NASA will bid farewell to its history-making Cassini spacecraft, which has been studying Saturn for more than a dozen years and is slated to self-destruct in a “grand finale” on the planet early Friday.

Since 2004, the Cassini spacecraft has been orbiting Saturn and snapping groundbreaking photos of the planet’s rings and moons. The mission has given scientists their closest look at the mysterious planet. “No spacecraft has ever ventured so close to the planet before,” NASA said in a news release.

But because it has been running low on fuel, NASA decided to end its mission by allowing the spacecraft to plunge into Saturn’s upper atmosphere at 70,000 mph. Doing so will help preserve Saturn’s moons for future space exploration, according to NASA.

Scientists believe the spacecraft will lose its signal shortly before 8 a.m. EDT. During its coverage, NASA will stream live feeds from mission control at the Jet Propulsion Laboratory in Pasadena, Calif., where scientists will be receiving Cassini’s final photos. NASA also plans to host a news conference after the grand finale.

Space enthusiasts can watch the Cassini spacecraft’s final descent via the live stream above, starting 7 a.m. EDT on Friday.

We all know the saying: less is more. While that doesn’t normally apply to a Thanksgiving feast, it seems to be a mantra taking hold more and more for American eaters, according to new reports about poultry trends.

Bloomberg reports that smaller turkeys are breaking big this year, noting that inventories of whole hens are down, shoppers are snapping up smaller birds from grocers and some breeders are even developing a distinctive six-pound turkey type (not yet for sale).

Experts are suggesting that smaller family sizes, alternative gastronomic interests and increased desire to avoid food waste could be reasons behind the new trend. (So, yeah, this one can be pinned on millennials too.)

“People are starting to understand it’s not natural to grow turkeys up to 30 pounds,” Ariane Daguin of food company D’Artagnan LLC told Bloomberg.

At Thanksgiving, as many as 45 million turkeys are killed for the annual feast. But turkey has become somewhat less popular over the years, with vegetarian and vegan options proliferating, the American palate evolving and household residents dwindling. And as Daguin noted, the first Thanksgiving was just as likely to feature venison as turkey — making the traditional bird less of a centerpiece to the occasion than perhaps we’ve come to think of it over the years.

Just don’t tell that to the turkey who will get pardoned at the White House this year.

Humanity may be years away from setting foot on Mars, but the Red Planet is turning into something of a monument park for our species all the same. Rovers and landers—some still operating, some having completed their functional life—dot the surface, and orbiters cross the skies overhead. On November 26 at 2:47 PM EST, one more machine joined the growing fleet, and it will be less concerned with what happens on or above Mars and more with what goes on within it.

Launched last May on a 270-million mile arcing trajectory to Mars, the new addition to the Martian family is known as the Mars InSight lander. The name is another in a series of decidedly labored but nonetheless illuminating acronyms for NASA spacecraft—in this case standing for “Interior exploration using Seismic Investigations, Geodesy and Heat Transport.” (The selective capitalizations are, in fairness, a step up from 2004’s Mercury MESSENGER mission, which stood for MErcury Surface Space ENvironment, GEochemistry and Ranging mission. Really.)

Still, the clumsy name belies a nimble ship. InSight weighs just 1,530 lbs., including fuel and the protective aeroshell designed to help it survive the plunge through Mars’s tenuous atmosphere. It measures just 33 to 43 inches tall, depending on how far its three spindly legs compress after landing. The main body of the spacecraft is just 5 ft. wide, without its solar panels deployed. But NASA engineers have packed a lot of science into that comparatively small package.

The spacecraft is equipped with a seismometer that relies on half a dozen different sensors to measure planetary perturbations in a range of frequencies; a movement and wobble sensor that detects anomalies in Mars’s rotation; and, most significantly, a deep thermal probe, which a robotic arm will hammer up to 16 ft. into the surface of the planet, far deeper than any spacecraft has dug before. What’s more, InSight isn’t traveling alone. Trailing behind on its eight-month journey to Mars have been two briefcase-sized CubeSats, deployed by the same rocket that launched InSight itself. Mostly proof-of-concept technology, they are intended to test the practicality of such mini-ships on deep space missions. While they are not essential to the overall mission, if they function as they should, they will help radio back data from InSight as it descends and lands before they sail past Mars and off into space.

As with all Mars missions, the landing was the most harrowing part, with the spacecraft relying on aerobraking, a parachute system and rocket engines to touch down softly on the surface. The landing site itself, at least, will present few challenges. The most interesting parts of Mars, geologically speaking, are its most hazardous ones—areas with craters or mountains or canyons, and other landers have gone there. But InSight’s instruments can gather solid data no matter where they are on the surface, so the spacecraft aimed for Elysium Planitia, a wide plain just north of the equator that NASA has dubbed “the biggest parking lot on Mars.”

It is to NASA’s credit that its map of the landing site includes the location of Martian landers that have come before—Viking 1, Viking 2, Pathfinder, Spirit, Opportunity, Phoenix, Curiosity. At present, Curiosity is still at work; Opportunity may be, though NASA has had no contact with the old rover since last June. InSight is expected to work for at least two years, after which it too will go silent. Its time on Mars will be comparatively fleeting, but the knowledge it sends home about Earth’s closest planetary kin will endure.

Three presidents and countless scandals later, the impeachment of President Bill Clinton on Dec. 19, 1998, may seem like a relic of a different time. But that day 20 years ago remains an extraordinary moment in American history — Clinton became only the second president ever to be impeached when, in the wake of his affair with a 22-year-old White House intern, the House of Representatives formally accused him of perjury and obstruction of justice.

The Senate acquitted Clinton two months later, but for the time being he faced the possibility of becoming the first president to be convicted and removed from office.

Twenty years later, impeachment continues to loom over American politics as the most extreme way a president or other official can be punished for bad behavior in office. However, as the process has played out in public so few times, how it actually works may be less well known.

To better understand impeachment, why it works the way it does and what happened to Clinton, TIME spoke with Michael Gerhardt, a University of North Carolina professor who specializes in constitutional law and has frequently served as an expert witness before Congress on constitutional conflicts.

What is impeachment?

In the United States, impeachment is the process by which federal officials, including the president and federal judges, can be prosecuted and removed from office. While elections are the conventional way of replacing a president or other official, impeachment is intended for situations in which wrongdoing is so severe that more immediate action is necessary.

The Constitution lays out three reasons officials can be impeached — “treason, bribery, or other high crimes and misdemeanors.”

While the first two accusations are relatively straightforward, “high crimes and misdemeanors” is considered to be a broad category — and the founders likely intended for it to be that way. Such crimes would be considered what Alexander Hamilton called “violations of the public trust” in the Federalist Papers, Gerhardt says. In such cases, the president might do something that “benefits [him] in some way but hurts the country in another,” Gerhardt says.

For instance, Clinton misled others about Monica Lewinsky to protect himself from public embarrassment, but in doing so also may have eroded trust in the presidency.

Things that can get an official impeached may not even be crimes, and not all crimes are necessarily impeachable, Gerhardt adds. And while impeachment uses some of the language of a criminal case — such as “conviction” and “trial” — the process is actually a political trial of a political person by their peers. As Gerhardt explains, impeachable offenses are “special kinds of crime only people in office could commit.”

Why did the framers include impeachment in the Constitution?

Impeachment originated in British law, but the framers included impeachment in the Constitution for their own particularly American reasons.

While British law at the time also used a process of impeachment to prosecute individuals for treason or “high crimes and misdemeanors,” in practice, the bar of lords could impeach all the King’s subjects — whether or not they were officials — for any reason. The framers of the American Constitution narrowed impeachment to only include only federal officials, including the president.

Gerhardt says that the framers used impeachment as a way to make certain that everyone, including the president, is subject to the Constitution. It thus functions as part of the system of checks and balances that ensures each branch of the government has the ability to temper the power of the others.

“They didn’t want to go back to a world where the king was immune to impeachment, or to where ordinary people could be impeached,” Gerhardt says.

What are the steps in an impeachment?

On Dec. 19, 1998, President Clinton was impeached by the House of Representatives. However, impeachment is only the first stage in the two-pronged process to remove a president or another federal official from office.

After the House votes to impeach, the Senate must then hold a trial to determine whether an official is “guilty” and should actually be removed from office. To start the impeachment process, an individual member of the House must request that impeachment proceedings begin, or the House itself could pass a resolution to launch the proceedings. The Speaker of the House would then refer the process to the House Judiciary Committee, which must then determine if there is enough grounds for the process to move forward. If the committee finds enough evidence, it would then draft “articles of impeachment” and vote on whether to bring the articles to the House floor.

The case for impeachment would then go before the rest of the House. If a simple majority votes to pass the articles of impeachment, the President or other official is impeached.

After that, a two-thirds majority of the Senate must decide whether an official is guilty or not guilty of the charges in the articles of impeachment. For most officials, the President pro tempore of the Senate would oversee the process — but if the president were the official being tried, the Chief Justice of the Supreme Court would preside. If a two-thirds majority votes to convict, the official would be removed from public office. Afterward, the Senate could also vote to disqualify them from holding a federal office in the future and take away the official’s pension or other benefits. The convicted official could even face criminal or civil charges.

Read more: A Complete Timeline of Key Moments in the Clinton-Lewinsky Scandal

Why don’t impeachments happen more often?

Impeachments require a significant amount of political will, Gerhardt says. An impeachment will take up a lot of a Congress’s time and energy, and congress members who support impeachment have a lot to lose and potentially little to gain by undertaking an impeachment.

In practice, in order to actually remove a President from office, members of his or her own party must decide that there is enough public desire to impeach him or her, as Elaine Kamarck of the Brookings Institute has explained. “In order for an impeachment to move forward, a president’s own party has to get on board with an impeachment vote. For that to happen, it would mean that the president’s supporters in the electorate have lost faith in him,” she wrote.

In Clinton’s case, Senate Democrats ultimately decided not to convict, but it wasn’t always clear that they wouldn’t turn on him, Gerhardt says. “A lot of these people found that there was misconduct,” he says, “but there wasn’t enough to impeach him.”

Why was Clinton impeached?

The House voted to pass articles of impeachment on Dec. 19, 1998, on two charges: perjury and obstruction of justice. Prosecutors alleged that Clinton had perjured himself by testifying to investigators that he had not had “sexual relations” with Monica Lewinsky, and that he had attempted to encourage White House staff to give false testimony by denying the relationship.

Gerhardt said that, while popular support for impeachment waned as the proceedings went on, a significant undercurrent of public anger drove the proceedings forward.

“You don’t get an impeachment without a good deal of hate,” he says. “There were a lot of people who hated Bill Clinton.”

Why wasn’t Clinton convicted and removed from office?

Ultimately, there was uncertainty as to whether or not Clinton’s wrongdoing had been serious enough to justify removing him from office — as well as insufficient public support for doing so.

Bill Clinton’s approval ratings remained high throughout his second term of office, including during the trial. The impeachment seemed to galvanize the country to support him. His peak job-approval rating — 73% — was recorded the very week of the impeachment, according to Gallup. When Clinton and independent counsel Kenneth Starr were named Person of the Year in 1998, TIME columnist Michael Kinsley wrote that the lack of public interest in Clinton’s alleged misconduct was striking:

While many Senators thought that Clinton’s behavior was wrong, many did not agree that it was worthy of a conviction.

“In voting to acquit the President, I do so with grave misgivings for I do not mean in any way to exonerate this man,” Senator Susan Collins of Maine said in announcing her decision.

What happened to Bill Clinton after the impeachment?

Although Clinton was never convicted, he arguably did not get away unscathed from the proceedings.

Clinton’s law licenses with the U.S. Supreme Court and the Arkansas bar were suspended, which prohibited him from practicing law after his time in office. After he was suspended from the Supreme Court Bar in 2001, he chose to resign his license rather than be permanently disbarred. Possibly the biggest consequence of Clinton’s impeachment, however, was the mark it left on his public record.

On Jan. 17, 2001, Gary Langer ABC News characterized how most Americans felt about Bill Clinton at the time: “You can’t trust him, he’s got weak morals and ethics — and he’s done a heck of a good job,” Langer wrote.

Robotics firm Boston Dynamics is showing off its latest creation: A robotic dog that can open doors.

In a video posted by Boston Dynamics, the company’s SpotMini robot is seen struggling to get past a locked door — until another SpotMini shows up with a special arm that opens the door. The second robot then holds the door open for its robotic buddy. It isn’t clear if the robots are acting autonomously or if someone’s controlling their movements behind the scenes.

Boston Dynamics’ videos never fail to impress — or to terrify, depending on your views of robotics and artificial intelligence. The company’s creations may have been the inspiration behind a recent episode of the dystopian sci-fi series Black Mirror in which robotic dogs set out to kill all living things. But robots like the kind Boston Dynamics makes can have real-world benefits, like the ability to find people stranded in the rubble after an earthquake.

Japanese conglomerate SoftBank purchased Boston Dynamics from Google parent company Alphabet in 2017 for an undisclosed sum.

Americans eagerly anticipating the first total solar eclipse visible in the contiguous U.S. since 1979 — and the first to cross the country from coast to coast in 99 years — may know well know that what they’re watching is the moon simply passing in front of the sun. But even so, as long as eclipses have occurred, humans have interpreted them as a sign of something.

As TIME editor-at-large Jeffrey Kluger explains in the above video, the Lydians and the Medes ended a war in 585 B.C. because they took a solar eclipse eclipse as a sign of heavenly disapproval. The Roman author Pliny the elder drew a line from the eclipse of 59 A.D. to towns being struck by lightning. Eclipses were even thought to have influenced tragic events that happened years later, as was the case with the death of King Henry I in 1135, two years after an eclipse.

Some may also have considered a 1652 total solar eclipse to be partly responsible for the Great Plague of London and the Great Fire of London about a decade later, says John Dvorak, a planetary geophysicist and author of Mask of the Sun: The Science, History, and Forgotten Lore of Eclipses. Harvard’s Commencement Day in 1684 was moved up a day because a total solar eclipse would be visible from Martha’s Vineyard, though university president John Rogers said that the decision was a matter of convenience rather than superstition. The 52-year-old administrator would, eerily, end up dying on the day of the eclipse from what was described back then as a “visitation of sickness,” and it was later announced that he passed as the sun was “beginning to emerge out of a Central Ecclipps.”

Yet, even during what were perceived to be highly superstitious times, ancient astronomers could already believe there must be something more to the phenomenon.

Around 500 B.C., people were staring to talk about eclipses having natural causes rather than supernatural ones, says Tyler Nordgren, an astronomer and professor of physics at the University of Redlands. Ancient Greek historian Herodotus claimed that the philosopher Thales was able to predict when a total solar eclipse would occur (though how he would have done that is not known). To top it all off, “Aristotle was looking at the shadow that the Earth cast on the Moon during a lunar eclipse, noticing that shadow was always circular and saying that the Earth must be a sphere,” Nordgren says.

One of the scholars who epitomizes the shift from superstition to science was Edmund Halley, now known for Halley’s Comet. In 1715, he published a broadside arguing that people shouldn’t be afraid of an eclipse, after a prominent mathematician had published an apocalyptic-sounding pamphlet claiming an eclipse that year “foreshews the Destruction of the Fruits of the Earth, the Scarcity of Corn and Fruit, and a Danger of a Raging Pestilence.”

In response, Halley used Isaac Newton’s theory of gravity to produce one of the first maps of the path of an eclipse and noted that the natural phenomenon was not “portending evil to our Sovereign King George.” He also described the way the eclipse would work in a manner that 18th-century readers could understand — and that still works today.

“An Eclipse of the Sun,” he wrote, “proceeds only from natural Causes; and is nothing else but the direct [i]nterposition of the Body of the Moon between our Sight and the Sun.”

Barbie has a brand-new job. In the latest iteration of the beloved toy’s “Career of the Year” line, Barbie is has taken up a career as a robotics engineer.

The iconic doll comes with all the tools of her new trade, designed with the help of real-life robotics engineer, Cynthia Breazeal, an associate professor of media arts and sciences at MIT and founder of the social robot company Jibo, Inc. Robotics Engineer Barbie comes with a doll-sized laptop computer, a tiny robot with moveable arms, and accessorizes her casual look with safety goggles. It’s also worth noting that the doll has swapped her high heels for sensible flats to make it easier to work in a laboratory all day.

Furing her nearly 60 years in the workforce, Barbie has racked up a very diverse resume. Robotics engineer is a new career choice for her, though. It’s part of a growing list of jobs Barbie has undertaken in science, technology, engineering, and math, including as a computer engineer, astronaut, and video game developer.

It’s all part of Barbie’s ongoing evolution from plastic fashionista to ambitious, science-loving role model, becoming a toy for little girls dream of careers in STEM or perhaps being a robotics engineer when they grow up. Mattel isn’t just letting girls play with dolls and dreaming of careers, though. They teamed up with Tynker, an online platform that provides coding classes to children, to teach aspiring robotics engineers some of the skills necessary to make their dreams a reality. They are offering seven free “Barbie-inspired” coding lessons that will focus on logic, problem-solving, and other skills that a potential robotics engineer will need.

The brainy Barbie, who comes in four skin tones, is available online for $13.99.

Many crises faced by President Harry Truman when he came into office in the waning days of World War II. One of them would plague him for years: What to do with the refugees? By some counts, up to 60 million Europeans had been driven from their homes during the course of the war.

At the time, the U.S. was well-established as a destination for immigrant — despite turning away some migrants during the war — but didn’t have a specific law to deal with refugees per se. In late 1945, Truman signed a directive that allowed faster admission and resident-status changes for some refugees. But a wider-sweeping action would be needed, especially as the quota-based system that governed American immigration applied strict limits to the national origins that had the most need of help. Truman subsequently asked Congress to come up with a law that would address the crisis.

This conversation was taking place in the years before the nascent United Nations — which marks June 20 as World Refugee Day — issued the 1951 Refugee Convention, which set out how the international community ought to address people who had been driven from their homes. But, though the world hadn’t yet agreed on those terms, the conversation about refugees was at a fever pitch; even years after the war’s end, millions remained unsettled.

By mid-1947, when the refugee bill he’d requested was not forthcoming, Truman sent Congress a special message explaining why he considered the move necessary.

Here’s how he explained in that message, the full text of which can be found at the American Presidency Project website, why he believed the United States needed such a law:

In 1948, the Displaced Persons Act — which the U.S. Citizenship and Immigration Services office calls the first U.S. law specifically dealing with “refugees” as such — was passed. Truman, in a signing statement, acknowledged his unhappiness with a law that he saw as a halfhearted measure that was overly restrictive and biased.

“I know what a bitter disappointment this bill is — to the many displaced victims of persecution who looked to the United States for hope; to the millions of our citizens who wanted to help them in the finest American spirit; to the many Members of the Congress who fought hard but unsuccessfully for a decent displaced persons bill,” he said. “I hope that this bitter disappointment will not turn to despair.”

Apple last week unveiled the latest additions to its iPhone lineup: The iPhone XS, iPhone XS Max, and iPhone XR. While they boast improvements like an upgraded processor and better battery life, they certainly aren’t cheap — the iPhone XR starts at $749, while the high-end iPhone XS Max goes all the way up to $1,449.

If you’re finding those prices tough to swallow, there’s another potential solution. Apple on Monday released iOS 12, the newest version of the mobile operating system that powers iPhones and iPads. The free upgrade is reportedly giving older iPhones a performance boost. That means it could help you get more mileage out of your existing device before you upgrade. And Apple tested iOS 12 in a public beta period that (hopefully) helped it iron out any bugs before this week’s formal release.

Here’s how you can upgrade your iPhone or iPad to iOS 12, and what you’ll get out of it.

Before You Update to iOS 12

Before you embark on this upgrade journey, you’ll need to do a few things to ensure everything goes smoothly. For one, you’ll need your iPhone or iPad to be charged to over 50%, though leaving it plugged in while it updates is also an option. You should also have your Apple ID username and password on hand just in case you have to verify your identity before you upgrade.

Backing up your device is also important, just in case something goes wrong during the iOS 12 upgrade process. It will also make it easier for you to switch to a newer device should you decide to get a new iPhone. By setting up a new device from a recent backup, you’ll be able to transfer everything from your apps and notifications settings to your preferences and other changes from your old iOS device to your new one.

Backing up is simple enough, as you can do it right from your iPhone or iPad’s Settings app. From there, tap your name, select iCloud, and enable iCloud Backup (or just hit Back Up Now). You can also connect your iPhone to your computer via iTunes and perform a manual backup to your computer instead of iCloud. If you don’t have enough iCloud storage for a full backup, backing up to your computer is the better choice.

Downloading the iOS 12 Update

You can download the iOS 12 update on your iPhone or iPad over Wi-Fi if it’s plugged into a charger.

In the Settings app, select General, then Software Update. If you’re lacking any extra storage needed to download the update to your device, you can temporarily delete (and automatically reinstall) apps to make room until the installation is complete. You can always schedule the install to occur when you’re not using your phone — perhaps overnight so it’s ready to go when you’re up in the morning.

If you’d rather not go that route, you can always connect your iOS device to your computer and update it through iTunes. Just select your iOS device in iTunes, select the Summary tab, and then click “Check for Update.”

Downloading iOS 12 will bring several new features to your iPhone or iPad, including…

Screen Time Can (Somewhat) Help You Manage Your Bad Phone Habits

Screen Time might be one of the most interesting additions in iOS 12. You probably spend a bit longer than you should staring at your phone, receiving messages and replying in kind with humorous quips and GIFs. Screen Time aims to eliminate those distractions by limiting your time spent in certain apps, and making your phone less attractive to use when it’s time for bed. You’ll see a chart displaying how you spent your time on your iPhone, and which apps are taking up your time. You can also set a restriction passcode to prevent you from bypassing the self-imposed limit.

Unfortunately, Screen Time only works if you allow it to. Since you’re the one with the power to enable (or disable) the feature, making sure it does its job depends more on your willpower than on the feature itself.

Augmented Reality Gives Your iPhone New Utility

Apps taking advantage of the iPhone’s augmented reality feature will let you perform tasks like preview furniture in your home (by pointing your camera at its prospective location) or play tabletop games with no actual game board. But Apple’s own augmented reality app is probably the most useful. iOS 12 includes a Measure app, available on the iPhone 6s and newer devices, which lets you measure real-world objects like boxes, walls, and even the cat if it sits still long enough.

Memoji Makes Messaging More Expressive

Apple’s Animoji use the iPhone’s front-facing Face ID system (available on the iPhone X, XS, XS Max, and XR) to animate characters like robots, aliens, and cats using your own face. Memoji in iOS 12 allow you to make characters that look just like you, as long as you think you resemble a Pixar-esque floating head. You can use those Memoji faces in different apps like Messages and FaceTime, where you can use your Memoji in real-time while you deal with a bad hair day.

Managing Notifications Makes More Sense

Thanks to iOS 12, you can finally make sense of the morass of notifications currently clogging up your iPhone’s lock screen. Group notification management is now available, letting you clear multiple notifications all at once without having to dismiss each one by hitting the small X icon. It also makes managing multiple notifications from apps like Messages a lot easier. Instant Tuning lets you set preferences on notifications as soon as you receive them, which makes silencing or disabling unwanted notifications pretty simple.

Better Password and Security Features

Using SMS to enable two-factor authentication on your apps and services? Now you’ll be able to autofill those verification codes so you won’t have to switch between apps every time. Safari can now create and store randomly generated passwords, reducing the risk of your account getting hacked by someone guessing “password123.” Password manager users can rest easy, too. You’ll be able to use apps like 1Password, Dashlane, and other password managers to automatically fill out login prompts, meaning the days of copy and pasting secure passwords is nearly over.

Bonus: Even Old iPhones Can Get iOS 12

If you’ve still got an old iPhone kept alive through screen replacements, battery changes, and a paranoia that requires it stay in a protective case for eternity, you’re in luck. Apple’s iOS 12 brings a bunch of new features to your device, but it’s also designed to support older devices without bringing them to a slow crawl. Apps launch faster, typing is more responsive, and animations won’t be as choppy even though you’re using an older device. The performance improvements make sense, considering Apple’s work to reduce electronics waste.