For a while now, astronomers have suspected that Betelgeuse has a companion. And they might have found it. If it really exists, though, it won’t be around for long. Betelgeuse is a supergiant. It’s about 15 times as massive as the Sun, hundreds of times wider than the Sun, and tens of thousands of times brighter. There’s a wobble in the star’s light that lasts about six years – possibly caused by the gravity of a smaller companion star. A team looked for the companion in 2020 and 2024. The team stacked thousands of short-exposure images together, producing a sharp view of the system. The researchers didn’t see anything in 2020 – but they hadn’t expected to. The two stars were predicted to be too close together to tell them apart. But the team did see the companion in 2024, when the stars were farther apart. If the star really exists, it would be a little bigger and heavier than the Sun. But it’s so close to Betelgeuse that it’s enveloped in the supergiant’s outer atmosphere. That’s pulling the star closer in. Eventually, it should get so close that the gravity of Betelgeuse will rip it apart. And even if that doesn’t happen, before long Betelgeuse will explode as a supernova – bad news for both stars. Betelgeuse is the bright orange shoulder of Orion the hunter. It’s a third of the way up in the east-southeast at nightfall, to the left of Orion’s Belt. More about Orion tomorrow. Script by Damond Benningfield

A research paper published a couple of years ago featured an ominous title: “The Death of Vulcan.” A team of astronomers killed off a possible planet around the star 40 Eridani. In the lore of Star Trek, the star is the home of the planet Vulcan. 40 Eridani is actually a triple star. The main star is the one that’s supposed to host Vulcan. It’s a little smaller and lighter than the Sun, and only about 40 percent as bright. It’s probably older than the Sun, so there’s been plenty of time for life to develop on any planets that orbit the star. And in 2018, astronomers reported the possible discovery of one. The planet would have been a “super-Earth” – about eight times Earth’s mass. But the discovery was tentative. And several follow-ups found little evidence to support it. One concern was that the planet appeared to orbit the star once every 42 days. But that’s about the same period as the star’s rotation. And according to the 2024 study, that’s no coincidence. The earlier study had actually detected activity on the surface of the star. That activity looked like the signal of an orbiting planet. So a possible planet Vulcan vanished in the starlight. 40 Eridani is in the constellation Eridanus, the river. The star is in the southeast at nightfall, well to the upper right of Orion’s Belt. Under dark skies, the star is visible to the eye alone. Script by Damond Benningfield

Epsilon Eridani is the third-closest star system that’s visible to the unaided eye – just 10 and a half light-years away. It was among the first stars found to be encircled by a disk of dust. And it was one of two stars targeted in the first search for radio signals from other civilizations. The star itself is a little smaller and lighter than the Sun, and only a third as bright. It’s also billions of years younger than the Sun. Younger stars generate stronger magnetic fields. So Epsilon Eridani produces bigger magnetic storms than the Sun does, plus a much stronger “wind.” In 1983, a satellite discovered that the star is surrounded by a wide disk of dust. Later observations found several asteroid belts – bands filled with big chunks of rock and ice. Over the decades, astronomers have reported several possible planets. But only one of them has stuck. The planet is similar to Jupiter, the giant of our own solar system. In 1960, the star was considered a good candidate to host another civilization. So when Frank Drake launched Project Ozma to listen for radio signals, Epsilon Eridani was one of his two targets. He didn’t hear a peep – and neither has any search since then. Epsilon Eridani is well up in the south at nightfall, far to the right of the top right corner of Orion. The star isn’t all that bright, so you’ll need a starchart to pick it out. More about Eridanus tomorrow. Script by Damond Benningfield

The stars on the rim of the galaxy are going for a ride. They’re bobbing up and down like the horses on a merry-go-round. They’re also rippling outward, away from the center of the Milky Way. The Milky Way consists of a thin disk of stars and gas that spans a hundred thousand light-years or more. For decades, we’ve known that the rim of the disk is warped like the brim of a wide hat. It’s bent upward on one edge, and downward on the opposite edge. A recent study found that stars on those edges are moving along a big wave. Astronomers looked at the locations and motions of more than 20,000 bright young stars logged by the Gaia space telescope. The stars are as much as 45,000 light-years from the galactic center. Gaia found that the stars are bobbing up and down as much as a thousand light-years above or below the plane of the galaxy. And they appear to be sliding outward at thousands of miles per hour. The wave might have been created by a close approach of a smaller galaxy hundreds of millions of years ago. Its gravity disturbed the tranquility of the Milky Way’s outer precincts – sending the stars there for a ride. Under dark skies, the Milky Way is in good view tonight. In early evening, it extends along the body of Cygnus, the swan, in the west-northwest; through M-shaped Cassiopeia, higher in the sky; then down between Orion and the twins of Gemini, in the east-southeast. Script by Damond Benningfield

Almost 11 million years ago, a large asteroid slammed into Earth, somewhere around Australia. It could have gouged a crater more than 15 miles wide, and devastated life across tens of thousands of square miles. So far, though, the only traces of it are 14 tiny glass beads. Combined, they weigh just 53 grams – as much as a slice of bread. The beads are known as tektites. They formed from melted rock and sand that was blasted into the sky. Tiny blobs were shaped into balls by their passage through the air. Tektites are found all across the planet. Most of them are associated with a few major impacts. The region where a group of related tektites is found is called a strewn field. Five confirmed fields had been identified. One of them stretches across Australia and Asia. Decades ago, scientists identified eight tektites as members of that field, which was created by an impact about three-quarters of a million years ago. But a recent analysis found otherwise. Scientists conducted extensive studies of those beads, along with six others. They found that the beads were related to each other – but not to the known strewn field. Instead, they formed a new field, which stretches almost 600 miles across Australia. The beads are all the same age. So they formed in the same impact – 11 million years ago. But no one has yet found a crater – only a tiny handful of beads from a possible cosmic impact. Script by Damond Benningfield

Farmers in the American breadbasket are used to weather troubles: floods, droughts, hail, and more. But a storm in May of 2024 was something new. It caused machinery to go haywire during the peak of planting season. That caused an estimated 500 million dollars in losses. What was different about this storm was its source: the Sun. Massive outbursts of particles and energy bombarded Earth. That caused impressive displays of the northern lights. But it also messed with GPS satellites. From the central United States, GPS positions were off by more than 200 feet. That messed with farm equipment, disrupting the planting. A recent study said that such breaks could be more common in the decades ahead. The Sun goes through an 11-year cycle of storms. Big storms can cause all kinds of problems for modern technology. A couple of recent cycles were unusually quiet. And forecasts had called for the same from the current cycle, which peaked in 2024 and ’25. But those forecasts were wrong. The current cycle has been much more active than the previous ones, with many more sunspots than expected, and many more big outbursts. The recent study said that upcoming cycles could be even busier. The solar wind has been getting stronger since 2008 – an indication that the Sun is waking up from a “sleepy” period. So farmers – and the rest of us – could see more space weather problems in the decades ahead. Script by Damond Benningfield

Earth is getting fainter. For proof, just look at the Moon – something that scientists have been doing for decades. They’ve been looking at earthshine – sunlight reflected off of Earth. We see it lighting up the nighttime portion of the Moon – the part that’s not brightly lit by the Sun. It gives that part of the Moon a ghostly appearance. Right now, most of the lunar hemisphere that faces our way is in earthshine. The Moon is a thin crescent in the early morning sky. It’s getting thinner by the day as it wanes toward “new.” From the Moon, though, Earth is getting fatter. It’ll be “full” in just a couple of days. How bright Earth looks varies a good bit, depending on the exact distance, the amount of ice and cloud cover, and other factors. Clouds and ice are bright; land and oceans are dark. So as Earth turns on its axis, and different features rotate into view, earthshine goes up and down like a dining room light on a rheostat. Earthshine varies over longer periods as well, as a result of Earth’s changing climate. If cloud and ice coverage goes down, so does Earth’s overall brightness. And several studies have reported that that’s just what’s happening. Earthshine isn’t as bright as it was decades ago. The difference is small but clear – providing slightly darker nights on the Moon. Look for the Moon low in the sky before dawn tomorrow. The bright star Antares, the heart of the scorpion, is close by. Script by Damond Benningfield

Mighty Orion the hunter has a mighty resting spot for his tired feet: Cursa, the second-brightest star of Eridanus, the river. The star’s name comes from a longer Arabic phrase meaning “footstool of the central one” – Orion himself. As night falls, the star stands above Orion’s foot: Rigel, the hunter’s brightest star. Cursa is about 90 light-years away. It’s easy to see from that distance because it’s a giant. It’s several times the size and mass of the Sun, and 45 times the Sun’s brightness. Its classification as a “giant” tells us much more than just its size, though. It also tells us about its stage in life. A giant star has puffed up as a result of changes deep in its heart. It’s burned through the hydrogen in its core to make helium, so it’s moved into a new phase. In the case of Cursa, it’s fusing hydrogen in a thin shell around the core. The shell is quite hot, so it produces a lot of radiation. That pushes on the surrounding layers of gas, causing the star to expand. And that makes it brighter. Today, the surface of Cursa is thousands of degrees hotter than the Sun’s. At that temperature, the star shines almost pure white. As it continues to change, though, Cursa may get even bigger and brighter. But its surface will get cooler. So a bigger Cursa will shine redder – an angry-looking footstool for the hunter. Tomorrow: from giant to supergiant. Script by Damond Benningfield

Earth passed by Jupiter yesterday. Now, we’re beginning to leave the giant planet behind. We’ll loop past it again early next year. That passage is known as opposition – Jupiter lines up opposite the Sun in our sky. It’s closest to us then, so it shines brightest for the year. And it’s in view all night. Jupiter is much farther from the Sun than Earth is, so it takes about 12 years to complete a single orbit. Earth follows a much shorter path around the Sun, and it moves faster. So it passes Jupiter every 13 months. As we approach Jupiter, the planet stops its normal eastward motion against the background of stars. For a while, it moves backward – a period known as retrograde. Jupiter itself doesn’t change direction. Instead, the shift is a result of our changing viewing angle. It’s like passing a car on the highway. For a little bit, the other car looks like it’s moving in reverse compared to the background of buildings and trees. As the gap opens, though, it appears to resume its forward motion. Jupiter will reach that point on March 11th – shifting gears as it circles the Sun. Jupiter looks like a brilliant star – brighter than any other planet or star in the night sky now. The twin stars of Gemini are close by. Pollux, the brighter twin, is close to the left of Jupiter at nightfall. Castor is farther to the upper left. The whole group soars high across the south during the night. Script by Damond Benningfield

The closer we look at the worlds of the solar system, the more places we see that could be homes for life. Some of those worlds orbit Jupiter, the largest planet in the solar system. Jupiter itself isn’t on the list. It’s a big ball of gas with no solid surface. There has been speculation that large organisms could float through its skies. But that’s considered a long shot. It’s more likely that life could inhabit some of Jupiter’s moons. The leading candidate is Europa. It’s about the same size as our own moon. A deep ocean of liquid water probably lies below its icy crust. Plumes of hot water may squirt into the bottom of the ocean. The plumes would contain a variety of compounds – perhaps including the chemistry of life. So Europa has the right combination of water, heat, and chemistry to support life – at least microscopic life. Europa isn’t the only Jovian moon with a deep ocean. The largest moon, Ganymede, may have more liquid water than all Earth’s oceans combined. One other big moon may have an ocean as well. But the crusts of these moons are much thicker than Europa’s. So even if their oceans are inhabited, it’ll be much harder for us to find evidence of life. Look for Jupiter in the eastern sky in early evening, and arcing high across the sky later on. It looks like a brilliant star. Through binoculars, its big moons look like tiny stars quite close to the planet. More about Jupiter tomorrow. Script by Damond Benningfield