate for NASA administrator after the surprise withdrawal of Jared Isaacman’s nomination. In briefings organized by the Aerospace Industries Association June16, representatives of House and Senate delegations to the Paris Air Show said it was critical that the agency get permanent leadership as it deals with potential significant cuts to its budget in the coming fiscal year.

Budget Cuts: A Graphic Portrayal of the NASA Betrayal

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Image (Credit): Graphic showing NASA missions either eliminated (red x) or severely cut (red !) in the most recent White House budget request. (Astronomy Magazine)

Astronomy magazine did us all a great service by clearly demonstrating the impact of the White House’s FY 2026 budget request on NASA space missions.

In a graphic covering the solar system and everything else, you can visualize for yourself the enormous impact of the proposed cuts. Very few programs are safe, including those we share with the European Space Agency (ESA) and others. In fact, only the “Biological and Physical” missions (shown in orange) seem to be mostly untouched.

For example, under “Planetary” missions (shown in purple), we see the end of:

Some of this may have made sense if there was a good discussion of existing missions and a thoughtful process to wind some of them down. But that is not how this White House works, and we are all the poorer for it.

In addition to many in NASA and the public at large, some in Congress are pushing back on these excessive losses. This is still somewhat early in the budget process for FY 2026, but did anyone really expect this to be the starting point in NASA’s budget discussions?

The greatest space agency in the world is being hacked to pieces, along with many other US scientific programs. The costs will be felt for generations to come. Just as Apollo helped to lift a nation, these cuts are designed to harm that legacy and ultimately the nation.

Note: If you cannot see the image clearly here, you can go to this link.