u/scientificamerican

When the U.S. announced that it has placed weapons in space on September 14, it came as a surprise to absolutely nobody familiar with the subject.

“My initial impression was that it was about time to announce it since it was the worst-kept secret in the world,” says Doug Loverro, who was deputy assistant secretary of defense for space policy during the second Obama administration.

Military use of space isn’t new. Armed forces of the U.S. and other spacefaring countries have relied on satellites for surveillance and navigation for more than half a century—in the 1960s the U.S. and the Soviet Union even blew up nuclear bombs in space. The GPS (Global Positioning System), weather and communications satellites upon which so much of our modern lives on Earth now depend all have militaristic roots. And as this dependency has grown, so, too, have countries’ concerns about defending their assets in space. Gradually, Earth orbit has become not just a place for a god’s-eye overview of our planet but also a hotly contested war-fighting domain.

This admission from the U.S., says Jonathan McDowell, an astrophysicist who tracks rocket launches and in-space activity, is just the next step in that process.

“It’s not out of nowhere,” he says. “The U.S. remains the country that is the most dependent on space assets for its operations, and to that extent, it remains the country that has the most to lose from space conflict.”

Loverro believes the announcement wasn’t much more than an acknowledgment of what people could already see for themselves by looking up. While their actual missions may remain secret, most classified military satellites can be easily tracked and cataloged from the ground. “If we don’t tell them what it is, they’re going to hypothesize what it is—so let’s just be clear,” he says.

Even so, no other nation has ever publicly acknowledged its possession of space weapons. The U.S.’s decision to do so now presumably signals to potential adversaries with thinly veiled space weapons of their own—namely China and Russia—that a new era of accountability for orbital saber-rattling is at hand. But two burning questions remain: What are these space weapons, exactly? And what might they mean for our future down here?

The answers probably aren’t what you’d think.

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As a tool for describing the structure of our own minds, “consciousness” is extremely useful—perhaps even indispensable. But to understand systems that are radically different from us, we may need to forge new concepts.

What happens when machines surpass the most brilliant human minds? Mathematicians are finding out.

More than 180 million years after the supercontinent Gondwana’s breakup, scientists are still learning the true reach of this prehistoric landmass that once stretched across the globe. By analyzing more than 25,000 volcanic rocks, a new study finds that Gondwana likely accounted for around 80 percent of total global land area around 500 million years ago. 

In 2022, researchers detected a very odd photon from an enormous gamma ray burst that should have been destroyed on its way to Earth