Birds aren't the only animals scientists are hoping to understand. Researchers with Project CETI are using AI to decipher the clicks and calls of sperm whales, while a separate team (with the search for extraterrestrial intelligence, or SETI) conducted what they described as the first "conversation" between humans and a humpback whale. The whale, named Twain, responded to recorded calls played by researchers over a 20 minute period, a "conversation" scientists believe could help us figure out how to communicate with extraterrestrial life someday.

Closer to home, cats have already figured out how to use meows to get their human's attention, whether they're demanding food, affection or simply that we open the door for them (again). Whether this means they understand the human language or not is still up for debate, but it raises an interesting question: If we could understand what animals were saying, which species would you most want to talk to? Vote in our poll and let us know what you'd ask in the comments below!

'> Which animal would you most want to talk to, if you could? Voyager 1 probe, which has been exploring our solar system at increasingly remote depths since 1977, will reach 16.09 billion miles (25.89 billion kilometers) from Earth — a distance so vast, it takes light 24 hours to traverse the space between Voyager and our planet.

While we celebrate this achievement on Earth, Voyager 1 will observe its "light-day" in darkness; mission scientists turned off the probe's camera in 1990, immediately after it snapped its iconic "Pale Blue Dot" and "Solar System Family Portrait" images from beyond the orbit of Neptune. But before that, Voyager 1 had already taken tens of thousands of images of our cosmic neighborhood, and some of them totally transformed our understanding of the outer planets.

One of the most significant pieces of Voyager 1's legacy is its trip to Jupiter. From January to April 1979, the probe observed the solar system's largest planet and several of its giant moons up close, reaching a minimum distance of 174,000 miles (280,000 km) in March 1979, according to NASA. As it approached, Voyager snapped a photo of the gas giant every 96 seconds to create this incredible time-lapse movie of Jupiter's turbulent atmosphere.

Voyager observed discrete bands of Jupiter's atmosphere spinning at various speeds and in different directions, like a cosmic Rubik's Cube being twisted by an invisible hand. Clouds speed by as if on conveyor belts as giant, planet-size storms swirl.

Voyager's time-lapse film captures about 60 full days on Jupiter — the equivalent of about a month on Earth, since each Jupiter day is roughly 10 Earth hours —- providing the most comprehensive and high-resolution look at the planet yet. The observations significantly built on the data captured by NASA's Pioneer 10 and 11 Jupiter probes, which launched half a decade prior, showing the planet's atmosphere to be much more dynamic than astronomers realized.

Just before making its closest approach to the planet, Voyager spotted something remarkable: Jupiter had a thin, faint ring system. Made primarily of dust, the rings appeared only when Voyager saw Jupiter backlit by the sun. No telescope had ever seen this before, but ground-based observatories soon confirmed the rings' existence, and Voyager 2 took even clearer pictures of the rings when it reached Jupiter in July 1979.

We now know that all four outer planets — Jupiter, Saturn, Uranus and Neptune — have rings. Today, scientists suspect Jupiter's dusty rings are replenished partially by volcanic eruptions on the planet's volatile moon Io.

This discovery, too, can be linked to Voyager. While making a close approach to Io, the spacecraft witnessed the first-ever volcanic eruption on a world beyond Earth. This observation showed that moons, not just planets, can be geologically active. In this image, a giant volcano called Loki Patera (the largest volcano on Io, measuring an estimated 125 miles, or 200 km, wide) spews its guts into space.

Taken together, these observations of Jupiter and its moons showed the largest planet and its moons to be a far more dynamic, complicated and chaotic system than anyone had realized. Moreover, the close-up views of these distant worlds made them more than just dots in the sky. It made them fully realized worlds — places to explore, map and eventually visit. Just this week, China's space agency announced its intention to send a lander to Jupiter's moon Callisto in the first-ever landing mission to the Jovian system.

Voyager 1's work continues in interstellar space, which it officially reached in 2012. With its camera off, it studies the radiation environment of space using magnetic field and plasma detectors — the last two of its 10 science instruments still receiving power. Scientists suspect the legendary probe will fully run out of power in the 2030s.

For more stunning space photos, check out our Space Photo of the Week gallery.

'> NASA's Voyager 1 mission forever changed our view of Jupiter

According to Octavian’s account, rather than facing the disgrace of defeat, the queen allowed a venomous asp snake to bite her and quickly succumbed to its poison. Some Roman writers, such as the historian Velleius Paterculus, repeated that story without question.

But others were far less certain of this account, calling it Roman propaganda to cement Octavian's rise to power. And most historians today doubt that a snake was involved at all. So how did Cleopatra die?

Live Science spoke with experts, who told us that the queen's death is still shrouded in mystery.

"We cannot know for sure exactly how Cleopatra died," Prudence Jones, a professor of classics at Montclair State University in New Jersey and author of "Cleopatra: A Sourcebook" (University of Oklahoma Press, 2006), told Live Science in an email.

What historians largely agree on is that Cleopatra VII, the last queen of Egypt's Ptolemaic dynasty, took her own life and that she chose a method that left her body composed and dignified.

Lost evidence

Physical evidence of Cleopatra's death is elusive. Much of Alexandria's royal quarter now lies underwater, and underwater archaeologist Franck Goddio, who has been excavating it, hasn't found the queen's mausoleum, Jones said. Even if Cleopatra's remains surfaced, bones would be unlikely to show evidence of snake venom, she added, noting that forensics is outside her area of expertise.

The best witness may have been Olympus, Cleopatra's personal physician. "Unfortunately, nothing survives of Olympus' account," Jones said.

What does remain is a story told largely by Cleopatra's enemies. The earliest surviving account is a poem by the Roman poet Horace, whose patron was a close friend of Octavian, said Jane Draycott, a historian at the University of Glasgow. His Ode 1.37, written around the time of her death, celebrates Octavian's victory and already pictures the queen handling serpents — yet it ends with grudging admiration for a woman who refused to be paraded as a trophy.

A queen out of options

Following her capture, Cleopatra was held under military guard. By then, she had already tried to end her life twice. Cleopatra had tried to stab herself when Roman soldiers broke into the mausoleum where she had barricaded herself, and she later tried to starve herself, stopping only after Octavian threatened her children.

To Draycott, those attempts leave little doubt that Cleopatra would rather die than live as a captive. "She does not want to be a prisoner; she does not want to be led through the streets of Rome in triumph as a defeated foe," she told Live Science.

In the Greco-Roman world, suicide didn't carry the stigma it later acquired under Christianity, she added. "It was a way of wiping the slate clean, removing any shame, any disgrace from yourself." After the defeat of his remaining forces at Alexandria and hearing a false report of Cleopatra's death, Antony was the first of the two lovers to die by suicide.

According to the Greek biographer Plutarch, who based his account on that of Cleopatra's personal physician, Cleopatra visited Antony's tomb, bathed, ate and sent Octavian a sealed letter asking to be buried beside Antony, signaling that she meant to die. Octavian realized what was happening and sent messengers rushing to her, but they arrived too late. They found her dead in her royal regalia, with her attendants Iras and Charmion dying beside her.

The trouble with the snake

Jones has compiled what ancient historians, biographers, geographers and physicians wrote about Cleopatra's death. Every source mentions a snakebite, but several also suggest other possibilities, including a poisonous ointment, poison hidden in a hollow hairpin, and snake venom poured into a wound the queen made by biting herself. Only one of these writers, the geographer Strabo, was alive when Cleopatra died, and the only people in the room with her died, too.

The Roman historian Cassius Dio wrote that the sole clue was a pair of faint pricks on her arm. That doesn't settle much, however. "A cobra bite can appear as two small puncture wounds, but not all cobra bites appear this way and not all double puncture wounds result from snakebites," Jones said.

Jones traces the snake version of the story to Octavian, who was in Alexandria when Cleopatra died. Plutarch reported that an image of Cleopatra with an asp clinging to her was carried in Octavian's triumphal procession in Rome. "Octavian, however, was Cleopatra's enemy and for that reason we may not want to accept his account uncritically," Jones said.

Draycott suggested another possible source of confusion: Snake-shaped jewelry was fashionable in Alexandria at the time, so Romans viewing an effigy of the queen may have mistaken a snake bracelet for a real snake.

Draycott doesn't think one snake could have killed all three women. Jones is less certain. Snakes don't inject the same amount of venom with every bite, and some "dry bites" deliver none at all, Jones said. "On the other hand, I don't think it is impossible, as the body of a cobra contains enough venom to kill multiple people," she added.

A quiet poison

The general view among historians, Draycott said, is that Cleopatra took some kind of poison — one that worked quickly and didn't cause seizures or vomiting. The absence of these symptoms is telling: An asp is believed to be what is now known as the Egyptian cobra (Naja haje), whose venom causes a slow, agonizing death with respiratory failure.

Cleopatra likely would have had other means, then. Alexandria was the Mediterranean's center of scientific study, and texts from the period, such as Nicander's "Theriaca," catalog venomous animals, Jones noted. Cleopatra's father, Ptolemy XII, even consulted the pharmacologist Zopyrus about antidotes. Plutarch claimed that Cleopatra personally oversaw experiments that observed the effects of deadly poisons on condemned prisoners.

Still, that claim and other poison stories should be read with caution, Draycott said, because they draw on Roman stereotypes about women. In the Roman view, "manly men will battle with swords," while women, seen as "deceitful and weak" at this time, were thought to kill in secret. "They'll sneak it into your food," Draycott said, summing up the stereotype.

Roman writers were equally suspicious. Poisoning allegations dogged the Hellenistic dynasties of ancient Egypt and the neighboring Seleucid kingdom, as well as Rome's own imperial family. Some were probably true, Draycott said, but others may have been foodborne illnesses or other health conditions people didn't understand.

The method may remain a mystery, but for most historians, the motive doesn't change: Cleopatra chose to die on her own terms.

Are you a fan of mummies and hieroglyphs? Find out with our ancient Egypt quiz!

'> How did Cleopatra really die? Artemis II mission looked out their capsule window on April 10, 2026, and saw the bright-blue Earth below them. The crew had traveled more than 250,000 miles (400,000 kilometers) from our planet — farther from Earth than any humans had ever gone — and now, home was just a few hundred miles straight down.

Only one milestone remained: splashdown, a fast and fiery plunge into the Pacific Ocean that would mark the end of humanity's first crewed mission to the moon in more than 50 years.Mission specialist Jeremy Hansen, the lone Canadian Space Agency astronaut on the crew, had every reason to be confident that the team's Orion crew capsule would hold up just fine. But this was Hansen's first time in space, and his first time dropping through the sky like a fireball at 24,600 mph (39,600 kmh).

It wasn't that he was afraid for himself, Hansen explains in "Earthrise: Inside Artemis II, the Groundbreaking Human Mission into Deep Space" (Hanover Square Press, 2026), which he co-wrote with John Larsen). Rather, he knew that his wife Catherine and three children would be among the millions of Earthlings watching the most dangerous moment of his mission from below.

In this excerpt from the book, Hansen describes the thrilling intensity of splashdown and the euphoria of knowing that he and his crewmates were going to make it back safely — and make history.

Immediately after jettisoning the European Service Module, and exactly half an hour before we were due to splashdown, Mission Control initiated the crew module raise burn. This nineteen-second burn was the first and only burn using the small thrusters built into our Orion capsule. It slightly shallowed our entry trajectory to put us right in the sweet spot while also providing some added distance from the service module, as we'd be hitting the atmosphere in near succession. It, too, went flawlessly. I tightened my straps; it was time for the fireworks.

A re-entry into the Earth's atmosphere is absolutely on the short list of the most incredible experiences of my life. We slammed into it at 7:53 p.m., thundering down at over 10 kilometres [6.2 miles] per second. Per second.

The thrusters fired almost constantly to stabilize the capsule: loud thuds, as if Thor himself were hammering on our spacecraft, as the G-forces quickly began to build, aggressively scrubbing off the velocity we had added to our rocket nine days earlier. Within seconds, we saw plasma forming outside our windows, and the heat at the base of our capsule grew so intense that flames soon engulfed us. It started red and transformed into a bright, bluish-green, pulsating light. It was breathtaking, the bright colors igniting our senses.

It was insane to think about what we were doing. We all knew how this worked; we all knew the science. But deep inside, I also recognized that astronauts must have a screw loose to do this. Nobody in their right mind would strap themselves inside a metal canister that itself was sitting inside a giant fireball. But there was no other way down, and I had accepted the realities of this journey long in advance.

Although I was at peace, I felt guilty for the stress I was putting on my family. I had talked to them openly about the mission's risks, and this was the highest-risk moment. I tried to send my love telepathically, telling them it was going great.

As we continued our freefall, it looked like a thousand camera flashes were exploding inside Integrity. I lowered the sun visor on my helmet. There were only centimeters of heatshield and aluminum separating me from the more than 2500°C heat outside. Almost instantly, the heat inside our cramped home also began to rise, an increase that engineers refer to as "thermally benign." All I know is that I couldn't feel it, blissfully wrapped in my thermally controlled garments.

As we continued to fall, the G-forces built up to nearly four times the pressure we feel on Earth. I wasn't too worried, having endured more than five minutes of the same G-force, or more, in the NASA centrifuge trainer. I had half-expected the freefall back to Earth to seem short, but it was a long six minutes before the flames finally ceased and we re-established communications with Mission Control.

I loved every second of it.

It had already been a wild ride, but I also knew another crazy part — parachute deployment and the actual splashdown — lay ahead. My adrenalin kept pumping.

"Integrity, Houston. Comms check, post-blackout," we heard from Mission Control. It was music to our ears. It was exactly 8:00 p.m.

"Houston, Integrity," Reid [Wiseman, mission commander], replied. "We have you loud and clear."

This is when people the world over clapped, hugged, and, in some cases, cried. For the folks at NASA, it was clear that all had gone well during the descent — a small fleet of NASA and Air Force planes had captured it on high-resolution cameras. But, for me, it wasn't over yet. I wouldn't truly feel safe until our three main parachutes successfully deployed. If they didn't, we'd be a chunk of metal slamming into the ocean at incredibly high speed, and the chances of surviving that would be somewhere between minimal and non-existent.

I've watched many of my close friends return from space, and I find the minutes after surviving the re-entry heat until the parachutes deploy to be the hardest part to watch. When I see a capsule plunge through the clouds with no chutes, I always worry they might not appear at all. That's completely terrifying.

I thought of Catherine and the kids, sending them a "don't worry, gang" message in my mind. Catherine later told me that she had a very bad feeling about the heatshield, so when we emerged from blackout, she began crying and didn't even focus on the parachutes.

Three minutes later, at an altitude of 7,100 metres, timed explosions released small chutes that pulled off the cover for two larger chutes, called drogues because they are intended to slow our acceleration to a speed that would allow our main parachutes to open without ripping. They did their job perfectly, but it was wild inside the capsule, jerking us back and forth like a ride at the fair.

One minute later, at only 1,500 metres above the ocean, the drogue chutes cut loose, and, for a few moments, we felt like we were falling backward. Then, in succession, the three main parachutes began deploying, blossoming slowly so they wouldn't tear apart. The rate of our fall slowed as the red-and-white nylon canopies, each 35 metres in diameter, filled with air. The thrusters kept firing, aiming the capsule's base directly toward the point of impact.

"Integrity, we see three good-looking parachutes," we heard from our CAPCOM. Within seconds, our splashdown speed had reduced to 27 kilometres per hour.

That's it, I said to myself. I'm pretty sure we can survive whatever else could be thrown at us now.

Christina [Koch, mission specialist] seemed to agree. We grabbed one another's hands in a moment of celebration.

Excerpted from "Earthrise: Inside Artemis II, The Groundbreaking Human Mission Into Deep Space" by John Larsen with Jeremy Hansen. © 2026 by John Larsen, used with permission by HarperCollins/Hanover Square Press.

Help us improve Live Science Pro: We're always trying to make our content better. Leave us feedback about Pro here.

'> 'Flames soon engulfed us': Artemis II astronaut Jeremy Hansen describes his mission's riskiest moment

We know that a host of creatures ‪—​​ from whales, to snakes, to sloths ‪— pass gas. But do we know which animal is the top tooter? Experts told Live Science the answer is blowing in the wind.

"Getting quantitative measurements for farts per animal is pretty difficult," Nick Caruso, a data scientist and co-author of '"Does It Fart?: The Definitive Field Guide to Animal Flatulence'' (Quercus Publishing, 2017), told Live Science in an email.

What we can do is hypothesize using the data we do have. Expelled gas is made partially of methane, so comparing methane emissions produced by different species may provide a clue. However, this method does have limitations, experts pointed out.

Fart league

Researchers measure the methane animals produce by placing them inside respiration chambers, then inserting a capsule into the stomach that releases a tracer gas while strapping them with a harness that samples their breath. Alternatively, they capture their breath at stations where they feed or are milked.

Research points to livestock, especially cows, as major methane emitters. A recent report puts their total methane emissions at 117 teragrams per year. (One teragram is equal to 1 billion kilograms, or 2.2 billion pounds.) A buildup of cow-generated methane gas even caused a dairy shed in Germany to explode. However, contrary to what many people believe, the "overwhelming majority" of methane emissions from livestock is released through burping, not flatulence, Ermias Kebreab, a professor of animal science at the University of California, Davis, told Live Science in an email.

The reason comes down to where in the gut the gas is made. Herbivores can't break down plant material on their own; they rely on microbes in their guts to ferment it, and that fermentation releases gases such as methane and carbon dioxide, Dr. Marcus Clauss, head of research and co-director of the Clinic for Zoo Animals, Exotic Pets and Wildlife at the University of Zurich, told Live Science in an email. Some of this gas is absorbed into the bloodstream and exhaled. The rest tends to leave by the nearest exit ‪—‬ animals that ferment their food toward the front of the digestive tract mostly burp it out, while those that ferment it toward the back mostly pass it as wind, Clauss explained.

Cows and other ruminants ‪(such as buffalo, sheep, goats and camels)‬ ferment their food in a chamber called the rumen, located near the front of the digestive system, so most of the methane they produce is through belching, Matthew Hayek, an associate professor of environmental studies at New York University, told Live Science in an email.

So if it's not cows, which animal is the top farter based on their methane emissions? The best candidates are hindgut fermenters ‪—‬ herbivores that digest plant matter in the large intestine (the hindgut). Meat eaters, by contrast, typically produce far less methane than herbivores do, Clauss said.

One possible contender are termites, which break down wood and grass in their hindguts. Their global population is estimated to be around 27 quadrillion (that's 15 zeros) individuals, and they collectively emit 10 teragrams of methane per year.

But, per individual, the title might go to horses. According to a 2019 report from the Intergovernmental Panel on Climate Change, horses have the highest methane emissions among hindgut fermenters — around 40 pounds (18 kg) of methane per horse each year.

However, Clauss is skeptical. "The ranking of horse as highest is only because it has been measured," he told Live Science in an email. "But there are so many hindgut fermenters not measured, like rhino ... Who knows?"

If we consider methane emissions per unit of bodyweight, the nutria (Myocastor coypus) ‪—‬ an herbivorous, semiaquatic rodent ‪—‬ would have higher methane emissions than the horse, Clauss said.

Clauss also questioned the accuracy of using methane emissions data as an indicator of flatulence. "There is some methane in flatulence, but most likely the majority of methane produced by an animal is exhaled, i.e. it goes via blood to the lungs," he said.

So until scientists figure out how to measure animal farts, any ranking remains speculative. For now, scientists have developed ways to track intestinal gas in people, including swallowable electronic capsules that measure gases inside the gut and clip-on underwear sensors that detect hydrogen in farts.

Does animal flatulence contribute to climate change?

Methane is a particularly potent greenhouse gas when released into the atmosphere, and the quantities that large herds of cows and other ruminants emit through burping are enough to contribute to climate change. Indeed, scientists are experimenting with ways to reduce methane emissions from cattle — for example, by adding seaweed to their diet.

But animal flatulence is not a major contributor to global methane increases, Hayek said.

Even methane emissions from termite flatulence, while large, do not have an impact, Stefan Arndt, a professor of physiological and ecosystem ecology at the University of Melbourne in Australia, told Live Science in an email. "A large proportion of that methane is then consumed by methanotrophic bacteria in the soil," he said. These bacteria use methane as an energy source, thereby reducing the net methane emissions from termites substantially.

"Their emissions are part of the natural cycle of methane that has always been there for millennia," Arndt added. "The increasing methane concentrations in the atmosphere that are leading to climate change are caused by humans."

'> Which animal farts the most?