Though global sea levels "varied little" for the 2,000 years before the 20th century, CNN reports that sea levels then "started rising and have not stopped since — and the pace is accelerating."

And sea level rise "was unexpectedly high last year, according to a recent NASA analysis of satellite data." More concerning, however, is the longer-term trend. The rate of annual sea level rise has more than doubled over the past 30 years, resulting in the global sea level increasing 4 inches since 1993. "It's like we're putting our foot on the gas pedal," said Benjamin Hamlington, a research scientist in the Sea Level and Ice Group at NASA's Jet Propulsion Laboratory. While other climate signals fluctuate, global sea level has a "persistent rise," he told CNN.

It spells trouble for the future. Scientists have a good idea how much average sea level will rise by 2050 — around 6 inches globally, and as much as 10 to 12 inches in the US. Past 2050, however, things get very fuzzy. "We have such a huge range of uncertainty," said Dirk Notz, head of sea ice at the University of Hamburg. "The numbers are just getting higher and higher and higher very quickly." The world could easily see an extra 3 feet of sea level rise by 2100, he told CNN; it could also take hundreds of years to reach that level. Scientists simply don't know enough yet to project what will happen.

What scientists are crystal clear about is the reason for the rise: human-caused global warming. Oceans absorb roughly 90% of the excess heat primarily produced by burning fossil fuels, and as water heats up it expands. Heat in the oceans and atmosphere is also driving melting of the Greenland and Antarctic ice sheets, which together hold enough fresh water to raise global sea levels by around 213 feet. Melting ice sheets have driven roughly two-thirds of longer-term sea level rise, although last year — the planet's hottest on record — the two factors flipped, making ocean warming the main driver. [SciTechDaily reports that between 2021 and 2023 the Antarctica ice sheet actually showed an overall increase in mass which exerted a negative contribution to sea level rise.]

It's likely that an increase of about 3 feet is already locked in, Notz said, because "we have pushed the system too hard." The big question is, how quickly will it happen? Ice sheets are the biggest uncertainty, as it's not clear how fast they'll react as the world heats up — whether they'll melt steadily or reach a tipping point and rapidly collapse... [I]t's still unclear how processes may unfold over the next decades and centuries. Antarctica is "the elephant in the room," he said. Alarming changes are unfolding on this vast icy continent, which holds enough water to raise levels by 190 feet.

Notz describes the ice sheet as an "awakening giant:" It takes a long time to wake up but once awake, "it's very, very difficult to put it back to sleep."
The article notes that U.S. coastlines "are tracking above global average and toward the upper end of climate model projections, NASA's Hamlington said." (The state of Louisiana has one of the highest rates of land loss in the world, with some places experiencing nearly 4x the global rate of relative sea level rise.) But it's not just a problem for America.

"Over the next three decades, islands such as Tuvalu, Kiribati and Fiji will experience at least 6 inches of sea level rise even if the world reduces planet-heating pollution, according to NASA.... "Entire villages in Fiji have been formally relocated," said Fijian activist George Nacewa, from climate group 350.org, "the incoming tides are flooding our roads and inundating our crops." However, if the pace accelerates rapidly, "it will be very, very difficult to adapt to, because things unfold too quickly," he said.
"Humans still have control over how fast sea level rises over the next decades and centuries by cutting emissions, Notz noted."

Thanks to long-time Slashdot reader RoccamOccam for sharing the news.

An anonymous reader quotes a report from the Associated Press: The European Union launched a drive on Monday to attract scientists and researchers to Europe with offers of grants and new policy plans, after the Trump administration froze U.S. government funding linked to diversity, equity and inclusion initiatives. "A few years ago, no one would have imagined that one of the biggest democracies in the world would cancel research programs under the pretext that the word diversity was in this program," French President Emmanuel Macron said at the "Choose Europe for Science" event in Paris. "No one would have thought that one of the biggest democracies in the world would delete with a stroke the ability of one researcher or another to obtain visas," Macron said. "But here we are."

Taking the same stage at the Sorbonne University, European Commission President Ursula von der Leyen said that the EU's executive branch would set up a "super grant" program aimed at offering "a longer-term perspective to the very best" in the field. She said that 500 million euros ($566 million) will be put forward in 2025-2027 "to make Europe a magnet for researchers." It would be injected into the European Research Council, which already has a budget of more than 16 billion euros ($18 billion) for 2021-2027.

Von der Leyen said that the 27-nation EU intends "to enshrine freedom of scientific research into law" with a new legal act. As "the threats rise across the world, Europe will not compromise on its principles," she said. Macron said that the French government would also soon make new proposals to beef up investment in science and research. [...] While not mentioning the Trump administration by name, von der Leyen said that it was "a gigantic miscalculation" to undermine free and open research. "We can all agree that science has no passport, no gender, no ethnicity, no political party," she said. "We believe that diversity is an asset of humanity and the lifeblood of science. It is one of the most valuable global assets and it must be protected." Macron said that science and research must not "be based on the diktats of the few."

Macron said that Europe "must become a refuge" for scientists and researchers, and he said to those who feel under threat elsewhere: "The message is simple. If you like freedom, come and help us to remain free, to do research here, to help us become better, to invest in our future."

Further reading:
75% of Scientists in Nature Poll Weigh Leaving US
NASA, Yale, and Stanford Scientists Consider 'Scientific Exile'

Astronomers may have found the best candidate yet for the elusive Planet Nine: a mysterious object in infrared sky surveys taken 23 years apart that appears to be more massive than Neptune and about 700 times farther from the sun than Earth. Space.com reports: [A] team led by astronomer Terry Long Phan of the National Tsing Hua University in Taiwan has delved into the archives of two far-infrared all-sky surveys in search of Planet Nine -- and incredibly, they have found something that could possibly be Planet Nine. The Infrared Astronomy Satellite, IRAS, launched in 1983 and surveyed the universe for almost a year before being decommissioned. Then, in 2006, the Japanese Aerospace Exploration Agency (JAXA) launched AKARI, another infrared astronomy satellite that was active between 2006 and 2011. Phan's team were looking for objects that appeared in IRAS's database, then appeared to have moved by the time AKARI took a look. The amount of movement on the sky would be tiny -- about three arcminutes per year at a distance of approximately 700 astronomical units (AU). One arcminute is 1/60 of an angular degree.

But there's an extra motion that Phan's team had to account for. As the Earth orbits the sun, our view of the position of very distant objects changes slightly in an effect called parallax. It is the same phenomenon as when you hold your index finger up to your face, close one eye and look at your finger, and then switch eyes -- your finger appears to move as a result of you looking at it from a slightly different position. Planet Nine would appear to move on the sky because of parallax as Earth moves around the sun. On any particular day, it might seem to be in one position, then six months later when Earth is on the other side of the sun, it would shift to another position, perhaps by 10 to 15 arcminutes -- then, six months after that, it would seem to shift back to its original position. To remove the effects of parallax, Phan's team searched for Planet Nine on the same date every year in the AKARI data, because on any given date it would appear in the same place, with zero parallax shift, every year. They then also scrutinized each candidate object that their search threw up on an hourly basis. If a candidate is a fast-moving, nearby object, then its motion would be detectable from hour to hour, and could therefore be ruled out. This careful search led Phan's team to a single object, a tiny dot in the infrared data.

It appears in one position in IRAS's 1983 image, though it was not in that position when AKARI looked. However, there is an object seen by AKARI in a position 47.4 arcminutes away that isn't there in the IRAS imagery, and it is within the range that Planet Nine could have traveled in the intervening time. In other words, this object has moved a little further along its orbit around the sun in the 23 or more years between IRAS and AKARI. The knowledge of its motion in that intervening time is not sufficient to be able to extrapolate the object's full orbit, therefore it's not yet possible to say for certain whether this is Planet Nine. First, astronomers need to recover it in more up-to-date imagery. [...] Based on the candidate object's brightness in the IRAS and AKARI images, Phan estimates that the object, if it really is Planet Nine, must be more massive than Neptune. This came as a surprise, because he and his team were searching for a super-Earth-size body. Previous surveys by NASA's Wide-field Infrared Survey Explorer (WISE) have ruled out any Jupiter-size planets out to 256,000 AU, and any Saturn-size planets out to 10,000 AU, but a smaller Neptune or Uranus-size world could still have gone undetected. Phan told Space.com that he had searched for his candidate in the WISE data, "but no convincing counterpart was found because it has moved since the 2006 position," and without knowing its orbit more accurately, we can't say where it has moved to. "Once we know the position of the candidate, a longer exposure with the current large optical telescopes can detect it," Phan told Space.com. "However, the follow-up observations with optical telescopes still need to cover about three square degrees because Planet Nine would have moved from the position where AKARI detected it in 2006. This is doable with a camera that has a large field of view, such as the Dark Energy Camera, which has a field of view of three square degrees on the Blanco four-meter telescope [in Chile]."

NASA's SPHEREx space observatory has officially begun its two-year mission to map the entire sky in 102 infrared wavelengths, capturing about 3,600 images daily to create 3D maps of hundreds of millions of galaxies. Its goal is to unlock new insights into cosmic inflation, the origins of galaxies, and the building blocks of life in the Milky Way by using spectroscopy to analyze light and matter across the universe. From a press release: From its perch in Earth orbit, SPHEREx peers into the darkness, pointing away from the planet and the Sun. The observatory will complete more than 11,000 orbits over its 25 months of planned survey operations, circling Earth about 14.5 times a day. It orbits Earth from north to south, passing over the poles, and each day it takes images along one circular strip of the sky. As the days pass and the planet moves around the Sun, SPHEREx's field of view shifts as well so that after six months, the observatory will have looked out into space in every direction.

When SPHEREx takes a picture of the sky, the light is sent to six detectors that each produces a unique image capturing different wavelengths of light. These groups of six images are called an exposure, and SPHEREx takes about 600 exposures per day. When it's done with one exposure, the whole observatory shifts position -- the mirrors and detectors don't move as they do on some other telescopes. Rather than using thrusters, SPHEREx relies on a system of reaction wheels, which spin inside the spacecraft to control its orientation.

Hundreds of thousands of SPHEREx's images will be digitally woven together to create four all-sky maps in two years. By mapping the entire sky, the mission will provide new insights about what happened in the first fraction of a second after the big bang. In that brief instant, an event called cosmic inflation caused the universe to expand a trillion-trillionfold.

Kosmos 482, a failed Soviet Venus probe, is expected to make an uncontrolled reentry in mid-May after orbiting Earth for 53 years. Gizmodo reports: The lander module from an old Soviet spacecraft is expected to reenter Earth's atmosphere during the second week of May, according to Marco Langbroek, a satellite tracker based in Leiden, the Netherlands. "As this is a lander that was designed to survive passage through the Venus atmosphere, it is possible that it will survive reentry through the Earth atmosphere intact, and impact intact," Langbroek wrote in a blog update. "The risks involved are not particularly high, but not zero."

Kosmos 482 launched on March 31, 1972 from the Baikonur Cosmodrome spaceport in Kazakhstan. The mission was an attempt by the Soviet space program to reach Venus, but it failed to gain enough velocity to enter a transfer trajectory toward the scorching-hot planet. A malfunction resulted in an engine burn that wasn't sufficient to reach Venus' orbit and left the spacecraft in an elliptical Earth orbit, according to NASA. The spacecraft broke apart into four different pieces, with two of the smaller fragments reentering over Ashburton, New Zealand, two days after launch. Meanwhile, two remaining pieces, believed to be the payload and the detached upper-stage engine unit, entered a higher orbit measuring 130 by 6,089 miles (210 by 9,800 kilometers).

The failed mission consisted of a carrier bus and a lander probe, which together form a spherical pressure vessel weighing more than 1,000 pounds (495 kilograms). Considering its mass, "risks are similar to that of a meteorite impact," Langbroek wrote. As of now, it's hard to determine exactly when the spacecraft will reenter. Langbroek estimates that the reentry will take place on May 10, but a more precise date will get clearer as the reentry date nears.

"Future moon astronauts may find water more accessible than previously thought," writes Space.com, citing a new NASA-led experiment: Because the moon lacks a magnetic field like Earth's, the barren lunar surface is constantly bombarded by energetic particles from the sun... Li Hsia Yeo, a planetary scientist at NASA's Goddard Space Flight Center in Maryland, led a lab experiment observing the effects of simulated solar wind on two samples of loose regolith brought to Earth by the Apollo 17 mission... To mimic conditions on the moon, the researchers built a custom apparatus that included a vacuum chamber, where the samples were placed, and a tiny particle accelerator, which the scientists used to bombard the samples with hydrogen ions for several days.

"The exciting thing here is that with only lunar soil and a basic ingredient from the sun — which is always spitting out hydrogen — there's a possibility of creating water," Yeo said in a statement. "That's incredible to think about." Supporting this idea, observations from previous moon missions have revealed an abundance of hydrogen gas in the moon's tenuous atmosphere. Scientists suspect that solar-wind-driven heating facilitates the combination of hydrogen atoms on the surface into hydrogen gas, which then escapes into space. This process also has a surprising upside, the new study suggests. Leftover oxygen atoms are free to bond with new hydrogen atoms formed by repeated bombardment of the solar wind, prepping the moon for more water formation on a renewable basis.

The findings could help assess how sustainable water on the moon is, as the sought-after resource is crucial for both life support and as propellant for rockets. The team's study was published in March in the journal JGR Planets .
NASA created a fascinating animation showing how water is released from the Moon during meteor showers. (In 2016 scientists discovered that when speck of comet debris vaporize on impact, they create shock waves in the lunar soil which can sometimes breach the dry upper layer, releasing water molecules from the hydrated layer below...)

Longtime Slashdot reader AmiMoJo shares a report from the BBC: China will let scientists from six countries, including the U.S., examine the rocks it collected from the Moon -- a scientific collaboration that comes as the two countries remain locked in a bitter trade war. Two NASA-funded U.S. institutions have been granted access to the lunar samples collected by the Chang'e-5 mission in 2020, the China National Space Administration (CNSA) said on Thursday. CNSA chief Shan Zhongde said that the samples were "a shared treasure for all humanity," local media reported.

Chinese researchers have not been able to access NASA's Moon samples because of restrictions imposed by U.S. lawmakers on the space agency's collaboration with China. Under the 2011 law, Nasa is banned from collaboration with China or any Chinese-owned companies unless it is specifically authorized by Congress. But John Logsdon, the former director of the Space Policy Institute at George Washington University, told BBC Newshour that the latest exchange of Moon rocks have "very little to do with politics." While there are controls on space technology, the examination of lunar samples had "nothing of military significance," he said. "It's international cooperation in science which is the norm."

To celebrate the Hubble Space Telescope's 35th anniversary in orbit, NASA and ESA released a series of new, out-out-of-this-world images spanning planets, nebulae, and galaxies. From a press release: Hubble today is at the peak of its scientific return thanks to the dedication, perseverance and skills of engineers, scientists and mission operators. Astronaut shuttle crews gallantly chased and rendezvoused with Hubble on five servicing missions from 1993 to 2009. The astronauts, including ESA astronauts on two of the servicing missions, upgraded Hubble's cameras, computers and other support systems.

By extending Hubble's operational life the telescope has made nearly 1.7 million observations, looking at approximately 55,000 astronomical targets. Hubble discoveries have resulted in over 22,000 papers and over 1.3 million citations as of February 2025. All the data collected by Hubble is archived and currently adds up to over 400 terabytes. The demand for observing time remains very high with 6:1 oversubscriptions, making it one of the most in-demand observatories today.

Hubble's long operational life has allowed astronomers to see astronomical changes spanning over three decades: seasonal variability on the planets in our solar system, black hole jets traveling at nearly the speed of light, stellar convulsions, asteroid collisions, expanding supernova bubbles, and much more.

NASA's oldest active astronaut, Don Pettit, celebrated his 70th birthday by returning to Earth after a seven-month mission aboard the ISS. The Guardian reports: A Soyuz capsule carrying the American and two Russian cosmonauts landed in Kazakhstan on Sunday, Pettit's birthday. "Today at 0420 Moscow time (0120 GMT), the Soyuz MS-26 landing craft with Alexei Ovchinin, Ivan Vagner and Donald (Don) Pettit aboard landed near the Kazakh town of Zhezkazgan," Russia's space agency Roscosmos said.

Spending 220 days in space, Pettit, Ovchinin and Vagner orbited the Earth 3,520 times and completed a journey of 93.3m miles over the course of their mission. It was the fourth spaceflight for Pettit, who has logged more than 18 months in orbit during his 29-year career. Nasa said in a statement that Pettit was "doing well and in the range of what is expected for him following return to Earth." A recording of the touchdown can be viewed here.

Earlier this year, Pettit managed to take one of the best photos ever captured from space. "When I first saw it, I was dazzled by its beauty," wrote Ars Technica's Eric Berger. "But when I looked further into the image, there were just so many amazing details to be found."

"In this image, one can see the core of the Milky Way galaxy, zodiacal light (sunlight diffused by interplanetary dust), streaks of SpaceX Starlink satellites, individual stars, an edge-on view of the atmosphere that appears in burnt umber due to hydroxide emissions, a near-sunrise just over the horizon, and nighttime cities appearing as streaks."

For the first time, astronomers have confirmed the existence of a lone black hole," reports Science News — "one with no star orbiting it." It's "the only one so far," says Kailash Sahu, an astronomer at the Space Telescope Science Institute in Baltimore. In 2022, Sahu and his colleagues discovered the dark object coursing through the constellation Sagittarius. A second team disputed the claim, saying the body might instead be a neutron star. New observations from the Hubble Space Telescope now confirm that the object's mass is so large that it must be a black hole, Sahu's team reports in the April 20 Astrophysical Journal.... [And that second team has revised its assessment and now agrees: the object is a black hole.]

While solitary black holes should be common, they are hard to find. The one in Sagittarius revealed itself when it passed in front of a dim background star, magnifying the star's light and slowly shifting its position due to the black hole's gravity. This passage occurred in July 2011, but the star's position is still changing. "It takes a long time to do the observations," Sahu says. "Everything is improved if you have a longer baseline and more observations." The original discovery relied on precise Hubble measurements of star positions from 2011 to 2017. The new work incorporates Hubble observations from 2021 and 2022 as well as data from the Gaia spacecraft.

The upshot: The black hole is about seven times as massive as the sun, give or take 0.8 solar masses.... Located 5,000 light-years from Earth, this black hole is much closer than the supermassive one at the Milky Way's center, which also lies in Sagittarius but about 27,000 light-years from us. The star-rich region around the galactic center provides an ideal hunting ground for solitary black holes passing in front of stars. Sahu hopes to find additional lone black holes by using the Nancy Grace Roman Space Telescope, slated for launch in 2027.

Billions of years ago Mars "had a warm, habitable climate with liquid water in lakes and flowing rivers," writes Ars Technica.

But "In order for Mars to be warm enough to host liquid water, there must have been a lot of carbon dioxide in the atmosphere," says Benjamin Tutolo, a researcher at the University of Calgary. "The question we've been asking for at least 30 years was where the record of all this carbon is." Tutolo led a new study of rock samples collected by the Curiosity rover that might have answered this question...

Curiosity rover was called Mars Science Laboratory for a reason. It went to the red planet fitted with a suite of instruments, some of which even the newer Perseverance was lacking. These enabled it to analyze the collected Martian rocks on the spot and beam the results back to Earth. "To get the most bang for the buck, NASA decided to send it to the place on Mars called the Gale Crater, because it was the tallest stack of sediments on the planet," Tutolo says. The central peak of Gale Crater was about 5 kilometers tall, created by the ancient meteorite impact... The idea then was to climb up Mount Sharp and collect samples from later and later geological periods at increasing elevations, tracing the history of habitability and the great drying up of Mars.

On the way, the carbon missed by the satellites was finally found...

It turned out the samples contained roughly between 5 and 10 percent of siderite... The siderite found in the samples was also pure, which Tutolo thinks indicates it has formed through an evaporation process akin to what we see in evaporated lakes on Earth. This, in turn, was the first evidence we've found of the ancient Martian carbon cycle. "Now we have evidence that confirms the models," Tutolo claims. The carbon from the atmosphere was being sequestered in the rocks on Mars just as it is on Earth. The problem was, unlike on Earth, it couldn't get out of these rocks... A large portion of carbon that got trapped in Martian rocks stayed in those rocks forever, thinning out the atmosphere.
"While it's likely the red planet had its own carbon cycle, it was an imperfect one that eventually turned it into the lifeless desert it is today," the article points out.

But the study still doesn't entirely explain what warmed the atmosphere of Mars — or why Martian habitability "was seemingly intermittent and fluctuating".

For combining machine learning with astronomy, high school senior Matteo Paz won $250,000 in the Regeneron Science Talent Search, reports Smithsonian magazine: The young scientist's tool processed 200 billion data entries from NASA's now-retired Near-Earth Object Wide-field Infrared Survey Explorer (NEOWISE) telescope. His model revealed 1.5 million previously unknown potential celestial bodies.... [H]e worked on an A.I. model that sorted through the raw data in search of tiny changes in infrared radiation, which could indicate the presence of variable objects.
Working with a mentor at the Planet Finder Academy at Caltech, Paz eventually flagged 1.5 million potential new objects, accoridng to the article, including supernovas and black holes.

And that mentor says other Caltech researchers are using Paz's catalog of potential variable objects to study binary star systems.

Thanks to long-time Slashdot reader schwit1 for sharing the article.

Astronomers have detected what may be the strongest evidence yet of extraterrestrial life on K2-18b, a massive exoplanet orbiting a star 120 light-years from Earth. The research team, led by Cambridge astronomer Nikku Madhusudhan, published their findings today in the Astrophysical Journal Letters.

Using the James Webb Space Telescope, researchers found significant concentrations of dimethyl sulfide and dimethyl disulfide in K2-18b's atmosphere. On Earth, these sulfur compounds are exclusively produced by living organisms, particularly marine algae. "It is in no one's interest to claim prematurely that we have detected life," said Madhusudhan, though he described the findings as "a revolutionary moment" and "the first time humanity has seen potential biosignatures on a habitable planet."

The team detected the signals during two separate observations, with the second showing an even stronger signature. Their analysis suggests K2-18b may be a "Hycean" planet -- covered with warm oceans and wrapped in a hydrogen-rich atmosphere -- with concentrations of dimethyl sulfide thousands of times higher than Earth levels.

Other scientists remain cautious. Christopher Glein of the Southwest Research Institute suggested K2-18b could instead be "a massive hunk of rock with a magma ocean and a thick, scorching hydrogen atmosphere." Further observations with Webb and future NASA telescopes will be necessary to confirm whether K2-18b is truly habitable or inhabited, though planned budget cuts may impact follow-up research.

Further reading: Water Found On a Potentially Life-Friendly Alien Planet (2019).

Blue Origin's New Shepard completed its 31st mission Monday morning, carrying the first all-female crew to space since Soviet cosmonaut Valentina Tereshkova's 1963 solo flight. The NS-31 mission lifted off from West Texas at 9:30 a.m. EDT, with hundreds of thousands watching via livestream as the autonomous vehicle crossed the Karman line 62 miles above Earth.

The 10-minute suborbital journey carried six passengers: journalist and Bezos' fiancee Lauren SÃnchez, former NASA scientist Aisha Bowe, bioastronautics researcher Amanda Nguyen, CBS journalist Gayle King, pop star Katy Perry, and film producer Kerianne Flynn. Bowe conducted three research experiments during the flight, while Nguyen became the first Vietnamese and Southeast Asian woman in space. The fully reusable New Shepard system features a pressurized capsule that separates from its booster before returning to Earth with three parachutes.

Nuclear fusion — which releases four times the energy of fission — could theoretically happen sooner in space than on earth, reports CNN.

"And it could help spacecraft achieve speeds of up to 500,000 miles (805,000 kilometers) per hour — more than the fastest object ever built..." With funding from the UK Space Agency, British startup Pulsar Fusion has unveiled Sunbird, a space rocket concept designed to meet spacecraft in orbit, attach to them, and carry them to their destination at breakneck speed using nuclear fusion... For now, Sunbird is in the very early stages of construction and it has exceptional engineering challenges to overcome, but Pulsar says it hopes to achieve fusion in orbit for the first time in 2027. [Pulsar's founder/CEO says the first functional Sunbird would be ready four to five years later.]

If the rocket ever becomes operational, it could one day cut the journey time of a potential mission to Mars in half.
CNN says the proposed Sunbird process would use helium-3 — which may be abundant on the Moon — to generate protons which "can be used as a 'nuclear exhaust' to provide propulsion". (And without generating any dangerous radioactive material.) "It's very unnatural to do fusion on Earth," says Richard Dinan, founder and CEO of Pulsar. "Fusion doesn't want to work in an atmosphere. Space is a far more logical, sensible place to do fusion, because that's where it wants to happen anyway...."

Sunbirds would operate similarly to city bikes at docking stations, according to Dinan: "We launch them into space, and we would have a charging station where they could sit and then meet your ship," he says. "You turn off your inefficient combustion engines, and use nuclear fusion for the greater part of your journey. Ideally, you'd have a station somewhere near Mars, and you'd have a station on low Earth orbit, and the (Sunbirds) would just go back and forth...." Initially, the Sunbirds will be offered for shuttling satellites in orbit, but their true potential would come into play with interplanetary missions. The company illustrates a few examples of the missions that Sunbird could unlock, such as delivering up to 2,000 kilograms (4,400 pounds) of cargo to Mars in under six months, deploying probes to Jupiter or Saturn in two to four years (NASA's Europa Clipper, launched in 2024 towards one of Jupiter's moons, will arrive after 5.5 years), and an asteroid mining mission that would complete a round trip to a near-Earth asteroid in one to two years instead of three.

Other companies are working on nuclear fusion engines for space propulsion, including Pasadena-based Helicity Space, which received investment from aerospace giant Lockheed Martin in 2024. San Diego-based General Atomics and NASA are working on another type of nuclear reactor — based on fission rather than fusion — which they plan to test in space in 2027.

"I started working on Voyager in 1977," the Voyager mission's project scientist told Gizmodo Saturday in a new interview. "It was my first job out of college."

35 years later, a Voyager probe became the first spacecraft to cross into interstellar space in 2012, with Voyager 2 following in 2018. But while each Voyager spacecraft carries 10 scientific instruments, all but three have now been turned off to conserve power, Gizmodo writes. "The two spacecraft now have enough power to operate for another year or so before engineers are forced to turn off two more instruments..." Voyager Mission Project Scientist Linda Spilker: The number of people that are working on and flying Voyager is a whole lot smaller than it was in the planetary days... The challenge was, can we reach the heliopause? We didn't know where it was, we had no idea how far away it was. We got to Neptune, and then we thought, "well, maybe it's just another 10 [astronomical units] or so, a little bit further, a little bit further." And so every time we got a little bit further, the modelers would go back, scratch their heads and say, "ah, it could be a little bit more, a little bit farther away," and so on and on that continued, until finally, Voyager 1 crossed the heliopause in 2012...

Gizmodo: Is it an emotional decision to turn off Voyager's instruments?

Spilker: I was talking to the cosmic ray instrument lead, and I said, "Wow, this must really be tough for you to see your instrument turned off." He helped build the instrument in the early 1970s. This instrument that's been sending you data, and that's been part of your life for over 50 years now. And he said, it was hard to think about turning it off for the whole team. It's kind of like losing a best friend, or someone that's been a part of your life for so many years, and then suddenly, it's silent. At the same time, there's this pride that you were part of that, and your instrument got so much great data — so it's a mix of emotions...

The spacecraft had a lot of redundancy on it, so that means two of every computer and two of all the key components. We've been able to turn off those backup units, but we're now at the point where, to really get a significant amount of power, all that's left are some of the science instruments to turn off. So, that's where we're at... How cold can the lines get before they freeze? How cold can some of these other components get before they stop working? So that's another challenge. Then there are individual tiny thrusters that align the spacecraft and keep that antenna pointed at the Earth so we can send the data back, and they're very slowly clogging up with little bits of silica, and so their puffs are getting weaker and weaker. That's another challenge that we're going through to balance.

But we're hopeful that we can get one, possibly two, spacecraft to the 50th anniversary in 2027. Voyager's golden anniversary, and perhaps even into the early 2030s with one, maybe two, science instruments.
"We're well past the warranty of four years..." Spilker says at one point. And "We're still working and thinking about an interstellar probe that would go much, much farther than Voyager.

"You're talking about a multi-generation mission."

The Starliner spacecraft lost four thrusters while approaching the International Space Station last summer. NASA astronaut, Butch Wilmore took manual control, remembers Ars Technica, "But as Starliner's thrusters failed, Wilmore lost the ability to move the spacecraft in the direction he wanted to go..." Starliner had flown to within a stone's throw of the space station, a safe harbor, if only they could reach it. But already, the failure of so many thrusters violated the mission's flight rules. In such an instance, they were supposed to turn around and come back to Earth. Approaching the station was deemed too risky for Wilmore and Williams, aboard Starliner, as well as for the astronauts on the $100 billion space station.

But what if it was not safe to come home, either?

"I don't know that we can come back to Earth at that point," Wilmore said in an interview. "I don't know if we can. And matter of fact, I'm thinking we probably can't."
After a half-hour exclusive interview, Ars Technica's senior space editor Eric Berger says he'd heard "a hell of a story." After Starliner lost four of its 28 reaction control system thrusters, Van Cise and this team in Houston decided the best chance for success was resetting the failed thrusters. This is, effectively, a fancy way of turning off your computer and rebooting it to try to fix the problem. But it meant Wilmore had to go hands-off from Starliner's controls. Imagine that. You're drifting away from the space station, trying to maintain your position. The station is your only real lifeline because if you lose the ability to dock, the chance of coming back in one piece is quite low. And now you're being told to take your hands off the controls...

Two of the four thrusters came back online.

Wilmore: "...But then we lose a fifth jet. What if we'd have lost that fifth jet while those other four were still down? I have no idea what would've happened. I attribute to the providence of the Lord getting those two jets back before that fifth one failed...

Berger: Mission Control decided that it wanted to try to recover the failed thrusters again. After Wilmore took his hands off the controls, this process recovered all but one of them. At that point, the vehicle could be flown autonomously, as it was intended to be.
"Wilmore added that he felt pretty confident, in the aftermath of docking to the space station, that Starliner probably would not be their ride home," according to the article. And Williams says it was the right decision. Publicly, NASA and Boeing expressed confidence in Starliner's safe return with crew. But Williams and Wilmore, who had just made that harrowing ride, felt differently.

This week NASA "issued a solicitation for the next two private astronaut missions to the International Space Station," reports Space News. Scheduled after May of 2026 and then mid-2027, "These will be the fifth and sixth such missions to the ISS, part of a broader low Earth orbit commercialization effort by NASA with the ultimate goal of replacing the International Space Station with one or more commercial stations."

NASA's Space Station program manager calls the missions "a key part" of helping industry partners "gain the experience needed to train and manage crews, conduct research, and develop future destinations." In short, they see the missions "providing companies with hands-on opportunities to refine their capabilities and build partnerships that will shape the future of low Earth orbit." [NASA's call for proposals] offers an opportunity to have future missions commanded by someone other than a former NASA astronaut. While companies must propose a commander who meets current requirements, it can also propose an alternate commander who is a former astronaut from the Canadian Space Agency, European Space Agency or Japan Aerospace Exploration Agency with similar ISS experience requirements... ["Broadening of this requirement is not guaranteed," NASA warns.]

That could allow some former astronauts already working with commercial spaceflight companies an opportunity to command private astronaut missions. Axiom Space, for example, announced in July 2024 that former ESA astronaut Tim Peake had joined its astronaut team. That came after Axiom and the U.K. Space Agency signed a memorandum of understanding in October 2023 to study the feasibility of a private astronaut mission crewed exclusively by U.K. astronauts.
So far Axiom Space has been awarded all four private astronaut missions, according to the article, "flying one mission each in 2022, 2023 and 2024. Its next mission, Ax-4, is scheduled for no earlier than May."

But "While Axiom has little or no competition for previous PAM awards, it will likely face stiffer competition this time. Vast, a company also planning to develop commercial space stations, has previously stated its intent to submit proposals..."

The Washington Post reports that after months of polar darkness, the extent of sea ice blanketing the Arctic this winter "fell to the lowest level on record, researchers announced this week... the smallest maximum extent in the 47-year satellite record, according to the National Snow and Ice Data Center.

"Since then, the ice has already begun to melt again." "Sea ice is acting like the old canary in the coal mine," Dartmouth University geophysicist Don Perovich said. "It's saying loud and clear that warming is occurring...."

In the summer, when the sun's radiation shines down on the Arctic for 24 hours a day, the ice acts as a shield, reflecting more than half of the light that hits it back into space.... With so little sea ice in the Arctic this year, more sunlight will be able to reach the open ocean, which absorbs more than 90 percent of the radiation that hits it. This will further warm the region, accelerating ice melt and exposing even more water to the light. This feedback loop helps explain the rapid warming of the Arctic, and it is expected to lead to a complete lack of summer sea ice in the region within decades, [said explained Melinda Webster, a sea ice scientist at the University of Washington]. The consequences would be dire for seals, polar bears and other wildlife, which depend on a stable sea ice platform to birth their young and hunt for food. It would also expose miles of coastline to pounding ocean waves, accelerating the erosion that threatens to tip some communities into the sea.

But the effects will also be felt in places far from the poles, Perovich said. Studies suggest that a complete loss of Arctic sea ice would raise global temperatures as much as adding a trillion tons of carbon dioxide to the atmosphere. Changes in the Arctic could also affect the jet stream, the river of winds that flows through the upper atmosphere, contributing to more extreme weather around the globe.

"What happens in the Arctic doesn't stay in the Arctic," Perovich said.
Earlier this year sea ice also fell 30% below the amount typical in the Antarctic prior to 2010, the researchers report. The total amount of sea ice on earth has now reached an all-time low, declining by more than a million square miles (2.5 million square kilometers) below the pre-2010 average.

"Altogether, Earth is missing an area of sea ice large enough to cover the entire continental United States east of the Mississippi."

Despite recent test failures, NASA has added SpaceX's Starship to its Launch Services Program contract, allowing it to compete for future science missions once it achieves a successful orbital flight. Florida Today reports: NASA announced the addition Friday to its current launch provider contract with SpaceX, which covers the Falcon 9 and Falcon Heavy. This opens the possibility of Starship flying future NASA science missions -- that is once Starship reaches a successful orbital flight.

"NASA has awarded SpaceX of Starbase, Texas, a modification under the NASA Launch Services (NLS) II contract to add Starship to their existing Falcon 9 and Falcon Heavy launch service offerings," NASA's statement reads. Th announcement is simply an onboarding of Starship as an option, as the contract runs through 2032. However, SpaceX is under pressure to get Starship operational by next year as the company plans not only to send an uncrewed Starship to Mars by late 2026, but the NASA Artemis III moon landing is fast approaching. Should it remain the plan with the current administration, Starship will act as a human lander for NASA's Artemis III crew.

"The NLS II contracts are multiple award, indefinite-delivery/indefinite-quantity, with an ordering period through June 2030 and an overall period of performance through December 2032. The contracts include an on-ramp provision that provides an opportunity annually for new launch service providers to add their launch service on an NLS II contract and compete for future missions and allows existing contractors to introduce launch services not currently on their NLS II contracts," NASA's statement reads.