Curiosity Daily

Could Science Stop Aging? And the Milky Way’s “Broken Arm”

Episode Summary

Learn about how research into senescent cells and senolytic drugs could change aging. Plus: the Milky Way’s broken arm. Additional resources from Andrew Steele: Pick up "Ageless: The New Science of Getting Older Without Getting Old" at your local bookstore: https://www.indiebound.org/book/9780385544924  Website: https://andrewsteele.co.uk/  Follow @statto on Twitter https://twitter.com/statto  YouTube: https://www.youtube.com/DrAndrewSteele  The Milky Way has a 3,000-light-year-long "break" in its arm, and we don’t know why by Briana Brownell  Specktor, B. (2021, August 19). Milky Way has a 3,000-light-year-long splinter in its arm, and astronomers don’t know why. Livescience.com; Live Science. https://www.livescience.com/milky-way-sagittarius-arm-break  Astronomers Find a “Break” in One of the Milky Way’s Spiral Arms. (2018). NASA. https://www.nasa.gov/feature/jpl/astronomers-find-a-break-in-one-of-the-milky-way-s-spiral-arms  The Milky Way Galaxy | NASA Solar System Exploration. (2017). NASA Solar System Exploration. https://solarsystem.nasa.gov/resources/285/the-milky-way-galaxy/  ‌Kuhn, M. A., Benjamin, R. A., Zucker, C., Krone-Martins, A., de Souza, R. S., Castro-Ginard, A., Ishida, E. E. O., Povich, M. S., & Hillenbrand, L. A. (2021). A high pitch angle structure in the Sagittarius Arm. Astronomy & Astrophysics, 651, L10. https://doi.org/10.1051/0004-6361/202141198  Follow Curiosity Daily on your favorite podcast app to learn something new every day withCody Gough andAshley Hamer. Still curious? Get exclusive science shows, nature documentaries, and more real-life entertainment on discovery+! Go to https://discoveryplus.com/curiosity to start your 7-day free trial. discovery+ is currently only available for US subscribers.

Episode Notes

Learn about how research into senescent cells and senolytic drugs could change aging. Plus: the Milky Way’s broken arm.

Additional resources from Andrew Steele:

The Milky Way has a 3,000-light-year-long "break" in its arm, and we don’t know why by Briana Brownell

Follow Curiosity Daily on your favorite podcast app to learn something new every day with Cody Gough and Ashley Hamer. Still curious? Get exclusive science shows, nature documentaries, and more real-life entertainment on discovery+! Go to https://discoveryplus.com/curiosity to start your 7-day free trial. discovery+ is currently only available for US subscribers.

 

Find episode transcript here: https://curiosity-daily-4e53644e.simplecast.com/episodes/could-science-stop-aging-and-the-milky-ways-broken-arm

Episode Transcription

CODY: Hi! You’re about to get smarter in just a few minutes with Curiosity Daily from curiosity-dot-com. I’m Cody Gough.

ASHLEY: And I’m Ashley Hamer. Today, you’ll learn about the cutting-edge research that could change the way humans age, with help from author Andrew Steele. You’ll also learn about a 3,000-light-year-long "break" in one of the arms of the Milky Way.

CODY: Let’s satisfy some curiosity.

Andrew Steele - How senescent cells lead to aging (Cody)

Humans have always sought a fountain of youth — something that could keep them young into old age, and even let them live forever. But it's only been recently that science has been able to tackle the problem of aging head on — and as you'll hear from today's guest, the advancements that have been made are really exciting. Andrew Steele is a computational biologist and science writer and author of the book "Ageless: The New Science of Getting Older Without Getting Old." And to start our conversation, we wanted to clarify: by treating aging, he doesn't actually mean making humans live forever — right?

[CLIP 4:25]

That's....REALLY exciting. So when, exactly, are we going to have these new drugs on the market?

[CLIP 1:41]

Did you hear him say brushing your teeth? Yeah, we were surprised by that too. He'll be back tomorrow to explain how dental health can help to slow the aging process. Again, that was Andrew Steele, a computational biologist and science writer, and author of "Ageless: The New Science of Getting Older Without Getting Old." You can find a link to pick it up in the show notes — and be sure to come back tomorrow for more.

The Milky Way has a 3,000-light-year-long "break" in its arm, and we don’t know why by Briana Brownell (Ashley)

Q: How can you tell that a galaxy has a broken arm?

A: With an X-ray telescope! ...I mean, this particular study used an infrared telescope, but the joke wouldn’t really work that way. But yes, astronomers have recently found a “break” in our home galaxy’s arm — and they’re not sure what caused it.

You see, our Milky Way galaxy is a barred spiral galaxy. Most of its stars, gas clouds, and dust are in five thick spiral arms. These arms rotate in a flat disc around a central zone of stars with elongated, bar-shaped orbits, which is where the “bar” in barred spiral galaxy comes from.

And recently, a group of international researchers have discovered that there is a strangely angled splinter of stars in one of our galaxy’s spiral arms. In other words: a broken arm.

Our sun is in the Orion spur, a minor arm between the larger Perseus arm and Sagittarius arm. It's our neighbor, the Sagittarius arm, that has this strange splinter. While the overall arm curves at an angle of about 12 degrees, the splinter sticks out of it at an angle of 56 degrees — not quite perpendicular, but getting there.

Even though the break is a relatively small piece of the Milky Way, it’s pretty big in absolute terms: it’s about 3,000 light years across. And this splinter is the first one scientists have found in our home galaxy.

But how did astronomers find this break? I mean, we can’t exactly take a picture of the Milky Way — our furthest spacecraft have just barely left the solar system. One clever technique scientists have used to chart the galaxy are maps of Young Stellar Objects, or YSOs. Those are protostars in the final stages of star formation. Because we can detect their infrared light, several major stellar mapping projects have pinpointed hundreds of thousands of them.

The locations of YSOs closely follow the overall structure of the spiral arms, so it was by looking for the patterns of YSOs that scientists found the splinter.

There are several theories for what caused the break, from expanding superbubbles to gravitational instabilities. But scientists aren’t quite sure whether it was an isolated event or it has something to do with the structure of the arm itself.

We’ve seen splinters like this in other, distant galaxies, so they don’t seem to be rare. But this is the first one we’ve observed up close, and that will help scientists to develop and hopefully test theories for what caused this strange break.

My theory? It got in a fight. You know what you say to start a fight in space? Comet me, bro.

RECAP

Let’s do a quick recap of what we learned today

  1. CODY: According to Andrew Steele, the most important part of aging research isn’t helping people live forever; it’s reducing suffering and improving people’s quality of life as we grow old. One way researchers are doing that is by taking a hard look at “senescent” — basically, “old” — cells. Senescent cells are aged cells that accumulate in your body and release molecules to get your immune system to “gobble them up.” The problem is that as you get older, we produce more senescent cells and our immune system isn’t as good at clearing them out. And there’s evidence that as these cells build up, they accelerate the aging process. 
  2. ASHLEY: Right, and that’s why senolytic drugs are so important to anti-aging research: they selectively kill senescent cells. And in experiments in older mice, senolytic drugs have essentially made mice “biologically younger,” helping them do everything from run faster to look more youthful. Dozens of companies are working on senolytic drugs, with some in human trials right now. Which is why Andrew Steele says he thinks we’re on the cusp of, quote, “the greatest revolution in medicine since the discovery of antibiotics.” 
  3. CODY: The Milky Way has a broken arm. The Sagittarius arm, to be precise, which has a 3,000 light-year “break” that juts out at a 56-degree angle. Scientists don’t know what caused it, but they do know it’s not that rare  — lots of other galaxies have breaks like this, too. 
    1. Fun fact: this break is home to a lot of the nebulas you may have seen in space images. If you’ve ever seen the “Pillars of Creation” image, you know the Eagle Nebula. It’s there, as is the Omega or Horseshoe Nebula, the Trifid Nebula, and the Lagoon Nebula.

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ASHLEY: The writer for today’s Milky Way story was Briana Brownell.

CODY: Our managing editor is Ashley Hamer, who was also an audio editor on today’s episode.

ASHLEY: Our producer and lead audio editor is Cody Gough.

CODY: [AD LIB SOMETHING FUNNY] Join us again tomorrow to learn something new in just a few minutes.

ASHLEY: And until then, stay curious!