The James Webb Space Telescope has investigated an exoplanet that’s super cool — literally. The huge planet, which is six times the mass of Jupiter, is the coldest exoplanet ever detected, with an average temperature of minus 87 degrees Celsius or minus 125 degrees Fahrenheit.
That makes the planet’s average temperatures around the same as the lowest temperature ever recorded on Earth, in Antarctica near the south pole during the dead of winter. So if you’re looking for a cozy place to visit for your holidays, even though Planet WD 1856+534 b is located just 81 light-years away, we wouldn’t recommend it.
The planet has an usually low temperature because of the star that it orbits. Even though the planet orbits close to its star, which would normally mean it has a high surface temperature, in this case the star it is orbiting is practically dead. The host star is a type called a white dwarf, which is the dense core that is left behind after a star has run out of fuel. When medium sized stars come to the ends of their lives, they shed off their outer layers and no longer create heat through fusion. However, there is still remaining heat in them, so they continue to cool over time.
White dwarfs are very common in our galaxy, so the fact that exoplanets can orbit them is important — it means that there could even be habitable worlds orbiting these dead stars.
The researchers from the University of Michigan, Ann Arbor, looking at this cold exoplanet weren’t sure if it would be possible for a planet to survive in this location. That’s because during the death of a star like this one, it puffs up to become a red giant before shrinking down to a core. If the planet had been in its current location during this time, it would have been engulfed by the red giant. Instead, the researchers think that the planet must have started off further out and then moved in closer to the star over time.
“WD 1856+534 b is now the first intact exoplanet confirmed within a white dwarf’s ‘forbidden zone,’ a region where planets would have been engulfed during the star’s red giant phase,” the researchers write. “Its presence provides direct evidence that planetary migration into close orbits — including the habitable zone — around white dwarfs is possible.”
The research will be published in The Astrophysical Journal Letters.
After 13 suborbital test flights and more than $15 billion in development costs, SpaceX's Starship has finally reached orbit. The 407-foot megarocket, the most powerful ever built, lifted off from Starbase, Texas, on Monday and delivered its first real payload on it's 14th attempt. The celebration came with an asterisk, though, since SpaceX had to cut the planned 10-hour mission to roughly three hours.
https://twitter.com/SpaceX/status/2104601695711904180
SpaceX is finally ready to give Starship its biggest test yet. The company says the massive rocket's 14th test flight is scheduled for September 22, when it will attempt to put the upper stage into Earth orbit for the first time. The launch is currently pending regulatory approval, with a 75-minute window opening at 7:15 a.m. CT.
Starship has 26 Starlink satellites to deliver
For decades, humanity has looked up at the Moon and wondered what it would be like to live on it. Think sprawling cities, factories, research centers, and permanent human settlements. Unfortunately, there is one fairly fundamental problem with that vision.
A new study published in Frontiers in Space Technologies argues that even the Moon's potentially enormous reserves of frozen water may be nowhere near enough to support city-sized populations sustainably. Researchers Martin Elvis and Jonathan McDowell estimate that the permanently shadowed regions near the lunar poles could contain roughly one billion tons of water. It sounds like an extraordinary amount until you put a million thirsty humans next to it.