Many people turn to companies like 23andMe to learn about ancestry and ethnicity. But the genetic connection is far more complicated than the industry lets on.

By Jack Herrera

It’s always a mess when Latinx folks take DNA tests. Things go alright, until we get to the “ancestry” portion, which some commercial genetic tests label as “ethnicity.”

People who identify as Latinx claim ancestry from all over: indigenous Americans, Spanish colonists, enslaved Africans, Middle Eastern people, miscellaneous Europeans, and even Asians.

This can lead to unexpected DNA results. My grandfather is Mexican, but fair-haired and blue-eyed (we sometimes call people who look like him bolillo, which means “white bread”). When he got his report back from FamilyTreeDNA, he found out he had more North American ancestry than expected. Abuelo made some weird comments — but my friend’s brother’s reaction was much worse. Also Mexican, he came into the living room with his tests results printed out. “I found I’m 3 percent black,” he said. …

The night sky is changing, and we can’t figure out why

By Charlie Wood

History would have us believe that the night sky is permanent and unchanging. After all, navigators have steered their ships using fixed stellar patterns for centuries, and our eyes still trace the same outlines of the same heroes and villains that star gazers have identified for millennia. But what if we just haven’t been watching closely enough? What if our night sky is changing?

A group of astronomers aims to shake that assumption of stability with the Vanishing and Appearing Sources during a Century of Observations (VASCO) Project, by comparing 70-year-old surveys with recent images of the night sky to see what might have gone missing. After years of painstaking work, they recently announced their first results in the Astronomical Journal: at least 100 pinpricks of light that appeared in mid-20th century skies may have gone dark today. The vanished light sources could represent short-lived flashes in the night or, possibly, the disappearance of a lasting heavenly body, if researchers can indeed confirm what they’re seeing. The study authors stress that while their preliminary findings almost certainly represent natural and well-understood events, they hope that future results will be relevant to astronomy and the search for extraterrestrial intelligence (SETI). …

Conference travel, stargazing and supercomputing produce a surprising amount of emissions

By Charlie Wood

Astronomers spend much of their time pondering events that played out eons ago in galaxies many light years away. But when that pondering takes place together with colleagues overseas, or when it needs conceptual backup from detailed simulations on energy-gobbling computers, astronomical research can end up having an outsized effect here on this planet.

Researchers are increasingly coming to recognize that while thought can be carbon neutral, science is anything but. Now a trio of Australian astronomers has estimated how much carbon dioxide their professional activities produce. Between flying to conferences, crunching numbers, lighting their offices, and keeping observatories running, the field emits at least 15,000 tons of carbon dioxide per year in Australia alone — roughly equivalent to the annual emissions of about 2,000 homes, according to a report recently published on the preprint server arXiv. …

The seemingly opposite conditions of autonomous sensory meridian response and misophonia could have quite a lot in common

By Eleanor Cummins

YouTube is a garden of digital delights: Celebrities invite you into their homes, algorithms serve up your favorite music, and strangers whisper you to sleep.

If that last one sounds weird, then you probably ­haven’t experienced autonomous sensory meridian response, or ASMR. For some, things like fluttering fingers and soft voices can trigger “brain tingles,” a pleasurable scalp prickling that cascades soothingly down the body.

Yet other viewers respond negatively to the same cues. Their revulsion is the result of a psychiatric condition called misophonia, in which things like chewing and lip smacking incite a fight-or-flight response. By some estimates, it affects about 20 percent of the population, some so severely they can’t even work or socialize. …

When someone does something cringe-worthy, it might be more about you than them

By Benjamin Powers

Democratic presidential primary candidate Pete Buttigieg’s name has been popping across Twitter the last few weeks. Not because he’s pulled ahead of some challengers in early primary states, but because his supporters have turned his campaign event walk-on song (“High Hopes” by Panic! at the Disco) into a viral dance video.

And not in a good way.

You can view the dance here, where a group of supporters break out the moves in the midst of an organizing meeting. The routine involves four sequences of clapping, arm pumping and waving, and making blender motions with your hands. …

The peculiar bugs could illuminate what signs to look for on Mars and beyond

By Charlie Wood

What might alien life look like, and what traces would it leave behind? If extraterrestrial plant and plankton analogs fill their planet’s atmosphere with oxygen, or an advanced civilization fills its skies with satellites, we might be able to spot such global upheavals from Earth. But if life elsewhere is small and limited in scale, its fingerprints may be subtle and hard to distinguish, even right in our own cosmic backyard.

Any extraterrestrial critters in our solar system, given the lack of obvious greenery and movement out there, are likely to be simple microbes. Perhaps they burrow deep under the Martian soil to hide from damaging ultraviolet rays. Or perhaps some lie dormant in asteroids, waiting to land in a friendlier environment. A team of researchers at the University of Vienna has tried to guess how such microbes could survive on their own, and what marks they might leave behind, by studying one of Earth’s hardiest bugs. …

There’s no evidence to support the use of activated charcoal in beauty or health products

By Kat Eschner

In the past few years, activated charcoal has become a common ingredient in over-the-counter beauty and health products — not to mention it’s also made an appearance in coffee, ice cream, and cookies, among other things, turning them all an elegant black. In particular, the substance has recently become a popular component in skincare, with its presence in this market expected to continue its rise for some time. There’s just one problem: There’s no proof it does any good, and in some cases it might be harmful.

Charcoal itself is simply the carbon residue left over after slow heating high-carbon-content materials like wood, coconut shells or even sugar to remove most of the water they contain. It’s lightweight, highly portable, and burns for a long time at a reliable temperature. Thanks to these properties, humans have used charcoal as fuel for thousands of years. And you know humans: If it’s around them, at some point they’re likely to try to eat it. Nobody knows exactly how or who came up with the idea, but by the time of Hippocrates (approximately 500 CE), some people were using it as toothpaste, thanks to its abrasive properties. …

Something powerful split open the icy moon’s south pole

By Charlie Wood

When the Cassini spacecraft swung by Saturn’s moon Enceladus in 2005, its cameras glimpsed a particularly arresting feature of the alien world: tiger stripes. Where fractures in Europa’s icy shell race across the surface at random angles, Enceladus’s surface hosts five epic fissures running in parallel across its southern pole, each stretching roughly 80 miles in length.

Now a team of physicists suggests they’ve cracked the origin of these stripes: an unruly ocean burst into space and fell as snow that overloaded ice shelves enough to create the handful of rather uniform cracks, according to results published Monday in Nature Astronomy. …