ERIK MARTIN WILLÈN: August 2026

Saturday, August 1, 2026

What's Up: August 2026 Skywatching Tips from NASA - NASA Jet Propulsion Laboratory

A solar eclipse, the Perseids, bright Venus after sunset, and a deep partial lunar eclipse highlight August's skywatching.

Skywatching Highlights

Aug. 5: Last Quarter Moon
Aug. 12: Total solar eclipse across northern Russia, Greenland, Iceland, northern Spain, and part of Portugal; partial eclipse in parts of the U.S.; New Moon
Aug. 12-13: Perseid meteor shower peak under dark skies
Aug. 14-16: Venus reaches greatest eastern elongation and shines low in the west after sunset
Aug. 27-28: Partial lunar eclipse visible from much of North and South America and parts of Europe and Africa

Transcript

A solar eclipse, one of the year's best meteor showers, Venus at its brightest in the evening sky, and a lunar eclipse to close out the month.

That's “What’s Up” for August.

On Aug. 12, a total solar eclipse crosses northern Russia, Greenland, Iceland, and northern Spain, with a small corner of Portugal inside the path of totality.

In parts of the United States, from Alaska to North Carolina, the eclipse is partial. The Moon will take only a small bite out of the Sun, and the amount of coverage will vary with location.

A map showing viewing areas of the August 2026 total solar eclipse.

NASA/JPL-Caltech

Remember to watch safely. Use certified eclipse glasses or a safe solar viewer any time any part of the Sun is visible. Regular sunglasses are not safe. And never use binoculars, a telescope, or a camera without a solar filter made for the front of the optics.

Later that same night, the Perseid meteor shower will light up the sky, peaking the evening of Aug. 12 into the early morning hours of the 13th. And with a New Moon arriving on the 12th, the skies will be ideally dark.

The Perseids happen every year when Earth passes through a debris stream left behind by Comet Swift-Tuttle. As those tiny bits of comet dust hit our atmosphere at high speed, they burn up as bright streaks of light.

To view this meteor shower, look toward the northeast once it's fully dark and watch for the constellation Perseus to clear the horizon. This is where the meteors originate, but let your eyes wander, because they can flash across any part of the sky.

For the best view, stay out late as the stars climb higher, find a dark open spot, and give your eyes 30 minutes to adjust.

This illustration shows where in the night sky to look for the Perseid meteor shower.

NASA/JPL-Caltech

Aug. 14-16, Venus reaches its greatest eastern elongation, which is its widest apparent separation from the Sun during this evening appearance.

Look low in the western sky shortly after sunset for the bright object that will outshine every star around it. Through a telescope after sunset, Venus will look close to half lit, like a tiny lunar phase.

This illustration shows where to observe Venus after sunset in August.

NASA/JPL-Caltech

On the night of Aug. 27, continuing into Aug. 28 for some time zones, the Full Moon slips through Earth's shadow, resulting in a partial lunar eclipse. It will be visible from much of North and South America and parts of Europe and Africa.

Viewing areas for the August 2026 lunar eclipse.

NASA/JPL-Caltech

At maximum eclipse, about 93% of the Moon's diameter will be inside Earth's dark central shadow, called the umbra. The Moon will not be completely covered, but it can look dramatically darkened, with a rusty, coppery tint along the covered edge.

Unlike a solar eclipse, a lunar eclipse is safe to watch with just your eyes. Binoculars or a small telescope can give you a closer view of Earth's curved shadow moving across the Moon.

Here are the phases of the Moon for August.

NASA/JPL-Caltech

You can stay up to date on all of NASA's missions exploring the solar system and beyond at science.nasa.gov. I'm Raquel Villanueva from NASA's Jet Propulsion Laboratory, and that's What's Up for this month.

Source: What’s Up: August 2026 Skywatching Tips from NASA - NASA Science

How Your Body’s Own Recycling System Could Calm Inflammation Without Weakening Immunity

Most anti-inflammatory drugs work the same way: they turn down the immune system as a whole, which calms the flare-up but also leaves patients more vulnerable to infection. Researchers at VIB and KU Leuven, working with international collaborators, have found a way around that trade-off. By targeting a specific type of blood vessel rather than immune cells themselves, they were able to reduce inflammation in mice with psoriasis while leaving the rest of the immune system untouched. The findings, published in Immunity, point to a promising new route for treating chronic inflammatory and autoimmune disease.

The vessels that decide who gets into the lymph nodes

Lymph nodes are the immune system’s checkpoints, filtering lymph and blood for pathogens and coordinating the response against them. Immune cells reach the lymph nodes through specialized blood vessels called high endothelial venules, or HEVs. These vessels are studded with adhesion molecules known as peripheral node addressins (PNAd), which act like a sticky coating that pulls circulating lymphocytes out of the bloodstream and into the node.

First author Dr Kathryn Jacobs (VIB-KU Leuven) describes PNAd as the signal that tells immune cells to leave the bloodstream and enter the lymph node.

Cellular recycling keeps the gates open

During infection, HEVs ramp up PNAd production to pull in more lymphocytes and strengthen the immune response, but in chronic inflammatory and autoimmune disease, that same mechanism keeps immune cells flooding in long after they’re needed, worsening symptoms. What controls PNAd production had remained largely a mystery.

The team, led by Prof Gabriele Bergers at the VIB-KU Leuven Center for Cancer Biology, traced it back to autophagy: the cell’s internal recycling process for clearing out old or damaged components. When the researchers blocked autophagy specifically in HEVs, PNAd production dropped, the vessels lost their specialized identity, and far fewer lymphocytes were able to enter the lymph nodes. Notably, blocking autophagy in other blood vessel types has the opposite effect, ramping inflammation up rather than down — a sign that HEVs handle autophagy in a distinct way.

Testing the idea in psoriasis

To see whether disrupting HEVs could treat disease without touching the immune system directly, the team turned to psoriasis, a chronic autoimmune skin condition affecting an estimated 125 million people worldwide. HEVs can form within psoriatic skin lesions, where they recruit immune cells and keep local inflammation going. Existing treatments mostly work by suppressing immunity broadly, which raises the risk of serious infection.

In a mouse model of psoriasis, blocking autophagy in HEVs cut immune cell recruitment and reduced skin inflammation. The researchers then tested a pharmacological approach: a drug that blocks a signaling receptor HEVs need to form and function. It reproduced the same effect, lowering both immune cell infiltration and inflammation.

Prof Gabriele Bergers says the results point to HEVs as a promising therapeutic target, though more work is needed before the approach could reach patients.

What’s next

The team hopes to refine the LTβR-blocking drugs used in the study. A better antagonist, Dr Jacobs suggests, could potentially help with a range of autoimmune diseases beyond psoriasis — dialing down the immune response without disarming the immune cells that patients still need for everyday protection.

Original paper: Autophagy maintains high endothelial venule identity and function during inflammation, published in Immunity (DOI: 10.1016/j.immuni.2026.06.020).

Source: How Your Body’s Own Recycling System Could Calm Inflammation Without Weakening Immunity

The One-Eyed Ancestor Behind Your Vision, and Your Sleep Cycle

Look in the mirror, and you’re looking at the descendants of a one-eyed ancestor. According to a new evolutionary review in Current Biology, the strange architecture of the vertebrate eye, and even the light-sensing gland buried deep in your brain, traces back to a tiny, worm-like creature that lived nearly 600 million years ago and had just a single eye on top of its head.

The study, led by researchers at the University of Sussex and Lund University, doesn’t report a new fossil. Instead, it pieces together clues from comparative anatomy, developmental biology, and cell-type evolution across many living animals to reconstruct a plausible sequence of events explaining why vertebrate eyes look so radically different from the eyes of insects, squid, and virtually everything else.

Why vertebrate eyes are weird

Across the animal kingdom, most light-sensing systems are built the same way: photoreceptor cells sit in the skin on the sides of the head, wired directly into simple nerves. That’s true for insects, squid, and most other invertebrates with eyes.

Vertebrates broke that mold entirely. Our retinas combine two fundamentally different photoreceptor lineages, rod and cone cells on one hand, and ganglion, amacrine, and horizontal cells on the other, layered together in a complex circuit that actually develops out of brain tissue rather than skin. That’s a big part of why the vertebrate retina behaves less like a simple light sensor and more like an extension of the brain itself, complete with its own image-processing circuitry before signals ever reach the rest of the nervous system.

Explaining how such an unusual arrangement evolved has been a long-standing puzzle. This new review offers a surprising answer: it didn’t evolve from paired lateral eyes at all. It evolved from a single eye in the middle of the head.

Meet the cyclops

The researchers propose that our very distant ancestor, a small, sedentary, worm-like animal that fed by filtering plankton from seawater, once had paired light-sensing structures on either side of its head, as is common throughout the animal kingdom. But because it had settled into a stationary, filter-feeding lifestyle, it no longer needed to actively judge direction, distance, or the location of predators and prey. Over many generations, those paired eyes were lost.

What the animal kept was a patch of light-sensitive cells along the midline of its head. Rather than forming detailed images, this simple median eye likely served a more basic function: distinguishing night from day and sensing which way was up, both useful things to know even for an animal that never moved.

How the eyes came back, rebuilt from scratch

Later, descendants of this creature returned to an actively swimming lifestyle, bringing back the old evolutionary pressure to see clearly: to spot food, obstacles, predators, and direction of travel. According to the researchers, evolution didn’t rebuild new lateral eyes from scratch or resurrect the old, lost ones. Instead, it repurposed pieces of the median eye, splitting and reorganizing it into the paired, image-forming retinas that vertebrates carry today.

That evolutionary shortcut, reusing existing tissue rather than building fresh structures, would explain why the vertebrate retina develops from brain tissue instead of skin: the median eye it came from was already positioned and wired that way. It may also explain a much more specific and unusual detail of the retina’s construction, bipolar cells, which relay signals from photoreceptors deeper into the neural circuit. The researchers argue these cells have two separate evolutionary origins: some descend from a lineage of ciliary “effector” cells, while the light-sensitive, “on”-type bipolar cells appear to trace back to a hybrid, or chimeric, sensory cell type. That dual origin would be a very strange thing to find if the retina had evolved by a single, straightforward path, but it fits neatly with a story of repurposed, patchwork tissue.

The eye you didn’t know you still have

Perhaps the most striking part of the proposal is what happened to the leftover pieces of the original median eye that weren’t repurposed into the retina. The researchers argue they didn’t disappear. Instead, they became the pineal gland, the small, light-sensitive structure buried deep in the vertebrate brain.

In many living vertebrates, such as lizards and frogs, the pineal complex is still directly sensitive to light, sometimes visible as a literal “third eye” spot on top of the head. In mammals, including humans, the pineal gland no longer forms images or directly senses light. But it still governs the circadian rhythm, producing melatonin in patterns tied to the day-night cycle, using light information relayed to it indirectly through the eyes. Under this new model, the reason your sleep cycle answers to daylight at all is a direct evolutionary echo of a light-sensing organ that a one-eyed ancestor carried on the top of its head some 600 million years ago.

The researchers frame the work as reconstructing how vertebrate retinal neurons and their circuits first arose, an account that also explains the deep cell-type similarities between the retina and the pineal gland, two organs that, on the surface, do very different jobs.

Source: G. Kafetzis, M.J. Bok, T. Baden, and D.-E. Nilsson, “Evolution of the vertebrate retina by repurposing of a composite ancestral median eye,” Current Biology, Vol. 36, Issue 4, R153-R170 (2026). Read the full paper: https://www.cell.com/current-biology/fulltext/S0960-9822(25)01676-8

Source: The One-Eyed Ancestor Behind Your Vision, and Your Sleep Cycle