No one knows where it came from, but it’s here now. And the chase is on.

Astronomers around the world are monitoring an interstellar comet hurtling through the solar system, known for the moment as C/2019 Q4. It’s the second time in less than two years they’ve seen an object from another star swing through our cosmic neighborhood. The first time around, the discovery kicked off a worldwide sprint to inspect the object before it got away. It was mysterious enough that some astronomers even began to consider whether it was dispatched by an advanced alien civilization.

This second interstellar object was spotted in late August by Gennady Borisov, an amateur astronomer in Crimea. Borisov has a reputation for catching never-before-seen comets with his telescopes, but they’re from around here; like everything else in the solar system—the planets, the moons, a sea of asteroids—they trace an orbit around the sun. And over the last few weeks, it’s become very clear that this comet does not.

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To be a parent is to be compromised. You pledge allegiance to justice for all, you swear that private attachments can rhyme with the public good, but when the choice comes down to your child or an abstraction—even the well-being of children you don’t know—you’ll betray your principles to the fierce unfairness of love. Then life takes revenge on the conceit that your child’s fate lies in your hands at all. The organized pathologies of adults, including yours—sometimes known as politics—find a way to infect the world of children. Only they can save themselves.

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Our son underwent his first school interview soon after turning 2. He’d been using words for about a year. An admissions officer at a private school with brand-new, beautifully and sustainably constructed art and dance studios gave him a piece of paper and crayons. While she questioned my wife and me about our work, our son drew a yellow circle over a green squiggle.

Years ago, when she was practicing her closing arguments at the family dinner table, Martha Kavanaugh often returned to her signature line as a state prosecutor. “Use your common sense,” she’d say. “What rings true? What rings false?”

Those words made a strong impression on her young son, Brett. They also made a strong impression on us, as we embarked on our 10-month investigation of the Supreme Court justice. We conducted hundreds of interviews with principal players in Kavanaugh’s education, career, and confirmation. We read thousands of documents. We reviewed hours of television interviews, along with reams of newspaper, magazine, and digital coverage. We studied maps of Montgomery Country, Maryland, as well as housing-renovation plans and court records. We watched Kavanaugh’s confirmation hearings multiple times.

In 2016, Bernie Sanders described the Working Families Party (WFP), a grassroots progressive organization, as “the closest thing there is” to his “vision of democratic socialism.” The group endorsed him in his primary race against Hillary Clinton, and it’s grown more powerful in the past three years, as it has sought to build a multiracial populist movement nationwide. But this time around, with Sanders taking another shot for the White House, the group is throwing its weight behind someone else: Elizabeth Warren. The group’s surprising decision could be an early indicator of how progressives—including those who backed Sanders in the past—are planning to organize and vote next year.

“The political conditions are different” in this election, Maurice Mitchell, the national director of the WFP, told me earlier this week, after the group announced that 61 percent of its members had voted to back Warren, compared with 36 percent for Sanders. Unlike in 2016, there is more than one progressive candidate in the race to choose from, Mitchell said. Warren “has a track record of finding that nexus between visionary structural change and also the tools to operationalize it.”

It’s a bit embarrassing to finish a book by Malcolm Gladwell—master of the let me take you by the hand prose style, dealer in the simple and unmistakable thesis—and realize you don’t quite know what he’s driving at.

Gladwell’s method is well established and, you would think, fail-safe. It’s one of the reasons his books have sold millions of copies. Among his other talents, he’s one of those “professional communicators” that public-speaking coaches always say we should emulate: First he tells his audience what he’s about to tell them, then he tells them, and then he tells them what he just told them. He should be impossible to misunderstand. I must be an idiot.

Another possibility is that nearly 20 years after The Tipping Point, his best-selling debut, the Gladwell formula is at last exhausted.

The MIT Media Lab has an integrity problem. It’s not just that the lab took donations from Jeffrey Epstein and tried to conceal their source. As that news was breaking, Business Insider reported that the lab’s much-hyped “food computer” didn’t work and that staff had tried to mislead funders into thinking it did. These stories are two sides of the same problem: sugar-daddy science—the distortion of the research process by the pursuit of money from ultra-wealthy donors, no matter how shady.

Historically, research has been funded by grants. Government agencies and foundations announce that they want to fund X, and you, the scientist, write a proposal about why you’ll be awesome at X. If they agree, they give you money to do X.

Annika Reinhold says that she likes playing with animals (she has two cats) and “doing unconventional things that no one has done before.” When the chance came up to teach rats to play hide-and-seek, she was a natural candidate.

One might question the wisdom of training rats to hide, but there’s a good reason to do so. In neuroscience, animal research is traditionally about control and conditioning—training animals, in carefully regulated settings, to do specific tasks using food rewards. But those techniques aren’t very useful for studying the neuroscience of play, which is universal to humans, widespread among animals, and the antithesis of control and conditioning. Playing is about freedom and fun. How do you duplicate those qualities in a lab?

On Sunday, The New York Times published an excerpt of a new book on Supreme Court Justice Brett Kavanaugh by Times reporters Robin Pogrebin and Kate Kelly. The snippet focused on the story of Deborah Ramirez—a classmate of Kavanaugh’s at Yale, who alleged he had exposed himself to her at a college party. While Kavanaugh angrily waved off reports of such behavior during his confirmation hearing, Pogrebin and Kelly wrote that they found both Ramirez’s claim, and Christine Blasey Ford’s allegation of a drunken attempted assault by a high-school-aged Kavanaugh, to be credible.

That was all it took. The president punched out tweet after tweet demanding retribution for the “lies” told about the justice. By the end of Monday, several Democratic presidential candidates had called for Kavanaugh’s impeachment.

In the 15th century, when Europeans first reached the island now named Puerto Rico, it was home to between 30,000 and 70,000 people, sometimes known collectively as Taíno. They came from various ethnic groups descended from several waves of ancestors who came to the island in succession, beginning as early as 3,000 B.C. But a century after the colonizers arrived, official traces of these indigenous peoples were all but impossible to find.

Under a regime of forced relocations, starvation, disease, and slavery, their numbers plummeted. At the same time, colonial officials elided their existence, removing them as a distinct group from the census and recategorizing many—from Christian converts to wives of colonists—as Spanish or “other.”

Liberals in America have a density problem. Across the country, Democrats dominate in cities, racking up excessive margins in urban cores while narrowly losing in suburban districts and sparser states. Because of their uneven distribution of votes, the party consistently loses federal elections despite winning the popular vote.

The most famous case was in 2016, when Hillary Clinton lost the presidential election despite her 2.4-million-vote margin. Clinton carried Manhattan and Brooklyn by approximately 1 million ballots—more than Donald Trump’s margins of victory in the states of Florida, Arizona, Georgia, North Carolina, Michigan, Wisconsin, and Pennsylvania combined.

But 2016 wasn’t a fluke. Neither was 2000, when Al Gore lost the election despite winning 500,000 more votes than George W. Bush. A recent paper from researchers at the University of Texas at Austin concluded that Republicans are expected to win 65 percent of presidential contests in which they narrowly lose the popular vote.