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• We are reliant on satellite services for modern life. We use them for communication, banking, navigation and so much more.
• In order to use satellites, we need to know exactly where they are. And that also depends on where Earth and the sun are, too.
• So astronomers use radio waves from distant black holes to help pinpoint our place in the universe. But the radio spectrum is getting crowded.

By Lucia McCallum, University of Tasmania. Edits by EarthSky.

Phones and wifi block our view of our place in the universe

The scientists who precisely measure the position of Earth are in a bit of trouble. We’re talking about geodesy, the science of accurately measuring and understanding the Earth’s geometric shape, orientation in space, and gravity field. These scientists’ measurements are essential for the satellites we use for navigation, communication and Earth observation every day.

But you might be surprised to learn that making geodetic measurements depends on tracking the locations of black holes in distant galaxies.

The problem is, the scientists need to use specific frequency lanes on the radio spectrum highway – where the available radio frequency spectrum is pictured as being divided into “lanes” or smaller bands, similar to lanes on a road – to track those black holes.

And with the rise of wifi, mobile phones and satellite internet, travel on that highway is starting to look like a traffic jam.

Why we need black holes

Satellites and the services they provide have become essential for modern life. From precision navigation in our pockets to measuring climate change, running global supply chains and making power grids and online banking possible, our civilization cannot function without its orbiting companions.

To use satellites, we need to know exactly where they are at any given time. Precise satellite positioning relies on the so-called global geodesy supply chain.

This supply chain starts by establishing a reliable reference frame as a basis for all other measurements. Satellites are constantly moving around Earth, Earth is constantly moving around the sun, and the sun is constantly moving through the galaxy. So this reference frame needs careful calibration via some relatively fixed external objects.

As it turns out, the best anchor points for the system are the black holes at the hearts of distant galaxies. Black holes spew out streams of radiation as they devour stars and gas.

And these black holes are the most distant and stable objects we know. Using a technique called very long baseline interferometry, we can use a network of radio telescopes to lock onto the black hole signals and disentangle Earth’s own rotation and wobble in space from the satellites’ movement.

Different lanes on the radio highway

We use radio telescopes because we want to detect the radio waves coming from the black holes. Radio waves pass cleanly through the atmosphere. And we can receive them during day and night and in all weather conditions.

But we also use radio waves for communication on Earth. This includes things such as wifi and mobile phones. There is close regulation on the use of different radio frequencies, or different lanes on the radio highway. And a few narrow lanes are reserved for radio astronomy.

However, in previous decades the radio highway had relatively little traffic. Scientists commonly strayed from the radio astronomy lanes to receive the black hole signals.

To reach the very high precision needed for modern technology, geodesy today relies on more than just the lanes exclusively reserved for astronomy.

Radio traffic on the rise

In recent years, human-made electromagnetic pollution has vastly increased. When wifi and mobile phone services emerged, scientists reacted by moving to higher frequencies.

However, they are running out of lanes. Six generations of mobile phone services (each occupying a new lane) are crowding the spectrum. Not to mention, a fleet of thousands of satellites directly send internet connections.

Today, the multitude of signals are often too strong for geodetic observatories to see through them to the very weak signals that black holes emit. This puts many satellite services at risk.

How to help find our place in the universe

To keep working into the future – to maintain the services on which we all depend – geodesy needs some more lanes on the radio highway. When international treaties at world radio conferences divide up the spectrum, geodesists need a seat at the table.

Other potential fixes might include radio quiet zones around our essential radio telescopes. Work is also underway with satellite providers to avoid pointing radio emissions directly at radio telescopes.

Any solution has to be global. For our geodetic measurements, we link radio telescopes together from all over the world, allowing us to mimic a telescope the size of Earth. Each nation individually primarily regulates the radio spectrum, making this a huge challenge.

But perhaps the first step is increasing awareness. If we want satellite navigation to work, our supermarkets to be stocked and our online money transfers arriving safely, we need to make sure we have a clear view of those black holes in distant galaxies. And that means clearing up the radio highway.

Lucia McCallum, Senior Scientist in Geodesy, University of Tasmania

We republished this article from The Conversation under a Creative Commons license. Read the original article.

Bottom line: Astronomers help us locate our place in the universe by analyzing the radio waves that come from black holes in the distant universe. But the radio spectrum is getting crowded with our everyday technology.

The first full moon of astronomical summer in the Northern Hemisphere is about to rise. Known as the Buck Moon, it will turn full Thursday, July 10 and will be one of the lowest-hanging full moons of the year.

Although the moon officially reaches its full phase at 4:38 p.m. EDT on June 10, that moment occurs while the moon is still below the horizon for viewers in North America. The best time to see the full Buck Moon will be at moonrise, at dusk, on Thursday evening, when the moon will appear on the eastern horizon as an orange orb. Use a moon calculator to determine the exact time you should look for the moon from your location.

Care and Feeding is Slate’s parenting advice column. Have a question for Care and Feeding? Submit it here.

Dear Care and Feeding,

My husband, “Wade,” and I are Chinese-American. My family has been in the U.S. for generations, while he is the first of his family to be born here. Wade and I have two daughters, ages 2 and 4, whom we adore. The problem is my very traditional in-laws, who are applying pressure to us to try again to have a son. Wade thinks we should just grey rock their attempts to convince us to have another child for the sake of carrying on the family legacy—i.e., let them waste their breath. But I worry about our girls as they get older and are better able to understand the meaning behind their grandparents’ constant harping on this. I fear they’ll think their grandparents love them less than they would if they were boys; I don’t want them to feel inferior because of their gender. What’s a good way of dealing with this without offending my in-laws?

—The Old Beliefs Should Have Stayed in the Old World

Dear Beliefs.

I’ll admit, if I were you, I would be honest with them—I think you can do that without offending them. You and your husband might tell them that you’re very happy with your two children and have no plans for a third. You can do this without getting in the weeds about sons versus daughters (and if they say—and they will say!—“But you don’t have a son! You must have a son!”, my advice would be to repeat what you’ve just said, and to do so as many times as necessary, without engaging with what they see as the “real” issue). You are not going to change them, and only they can decide to leave “the old beliefs” behind: You can’t make them. I would further urge you to speak frankly with them about your concern that if they continue to talk about this in the presence of your daughters, it will hurt them and harm their relationship with them. Tell your in-laws they are not to bring this up when their grandchildren are present—period. Tell them you do not wish for your children, who love and value their grandparents, to come to believe that their grandparents don’t love and value them.

If you and your husband cannot bring yourselves to tell his parents that you have no desire to have another child—even without breaking the news that you couldn’t care less about providing the son they so desperately want you to have—I’m not against your husband’s plan of letting them waste their breath and paying them no nevermind. But even if you go that route, somehow managing to spend the next 10 to 20 years making noncommittal noises or changing the subject every time they bring up the importance of your bringing a boy into the world, that doesn’t mean you shouldn’t speak up about the well-being of your (actual) children. You must still tell them how important it is to you that they not speak of this in your daughters’ presence, and explain why. If they continue to do it anyway, gather your daughters and leave the room. (When you’re next alone with their grandparents, repeat yourself again: This is not acceptable. This may inspire them to tell you, yet again, how crucial it is that you provide them a grandson. If you are determined to keep this charade going, you might say, “Yes, I know, but I must tell you that the repetition of your deep desire for one is not going to make him come along any faster.”)

And more important than any of this: Make sure your daughters know that they are loved and valued, that you and their father treasure them exactly as they are.

Dear Care and Feeding,

My son “Oliver” is 2 ½ years old and going through potty training. We got him some books on the subject and have shown him some videos to help encourage him. The problem is that he has become fixated on the topic. Now everything is about where pee and poop come from, where it’s supposed to go, how it’s something every living creature does, etc. He will initiate these conversations with perfect strangers when we are out; last week, we were at a restaurant when my husband needed to take him to the men’s room. Oliver came running back excitedly to the table and shouted, “I went pee-pee in the potty!” in front of everyone. I realize this is a phase, but I find it terribly embarrassing. Is there any way I can teach him discretion without inhibiting his progress?

—Pooped by All the Poop Talk

Dear Poop Talk,

I’m sorry to have to be the one to tell you this, but you’re going to have to get over this. You have a toddler! He’s excited about pee and poop and fascinated by everything he’s learned about it (and the whole process of food-to-waste-product really is kind of amazing, if you think about it, no? Oh, right, I forgot: You do not want to think about it). When kids are excited and fascinated by a subject, they want to talk about it. To everyone. Just you wait until he gets to the all-dinosaurs-all-the-time phase.

I say let him. It’s your embarrassment you need to get to work on—or, rather, your dread of being embarrassed. What’s so awful about a little embarrassment? (Or, an even better question: What is it exactly that there is to be so embarrassed about?) The appropriate response to his proud announcement was, “Well done! Good job!”, not, “Shhh!” And if he poop-chats up a stranger in the grocery store, and that stranger seems taken aback/distressed instead of amused or even just politely tolerant (recognizing that the person trying earnestly to engage them in a discussion of excrement’s amazing journey isn’t even 3 years old), you can always say, “Ah, well, potty training!” as you sail past. If a toddler uses hate speech (picked up somewhere, just repeating it as children do), that’s one thing: It’s never too soon to teach a child not to be hateful, racist, bigoted, or cruel. But teaching a toddler to be discreet is not only a losing battle, it’s also an effective way of teaching him that his exuberance is something for him to be ashamed of.

Catch Up on Care and Feeding

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Dear Care and Feeding,

I am a married man of many years. In my youth, I had a number of hot rods and have always been a car guy. I had a successful career and now have a net worth of $2 million, and the only debt we have is a small mortgage. There is a particular sports car I would like to purchase that is not expensive. My wife objects—she thinks I would look like an idiot driving this car at my age. All I want to do with it is take it to local car shows and cars-and-coffee meetups—that sort of thing. Is it all right for me to buy it anyway?

—Or Is She Right?

Dear Or Is She,

Does it matter if she’s right or wrong? The question is whether you care if you look like an “idiot,” in your wife’s words. (I’m not weighing in—I have no opinion on this matter. I don’t care enough about cars—or even know enough about cars—to make a judgment about the person driving one.)

If you want this sports car and you can afford it, and it will give you pleasure and do no harm to anyone, it’s time to search your soul: If you fear you might look foolish in your new hot rod, and the thought of that is painful enough to diminish the pleasure you imagine owning it will bring you, then don’t take that chance. If you consider the possibility of being judged harshly—old man in a hot car, ha ha, poor fool—and it horrifies you, as I suppose it horrifies your wife, then you should probably stick to the sedan or SUV you usually drive. But if you don’t care what people think (and why should you?), go ahead and tell your wife that. And tell her she doesn’t have to (ever) sit in the passenger seat, to spare her what I assume is her fear of being looked at as the pathetic old fool’s poor, clueless wife.

—Michelle

More Advice From Slate

I am mom to a 7-month-old. We live in a pretty conservative area, and I work in a male-dominated industry. In fact, all of my co-workers are men who have or had stay-at-home wives. When I was pregnant, several of my co-workers did not expect me to come back to work. Though I told them we planned on using day care, I guess they assumed some maternal instinct would come over me and I’d quit. They said terrible things to me.

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How did life on Earth begin? People have been asking that for ages. The answers remain scattered across rocks, oceans, and ancient landscapes. One clue hides in an essential ingredient for life – phosphorus.

Phosphorus is everywhere in living things. It holds together DNA and RNA. It forms the framework of cell membranes. No life can grow or function without it.

Yet, phosphorus mostly stays trapped in rocks. It hides inside phosphate minerals, which barely dissolve in water. That raises an old and puzzling question: how did early Earth get enough phosphorus to spark life?

Yuya Tsukamoto and Takeshi Kakegawa from Tohoku University took that question seriously. They decided to look where most people wouldn’t – deep under the sea, in rocks that are billions of years old.

Key element for life on Earth

The researchers focused on the Pilbara Craton in Western Australia, which holds some of the oldest known seafloor rocks.

The rocks are an astonishing 3.455 billion years old. The team’s discovery wasn’t subtle. It jumped out from the data.

“We analyzed 3.455-billion-year-old basaltic seafloor rocks in drill core samples recovered from the Pilbara Craton, Western Australia, discovering that P was significantly leached from the hydrothermally altered rocks compared to the least altered rocks,” explained Tsukamoto.

He noted that further mineralogical analyses indicated that phosphate minerals had undergone dissolution in rocks where P was depleted.

Simply put, hot fluids moved through these rocks and pulled phosphorus out. That phosphorus didn’t just disappear. It entered the surrounding seawater, turning parts of the ocean into phosphorus-rich zones.

Tracking the source of phosphorus

The rocks alone didn’t tell the whole story. The team wanted to understand what made this phosphorus release possible. They uncovered two kinds of hydrothermal fluids that shaped this process.

One type was hot, rich in sulfur, and capable of breaking down minerals quickly. The other was more surprising – mildly acidic to alkaline fluids at lower temperatures.

These fluids were common in the Archean era because Earth’s atmosphere back then was filled with carbon dioxide. That unique atmosphere made these fluids react in unexpected ways with the rocks.

The result? Massive amounts of dissolved phosphate in the water. The numbers were shocking. These fluids could carry up to 2 millimolar phosphate – nearly 1,000 times higher than what’s found in modern seawater.

Suddenly, early Earth wasn’t a barren place. Its oceans were filled with phosphorus.

Earth’s oceans held elements for life

This wasn’t just a chemistry experiment. The results changed how scientists think about early Earth. The researchers calculated how much phosphorus these underwater systems could release.

The findings were stunning. The amount of phosphorus released into the oceans by these hydrothermal systems could match, or even exceed, the amount entering modern oceans through rivers and weathering of land rocks.

“Importantly, this study provides direct evidence that submarine hydrothermal activity leached P from seafloor basaltic rocks and quantifies the potential P flux from these hydrothermal systems to the early ocean,” adds Tsukamoto.

Imagine ancient oceans filled with nutrients. These phosphorus-rich waters may have supported some of Earth’s earliest microbial life.

The ancient communities didn’t need a vast, lush planet. It only needed these hidden underwater environments to get started.

Hot springs and hidden worlds on land

The study also pointed to something beyond the oceans – hot springs on land. Hydrothermal systems aren’t just found under the sea. They exist on land too, in places like hot springs.

These environments might have also released phosphorus on early Earth. That means life’s building blocks weren’t limited to deep-sea vents. They could have existed in steaming pools on land.

This opens the door for more discoveries. Scientists now plan to study how phosphate behaves in rocks across different periods of Earth’s history. By tracing phosphorus through time, they hope to unlock new chapters of Earth’s story.

The message is clear: Life’s ingredients may have come from places on Earth we’ve only just begun to explore. Deep beneath the waves, within rocks touched by ancient fluids, the story of life may have quietly begun.

The study is published in the journal Geochimica et Cosmochimica Acta.

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