Saturn’s Moon Count Goes Up, Overtaking The Number Of Jupiter’s Moons

7:08 minutes

a diagram showing saturn's new moons' orbits
Credit: Carnegie Institution For Science (Diagram); Space Science Institute/jpl-caltech/nasa (Saturn); Paolo Sartorio/shutterstock (Background)

Scientists discovered 20 new moons orbiting Saturn, putting the ringed planet up to 82 moons. Each of the new moons is about three miles in diameter. This discovery means Saturn has edged out Jupiter as the planet with the most moons in the solar system. 

Maggie Koerth Baker, senior science reporter for FiveThiryEight, joins Ira to talk about why the planet is such a moon magnet and other science stories, including a study in PLOS that investigated the link between diet and depression. 

Further Reading

Segment Guests

Maggie Koerth

Maggie Koerth is a science journalist based in Minneapolis, Minnesota.

Segment Transcript

IRA FLATOW: This is Science Friday. I’m Ira Flatow. Should we trust science? A new book argues we should, but not for the reasons that you might think. Well, and talk about it.

But first, this score is out and it was a close one, 79-82. What’s that? Well, that tally is the number of moons Jupiter has compared to Saturn. And Saturn is now officially the most moon nefarious planet in the solar system. Astronomers spotted 20 new moons around the ringed planet. My next guest is here to tell us why Saturn is such a moon magnet. Maggie Koerth-Baker is Senior Science Reporter for FiveThirtyEight, usually out there in Minneapolis, St. Paul, but she’s right here in New York with us.


IRA FLATOW: Nice to see what you look like.

MAGGIE KOERTH-BAKER: Nice to see you.


IRA FLATOW: All right, there’s a lot of new moons. How do they define them? Why are there so many?

MAGGIE KOERTH-BAKER: Well, for those keeping track at home, this is 81 more than the Earth has. And I think one of the most interesting questions out of this is, why does Saturn have so many? And why do we have so few?

And that was a really cool article that Charlie Wood did over at Popular Science, sort of focused on this. And it turns out that what the researchers are finding is that these moons that Saturn has, they didn’t start out as part of Saturn.

Like our moon is this result of a giant collision that sort of blew off part of the early Earth billions of years ago. Saturn is just sort of sucking in asteroids as they go by because its gravitational pull is so big. And then once they’re there, they’re running into each other, they’re running into other space objects, and so you get these little bitty trails of almost like dust.

IRA FLATOW: Some of them are bigger, though, right?

MAGGIE KOERTH-BAKER: Some of them are big and some are as small as a kilometer across.

IRA FLATOW: Wow. Wow. And some of them embedded in the rings of Saturn?

MAGGIE KOERTH-BAKER: Some are in the rings, some are outside the rings. It’s just kind of– it seems to be sort of random about where they go.

IRA FLATOW: Could they get more moons, do you think? They can get more there?

MAGGIE KOERTH-BAKER: They could. That’s one of the interesting findings in this paper, is that the process of acquiring moons is actually easier than we thought it was. And so Saturn could get new ones.

IRA FLATOW: Wow. Your next story looks at the national rate of sexually transmitted diseases according to the CDC, which tracks this stuff. The diseases are at an all time high.

MAGGIE KOERTH-BAKER: Yeah. So more than $2.4 million Americans were diagnosed with syphilis, gonorrhea, and chlamydia last year. And that includes a 40% single year increase in what’s called congenital syphilis. So that’s passed from mother to baby during pregnancy. And that’s a big deal because it can kill newborns, it can cause miscarriages, survivors live with life-long health problems.

And even though there is this growing antibiotic resistance issue with STDs, the CDC is kind of saying the biggest part of this is that people just aren’t getting diagnosed and treated. And so they’ve drawn kind of a direct connection between these rising rates of STDs and the falling funding for STD clinics around the country. So many have been closing, some many have been cutting hours. Less places to get diagnosed, less places to get treated.

IRA FLATOW: And your report says there’s an alarming number of newborn deaths linked to this.

MAGGIE KOERTH-BAKER: Yeah, yeah, it’s definitely connected to that. And women and children are kind of one of the really vulnerable populations associated with this. That the big increases have been in women, kind of across the board on this.

IRA FLATOW: I’m not sure if this study mentions or talks about this, but parenthetically we’ve been hearing for years about the growing number of STDs in nursing homes.

MAGGIE KOERTH-BAKER: Yeah, yeah. There’s definitely some studies I’ve seen that have been focused on specific life insurance– or not life insurance, health insurance companies. And they’ve sort of found that there are these sharp increases in older adults over 60. And that a big chunk of that kind of has to do with people who grew up before the safer sex era. And then you go down to the Sun Belt, and you’re having your retirement parties.

IRA FLATOW: That age of Aquarius.

MAGGIE KOERTH-BAKER: That age of Aquarius, it’s still alive.


Get tested, use condoms.

IRA FLATOW: Exactly. Just because you’re older doesn’t mean you’re not going to get it. That’s one of the reasons, one of the lessons.


IRA FLATOW: Now, also, there’s a new study out that looks at the link between diet and depression. Tell us about that.

MAGGIE KOERTH-BAKER: Yeah. So there’s this long history of connecting healthy eating, things less sugar, less processed foods, more fruits and vegetables, with lower rates of depression. What there’s not been is really good evidence showing that to be causal. So we know that people who eat healthy tend to be happier, but we don’t know if they’re happier because they eat healthy.

And this new study is supposed to be kind of a big deal because it’s sort of finding some of those links. These researchers took 76 young adults, who had these junk food heavy diets. They gave half of them a series of healthy eating interventions, so social support, money for groceries, some pantry staples. And the people who ate better, reduced the depression symptoms. But there’s a catch, because there are always is.

IRA FLATOW: There’s always a catch.

MAGGIE KOERTH-BAKER: And the problem is that the researchers didn’t have an active control group. So you had the people that got the treatment, you had the people that nothing happened to during the entire time. And it turns out that the treatment, the attention from researchers, the being given money, that itself can reduce depression symptoms.

So we don’t know whether it was the placebo of someone paying attention to you, or whether it was the diet changing.

IRA FLATOW: If you give somebody some free cash–

MAGGIE KOERTH-BAKER: It turns out that actually sort of makes your life a little better and then you’re not sad.

IRA FLATOW: Not well controlled, that study.

MAGGIE KOERTH-BAKER: Not well controlled.

IRA FLATOW: And finally, you have a story about that paralyzed man that was able to walk using that exoskeleton.

MAGGIE KOERTH-BAKER: Yeah. So this guy, this French optician, who fell 50-feet in a nightclub in 2015 and became paralyzed from the neck down. And then this year became the first paralyzed person to walk using wireless implants in his head to control a bionic exoskeleton, which is amazing. And there’s been a lot of different techniques to try to restore movement to paralyzed people.

But what makes this thing different, there’s a couple of things happening here. First, the implants were significantly less invasive than anybody’s used in the past. They weren’t in the brain itself, they were kind of between the skull and the brain, which makes them easier to access if something goes wrong, easier to fix. And also it’s wireless.


MAGGIE KOERTH-BAKER: Yeah. So what’s going on, basically, is that these implants are sort of picking up signals. This guy spent a year training this algorithm to understand what the signals from his brain meant. And then the algorithm can translate it into movement.

IRA FLATOW: That’s great. That’s really helpful stuff.


IRA FLATOW: Thank you. Maggie Koerth-Baker, Senior Science Reporter for FiveThirtyEight.

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