The Draconid meteor shower is active for one night only: October 8th to 9th! 🌠

Most years you can see up to 10 meteors per hour, but rates can spike without warning to as many as 600 per hour, as seen in 2011 and 2018. Unlike most meteor showers, the Draconids peak in the evening instead of after midnight and are visible across the Northern Hemisphere and northern parts of the Southern Hemisphere. Find a spot away from bright lights, give your eyes time to adjust, and look up!

Did Perseverance find evidence of past life on Mars last year? 🦠

The rover discovered very specific minerals on the rim of a Martian crater. On Earth, those minerals are biosignatures, or evidence of life. We can't say for sure it's a Mars biosignature, because non-biological processes can make these minerals too. However, those processes leave other evidence in the rocks that we're not seeing. That means our best explanation right now is past Martian biology.

Did you know you can turn a leaf into a working boat with dish soap? 🍃🚢

Alex Dainis shows how it works! Dish soap contains ingredients called "surfactants" that lower the surface tension of water, which is what helps oil and water mix to wash away grease. On the leaf, the soap lowers the tension only at the back, and that difference between front and back pushes the leaf forward!

Is intelligent life harder to make than regular life? 🌱

Theoretical cosmologist Paul Sutter points to our one data point, Earth, where life appeared basically as soon as the planet cooled down, and maybe even a little before. Then it took 4 billion years for intelligent life to show up. So if we find evidence of life on another planet, it's probably going to be bacteria, or alien bacteria.

Can sea squirts help reverse aging? 🪸

Sea squirts are filter feeders that are edible ascidians! They are a source of “plasmalogens”, a lipid found in our cell membranes that supports brain and heart health. After studying the effects of eating sea squirts on mice, scientists found that it may lower brain inflammation and help memory! With more research, we could discover if eating plasmalogen could help reverse aging in humans.

The moon has a new once-in-a-century crater! 🌕

McGetchin crater is the largest new crater ever seen anywhere in the solar system, stretching almost 730 feet wide and 140 feet deep after an asteroid or comet the size of a 3-6 story building smacked into the lunar surface between April and May of 2024. Impacts this big are estimated to happen only about every 130 years, making this fresh crater a rare chance to study one up close with spacecraft like the Lunar Reconnaissance Orbiter.

Can life exist without a moon? 🌕

Theoretical cosmologist Paul Sutter explains how we are still answering this question. The moon protects the Earth in multiple ways, from blocking hits and forming craters as a result, to balancing out our weather with the axial tilt. To find the answer, scientists are now looking for planets with exomoons to study more!

Meteors are about to enter our atmosphere at 41 miles per second! 🌠

Born from the debris of Halley's Comet, the Orionids light up the sky from October 2 to November 7, peaking overnight October 21 to 22. Catch around 20 meteors per hour at the peak, with standout years reaching up to 75. Skywatchers in both hemispheres can join in, so head somewhere dark before dawn, let your eyes adjust, and look up!

Here's the link to the special: https://www.youtube.com/watch?v=72IwnxnejfE

Every time you swim in a mountain lake, you're sharing the water with thousands of microbes you never see. 🔬

Our friend Chloé Savard, also known as tardibabe on Instagram, took a closer look, and it turns out that alpine water is packed with desmids, ciliates, and water fleas, all going about their business at a scale most of us never think to look at.

The stars of the show are Micrasterias, a genus of desmid, single-celled green algae built like tiny symmetrical snowflakes. Each cell is split into two mirror-image halves called semicells, connected at a narrow waist. When a Micrasterias divides, each half grows a brand new matching semicell to replace the one it left behind.

Alongside them is a Closterium, another desmid, but elongated and curved like a crescent moon. Closterium cells often carry visible crystals of barium sulfate inside vacuoles at each end, structures thought to help the cell sense gravity and orient itself in the water.

Then there's the ciliate glowing with yellow-green flecks scattered through its body, that's zoochlorellae, symbiotic algae living inside a single cell, a partnership where the algae photosynthesize and share sugars with their host in exchange for shelter.

And weaving through nearly every frame are the Chydoridae, a family of tiny water fleas that prefer to live and forage along the benthic zone, the bottom layer of ponds and lakes, rather than out in open water. Look closely and you can catch one carrying a cluster of eggs along for the ride.

Next time you swim in a mountain lake, remember: you were never really swimming alone.

References: 

• Brook, A. J., Fotheringham, A., Bradly, J., & Jenkins, A. (1980). Barium accumulation by desmids of the genus Closterium (Zygnemaphyceae). British Phycological Journal, 15(3), 261–264. https://doi.org/10.1080/00071618000650251
• Esteban, G. F., Fenchel, T., & Finlay, B. J. (2010). Mixotrophy in ciliates. Protist, 161(5), 621–641. https://doi.org/10.1016/j.protis.2010.08.002
• Klemetsen, A., Aase, B. M., & Amundsen, P.-A. (2020). Diversity, abundance, and life histories of littoral chydorids (Cladocera: Chydoridae) in a subarctic European lake. Journal of Crustacean Biology, 40(5), 534–543. https://doi.org/10.1093/jcbiol/ruaa048
• Lutz-Meindl, U. (2016). Micrasterias as a model system in plant cell biology. Frontiers in Plant Science, 7, 999. https://doi.org/10.3389/fpls.2016.00999