Curiosity Blog, Sols 4968-4974: Rock Climbing Towards the Discontinuity

NASA's Mars rover Curiosity acquired this image, a frame of the “Longquimay” mosaic showing fine-scale sedimentary textures in a bedrock block near the supersurface, using its Mars Hand Lens Imager (MAHLI), located on the turret at the end of the rover's robotic arm. Curiosity acquired the image on Aug. 1, 2026 — Sol 4972, or Martian day 4,972 of the Mars Science Laboratory mission — at 23:35:43 UTC.

NASA/JPL-Caltech/MSSS

As mentioned in the previous blog, Curiosity has been exploring a large-scale feature in Gale's sedimentary record suspected to be an “erosional supersurface.” The “supersurface” represents a period in time when a net depositional environment changed to a net erosional one before returning to a depositional regime, thus producing a discontinuity in the rock record. The erosion can involve wind, water, or both. Sometimes there are clues about these environmental changes in the layers below and above the supersurface. So far we've been seeing some patterns that look like aeolian features and also some “lens” deposits that sometimes appear consistent with fluvial origins. We need higher-resolution imaging of these features.

This week Curiosity came within detailed imaging range of a section of the “Cerro Paine Grande” vertical exposure just below the candidate supersurface before climbing on top of it. Mastcam was the star of the show on both planning days this week, capturing large stereo mosaics of the vertical face of the outcrop and a 360-degree panorama after the rover climbed on top of it.

NASA’s Mars rover Curiosity acquired this image, showing the rover arm in action in the “Longquimay” workspace at the top of a steep climb. Curiosity captured the image using its Right Navigation Camera on Aug. 2, 2026 — Sol 4972, or Martian day 4,972 of the Mars Science Laboratory mission — at 00:49:52 UTC.

NASA/JPL-Caltech

Roving to the top took full advantage of Curiosity's climbing capabilities, leaving the rover at an approximate 24-degree tilt in its final parking spot. The rover planners managed to reach the right posture for contact science at the same time — quite a feat, and one that approached the mission’s contact science tilt record of 27 degrees!

Meanwhile, MAHLI and our geochemical instruments provided detailed characterization of the rock layers beneath the discontinuity. I was the Geology and Mineralogy Theme Lead for the Sol 4968 (Monday) planning cycle, during which “Puyehue” in the light-toned bedrock block of the workspace was co-targeted with APXS, MAHLI, and ChemCam LIBS. The other two targeted LIBS observations in the plan went to a similar-looking nearby bedrock block (“Lago Palena”) and an intriguing layered block off to the side of the workspace (“Piedras Juntas”). Another APXS measurement went to a sand target, “Cormudesi,” which will help us assess the consistency of sand compositions along the rover's traverse.

In the Sol 4972 workspace atop the slope, the bedrock was sharply divided between a smooth bedding-parallel surface on the local top of the outcrop and the darker-toned, rougher, angled exposure of the same rocks. The light-toned top surface was measured by MAHLI, APXS, and the LIBS at target "Sierra de Sangre,” whereas the darker-toned laminated face was targeted by APXS and MAHLI at "Laguna del Laja.” The fine-scale sedimentary structures in the textured material were also documented by a MAHLI mosaic (“Longquimay”) supported by Mastcam M100 imaging.

Rounding out the week’s science observations were several long-distance ChemCam RMI mosaics on more distant targets such as sedimentary structures above the rover’s current stratigraphic position, and finally our regular cadence measurements of the modern Martian environment, including atmospheric opacity and a ChemCam passive-sky survey to monitor abundances of minor atmospheric gases 

Written by Lucy Lim, Planetary Scientist at NASA’s Goddard Space Flight Center

Earth planning date: Friday, July 31, 2026 

Source: Curiosity Blog, Sols 4968-4974: Rock Climbing Towards the Discontinuity - NASA Science

Semaglutide Just Slowed the Body’s Aging Clock, And the Trial Wasn’t Even Designed to Test That

Weight-loss drugs like Ozempic and Wegovy already reshaped how obesity and diabetes get treated. Now a new clinical trial is asking a very different question: can the same drug slow down aging itself? According to a peer-reviewed analysis published in Nature Communications in May 2026, the answer is a cautious “maybe” with real numbers, real limitations, and a lot riding on what happens next.

A Trial That Wasn’t Built to Study Aging

The data comes from a 32-week, randomized, double-blind, placebo-controlled phase 2b trial (NCT04019197) of semaglutide in adults with HIV-associated lipohypertrophy, an abnormal buildup and redistribution of body fat, especially visceral fat around the organs, linked to both HIV infection and some of its treatments. 45 participants received semaglutide and 39 received a placebo. The trial’s actual goal was to measure change in visceral fat, with cardiometabolic and body-composition changes as secondary outcomes. Biological aging was never part of the original plan.

After the trial ended, a separate team went back to the stored blood samples, drawn at the start and at week 32, and ran them through a set of tools called epigenetic clocks, to see, retroactively, whether semaglutide had done anything to the pace of aging along the way.

What an Epigenetic Clock Actually Measures

Your chronological age is just a count of years. Your biological age is an estimate of how worn down your cells actually are, and it doesn’t always match the calendar. Epigenetic clocks estimate biological age by reading DNA methylation, chemical tags attached to DNA that switch genes on or off and shift in predictable patterns as the body ages and accumulates damage.

Older, “first-generation” clocks were built simply to predict chronological age from a blood sample. Newer second- and third-generation clocks, names like PhenoAge, GrimAge, and DunedinPACE, are trained instead on health outcomes and mortality risk, which is what makes them useful here: they’re trying to capture how fast someone is aging, not just how old they are.

The Numbers

In adjusted analyses comparing semaglutide to placebo, the drug was associated with slower readings across several of these clocks:

·         PhenoAge: –4.9 years/year (p = 0.004)

·         PCGrimAge: –3.1 (p = 0.007)

·         GrimAge V2: –2.3 (p = 0.009)

·         OMICmAge: –2.2 (p = 0.009)

·         RetroAge: –2.2 (p = 0.030)

·         DunedinPACE: –0.09 units, roughly a 9% slower pace of aging (p = 0.01)

Beyond the whole-body clocks, systems-based measures also showed parallel reductions in estimated inflammation, brain, and heart aging – suggesting the effect, if real, isn’t confined to one organ system.

Why This Isn’t Proof Yet

The authors themselves are explicit about the limits here, and they’re worth taking seriously rather than skipping past:

·         This was a post hoc, exploratory analysis, the aging measurements were never pre-specified as something the trial was testing, which raises the risk of chasing a pattern that partly reflects chance.

·         The sample was small: 84 people total, split across two arms.

·         Everyone in the trial had HIV-associated lipohypertrophy, a specific condition with its own inflammatory and metabolic profile, so the results may not carry over to people without HIV or without that fat-redistribution pattern.

·         Follow-up lasted only 32 weeks, far too short to say anything about long-term outcomes like lifespan or age-related disease.

·         Two of the authors are employed by the company that makes one of the epigenetic clock tests used in the analysis, a disclosed competing interest worth factoring in when weighing how the results are framed.

The researchers’ own conclusion is measured: this is early evidence that GLP-1 drugs might be worth studying as “gerotherapeutics”,  treatments aimed at the aging process itself, not just one disease, and that prospective trials, designed from the start to test aging, are needed before anyone can say more.

The Bigger Picture

Semaglutide has already moved well beyond weight loss in the research world; separate large trials have tied it to cardiovascular benefits independent of weight change. This new analysis doesn’t prove the drug slows human aging. What it does is give researchers a real, human, randomized-trial signal, something to build a properly designed study around, rather than a reason to treat a GLP-1 prescription as an anti-aging plan.

Sources

·         Corley, M.J., Dwaraka, V.B., Pang, A.P. et al. “Semaglutide slows epigenetic aging in a randomized trial of HIV-associated lipohypertrophy.” Nature Communications, 2026. nature.com/articles/s41467-026-72861-3

·         “Popular weight-loss drugs Ozempic and Wegovy may slow biological aging.” ScienceDaily, July 2026. sciencedaily.com

·         “Semaglutide and aging: New study finds benefits beyond weight loss.” Medical News Today. medicalnewstoday.com

This post summarizes a single clinical study and is general science information, not medical advice. Talk to a healthcare provider before making any decisions about GLP-1 medications.

Source: Semaglutide Just Slowed the Body’s Aging Clock, And the Trial Wasn’t Even Designed to Test That