Tag: space

We’ve Never Been Closer to Finding Life Outside Our Solar System

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In 2025, we might detect the first signs of life outside our solar system.

Crucial to this potential breakthrough is the 6.5-meter-diameter James Webb Space Telescope (JWST). Launched aboard an Ariane-5 rocket from Kourou, a coastal town in French Guiana, in 2021, the JWST is our biggest space telescope to date. Since it began collecting data, this telescope has allowed astronomers to observe some of the dimmest objects in the cosmos, like ancient galaxies and black holes.

Perhaps more importantly, in 2022, the telescope has also provided us with the first glimpses of rocky exoplanets inside what astronomers call the habitable zone. This is the area around a star where temperatures are just right for the existence of liquid water—one of the key ingredients of life as we know it—in the planet’s rocky surface. These Earth-sized planets were found orbiting a small red star called TRAPPIST-1, a star 40 light-years away with one-tenth of the mass of the sun. Red stars are cooler and smaller than our yellow sun, making it easier to detect Earth-sized planets orbiting around them. Nevertheless, the signal detected from exoplanets is typically weaker than the one emitted by the much brighter host star. Discovering these planets was an extremely difficult technical achievement.

The next stage—detecting molecules in the planets’ atmosphere—will be an even more challenging astronomical feat. Every time a planet passes between us and its star—when it transits—the starlight gets filtered by the planet’s atmosphere and hits the molecules in its path, creating spectral absorption features we can search for. These features are very difficult to identify. To accomplish that, the JWST will need to collect enough data from several planetary transits to suppress the signal from the host star and amplify the molecular features in the incredibly thin atmosphere of the rocky exoplanets (if you’d shrink these planets to the size of an apple, for instance, at that scale their atmosphere would be thinner than the fruit’s peel). However, with a space telescope as powerful as the JWST, 2025 might just be the year when we can finally detect these molecular signatures.

Detecting water in TRAPPIST-1’s exoplanets, however, is not our only chance to find life in faraway exoplanets. In 2024, for instance, the JWST also revealed potential signs of carbon dioxide and methane in the atmosphere of K2-18b, a planet located 124 light-years from Earth. K2-18b, however, is not a rocky, Earth-like planet orbiting its star in the Habitable zone. Instead, it’s more likely to be a giant gas ball with a water ocean similar to Neptune (albeit smaller in size). This means that if there’s life on K2-18b, it might be in a form completely different from life as we know it on Earth.

In 2025, the JWST will likely shed more light into these tantalizing detections, and hopefully confirm, for the first time ever, if there is life on alien worlds light-years away from our own.

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December 5, 2024
Exoplanet plate tectonics: A new frontier in the hunt for alien life

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Mark Garlick/Science Photo Library/Alamy

There is something strange about Earth. A few billion years ago, a process started here that we have never seen anywhere else. It completely reshaped the planet’s surface and its carbon cycle, sculpted new landscapes and has kept our home temperate and habitable for billions of years.

That process is plate tectonics, in which Earth continuously subsumes and reforms the slabs of its rocky outer shell. It is thought to be inextricably linked to habitability and perhaps an essential prerequisite for life itself. Without it, our lakes and rivers might have frozen or evaporated, the oceans could have been starved of nutrients and Earth’s climate would probably have veered into unlivable territory long ago. Life would have been in for a rough ride.

At least, that’s the idea. But it is tough to know whether plate tectonics is really crucial to Earth’s verdant ecology, given that we have nothing to compare it with. We know of no other planet that exhibits plate tectonics: among the four rocky planets in our solar system, Earth is the only one to recycle its crust in this way, and we haven’t spotted definitive signs of it beyond our solar system either.

Until recently, this was more or less where the story ended. But now, with the help of the James Webb Space Telescope (JWST), scientists are beginning to explore the geology of rocky worlds beyond our solar system. Finding one with plate tectonics will be a huge ask. But if we succeed, it could be the key to…

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December 2, 2024
The End Is Near for NASA’s Voyager Probes

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Saturn as captured by the Voyager program.

Smith Collection/Gado/Getty Images

Once the Voyagers’ planetary journeys were over, it was possible to begin a new mission phase. After their last planetary stops, both probes reached escape velocity for the solar system, allowing them to be released from the sun’s gravity. Since 2012 for Voyager 1, and 2018 for Voyager 2, they have become interstellar. We know this because after those dates, sensors on the probes showed that charged particles from the sun became less numerous and energetic than those detected from the galactic environment. This was a golden opportunity to study the boundaries of the solar system and the environment outside of it.

The Voyager 1 and 2 spacecraft carried Golden Records—recordings of sounds and images intended to show extraterrestrial beings the life and culture of Earth.

Space Frontiers/Getty Images

The Secret to a Long Life

Reaching such a distance is only possible with the right energy source. Many probes use solar panels, but if they move too far from the sun, they become useless (the farthest probe that uses them is the Juno probe orbiting Jupiter). The secret of the Voyagers lies in their atomic hearts: both are equipped with three radioisotope thermoelectric generators, or RTGs—small power generators that can produce power directly on board. Each RTG contains 24 plutonium-238 oxide spheres with a total mass of 4.5 kilograms.

Plutonium-238 is an unstable isotope, which means it undergoes radioactive decay. The plutonium atoms in the RTGs release alpha particles—comprising two protons and two neutrons—and these hit the RTG canister, heating it up. The heat is then converted into electricity.

An RTG built for the Voyager program.

NASA/JPL/Voyager

But as time passes, the plutonium on board is depleted, and so the RTGs produce less and less energy. The Voyagers are therefore slowly dying. Nuclear batteries have a maximum lifespan of 60 years.

In order to conserve the probes’ remaining energy, the mission team is gradually shutting down the various instruments on the probes that are still active. For example, in October, Voyager 2’s plasma science instrument—which measures electrically charged atoms passing the probe—was turned off; the same device on Voyager 1 was turned off in 2007 due to a malfunction. These instruments were used to study charged particles in the sun’s magnetic field, and it is precisely this detector in 2018 that determined that Voyager 2 had exited the heliosphere and become interstellar.

Four active instruments remain, including a magnetometer as well as other instruments used to study the galactic environment, with its cosmic rays and interstellar magnetic field. But these are in their last years. In the next decade—it’s hard to say exactly when—the batteries of both probes will be drained forever.

This story originally appeared on WIRED Italia and has been translated from Italian.

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December 2, 2024
The Mystery of How Supermassive Black Holes Merge

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However, modeling has shown that it is difficult to scatter enough stars toward the black holes to solve the final-parsec problem.

Alternatively, each black hole might have a small disk of gas around it, and these disks might draw in material from a wider disk that surrounds the empty region carved out by the holes. “The disks around them are being fed from the wider disk,” Taylor said, and that means, in turn, that their orbital energy can leak into the wider disk. “It seems a very efficient solution,” Natarajan said. “There’s a lot of gas available.”

In January, Blecha and her colleagues investigated the idea that a third black hole in the system could provide a solution. In some cases where two black holes have stalled, another galaxy could begin to merge with the first two, bringing with it an additional black hole. “You can have a strong three-body interaction,” Blecha said. “It can take away energy and greatly decrease the merger timescale.” In some scenarios, the lightest of the three holes is ejected, but in others all three merge.

Tests on the Horizon

The task now is to work out which solution is correct, or if multiple processes are at play.

Alonso-Álvarez hopes to test his idea by seeking a signal of self-interacting dark matter in upcoming pulsar timing array data. Once black holes get closer than the final parsec, they shed angular momentum primarily by emitting gravitational waves. But if self-interacting dark matter is at play, then we should see it sap some of the energy at distances around the parsec limit. This in turn would make for less energetic gravitational waves, Alonso-Álvarez said.

Hai-Bo Yu, a particle physicist at the University of California, Riverside who is a proponent of self-interacting dark matter, said the idea is plausible. “It’s an avenue to look for microscopic features of dark matter from gravitational wave physics,” he said. “I think that’s just fascinating.”

The European Space Agency’s Laser Interferometer Space Antenna (LISA) spacecraft, a gravitational wave observatory that’s set to launch in 2035, might give us even more answers. LISA will pick up the strong gravitational waves emitted by merging supermassive black holes in their final days. “With LISA we will actually see supermassive black holes merging,” Pacucci said. The nature of that signal could reveal “particular traits that show the slowing process,” solving the final-parsec problem.

Original story reprinted with permission from Quanta Magazine, an editorially independent publication of the Simons Foundation whose mission is to enhance public understanding of science by covering research developments and trends in mathematics and the physical and life sciences.

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December 1, 2024
The moon is just the beginning for this waterless concrete

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Building a home base on the moon will demand a steep supply of moon-based infrastructure: launch pads, shelter, and radiation blockers. But shipping Earth-based concrete to the lunar surface bears a hefty price tag. Sending just 1 kilogram (2.2 pounds) of material to the moon costs roughly $1.2 million, says Ali Kazemian, a robotic construction researcher at Louisiana State University (LSU). Instead, NASA hopes to create new materials from lunar soil and eventually adapt the same techniques for building on Mars.

Traditional concrete requires large amounts of water, a commodity that will be in short supply on the moon and critically important for life support or scientific research, according to the American Society of Civil Engineers. While prior NASA projects have tested compounds that could be used to make “lunarcrete,” they’re still working to craft the right waterless material.

So LSU researchers are refining the formula, developing a new cement based on sulfur, which they heat until it’s molten to bind material without the need for water. In recent work, the team mixed their waterless cement with simulated lunar and Martian soil to create a 3D-printable concrete, which they used to assemble walls and beams. “We need automated construction, and NASA thinks 3D printing is one of the few viable technologies for building lunar infrastructure,” says Kazemian.

A curved wall is 3D printed from waterless concrete.
COURTESY OF ALI KAZEMIAN

Beyond circumventing the need for water, the cement can handle wider temperature extremes and cures faster than traditional methods. The group used a pre-made powder for their experiments, but on the moon and Mars, astronauts might extract sulfur from surface soil.

To test whether the concrete can stand up to the moon’s harsh environment, the team placed its structures in a vacuum chamber for weeks, analyzing the material’s stability at different temperatures. Originally, researchers worried that cold conditions on the dark side of the moon might cause the compound to turn into a gas through a process called sublimation, like when dry ice skips its liquid phase and evaporates directly. Ultimately, they found that the concrete can handle the lunar South Pole’s frigid forecast without losing its form.

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November 29, 2024
Why Is It So Tricky to Show the Sun, Earth, and Moon in a Diagram?

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Earth, sun, moon: three objects in space whose interactions have a pretty big impact on our lives. Earth orbits the sun once a year, and it rotates on its axis about once a day (depending on your definition of “rotate”). This gives us the night-day sequence and the yearly cycle of the seasons.

The moon’s gravitational tug influences the tides. On a monthly cycle, we can also see the phases of the moon, which are caused by the relative positions of these three orbs. A full moon makes it possible to see at night. Before electric lights, this was a big deal.

You can see how these interactions structure our whole idea of time. So if you were writing a science textbook, you’d want to include an illustration of the Earth-sun-moon system, right? But guess what, you can’t. The distances and differences in size make it practically impossible.

Let’s say we want to build a model of the sun and Earth alone. Earth has a radius of about 6,371 kilometers (3,959 miles), but let’s represent this with a marble 1 centimeter in diameter. To keep things in scale, I’d have to use a giant beach ball for the sun—the kind people knock around at rock concerts—more than a meter in diameter. You could fit 1.3 million marbles into it.

But wait! It gets worse. That beach ball would also have to be 117 meters away. That’s longer than a football field. Now try to take a picture of the ball and the marble. Good luck with that.

Modeling the Earth and moon would be easier. If we use that marble for the moon, Earth would be a tennis ball, with a diameter of 6.7 centimeters. Now for the fun part. How far apart do you think we should put them? Take a guess. You’ll probably be wrong because we never see the Earth and moon together. The answer is 2 meters. Here’s what that would look like:

Illustration: Rhett Allain

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November 22, 2024
Having a baby on Mars? You may be in for a difficult time

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Mars – the kind of place to raise your kids?

ESA /MPS/OSIRIS/MPS/UPD/LAM/IAA/RSSD/INTA/UPM/DASP/IDA

As a kind of living embodiment of the dangers of techno-optimism, Elon Musk recently declared he means to create a self-sustaining settlement of 1 million people on Mars in the next 30 years. But few talk about the elephant in the room: “self-sustaining” means that women must become pregnant, give birth and somehow not die… on Mars.

Here on Earth – where we have breathable air, global supply chains, hospitals and medical specialists – UNICEF reports that in 2020 we lost 287,000 women to maternity-related deaths. A majority of these deaths occurred in areas where maternal care is hard to access. For example, in 2020 in the US, roughly 21 women per 100,000 died of maternity-related causes. In countries such as Chad, Nigeria and South Sudan, that number shoots to over 1000 per 100,000. And those are just deaths in the six weeks postpartum – morbidity rates continue to be elevated beyond this. So, let’s think about a place like Mars: 225 million kilometres from Earth, 40 per cent of Earth’s gravity, hardly any protection from space radiation, and planet-wide toxic dust storms. How do we think these astro-frontierswomen will fare?

Only about 15 per cent of astronauts have ever been women, so we currently have no data on pregnancy in space and little more on female astronauts overall. On Earth, well-timed hetero-coitus under ideal conditions has a roughly 25 per cent chance of producing a viable pregnancy. But it may not even be possible to get pregnant on Mars. Of the small amount of data we have, it seems that microgravity may impair the uterus’s ability to prepare for egg implantation. On Earth, you can improve rates with IVF, but SpaceX hasn’t released any plans to ship massive repro-labs. Maybe we should send astronauts with freezers full of frozen sperm, a turkey baster and a prayer?

If they should become pregnant despite it all, it is unlikely that conditions on Mars would be safe for maternal health. Microgravity in orbiting space stations is demonstrably bad for the musculoskeletal and cardiovascular systems: astronauts orbiting the Earth suffer bone loss, muscle atrophy and their vision degrades over time. Given that the heart changes shape in zero gravity, shifting from an ovoid to more of a fat sphere, and muscles that normally squeeze and support blood vessels atrophy, it is particularly worrying that mothers with pre-existing cardiovascular problems here on Earth are far more likely to experience severe morbidity or death.

Prenatal care can help. UNICEF presently recommends at least 4 visits to a healthcare provider during pregnancy. How will pregnant astronauts receive this minimum level of care? Perhaps they should all be board-certified maternal fetal medicine specialists with experience in field deliveries. Life-saving medications are a problem, too: the oxytocin needed to halt postpartum hemorrhaging has to be refrigerated at stable temperatures – add fridges to the launch list, then. And what if the fridges fail? The window for trips to Mars only opens once every two years, and it takes six months to get there from here. Even in perfect conditions, many medicines will expire well before resupply ships might arrive. It is also true that as many as 1 in 8 mothers suffer from postpartum depression. Because of the vast distance between Earth and Mars, calls with Earth providers will have up to a 20-minute time delay, so there will be no real-time conversations for rapid mental health support. Should we make all the astronauts psychiatrists, too?

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But there is a better way. Mars can be our next moonshot, but the technological payoff might not be about the rockets. We could use the excuse of Mars to deeply commit to research in women’s healthcare here on Earth, while also leaning into research on mammalian reproduction in space. Developing medications like shelf-stable oxytocin would immediately benefit women – right here, right now, on Earth. While the off-Earth environment may ultimately prove too dangerous for human pregnancy, fetuses could develop well in artificial wombs – if we can manage to build them. This technology could reduce maternal morbidity and mortality, while also giving women more choice.

Human pregnancy, birth and postpartum recovery without proper medical care results in so much pain and death. Not all the time, not every time, but an inexcusable amount of the time. We could choose to do better. If we’re unwilling to do it for women on Earth, let’s say we did it for Mars.

Kelly and Zach Weinersmith’s A City on Mars (Penguin) is the latest pick for the New Scientist Book Club: sign up here to read along with our members. Cat Bohannon is the author of Eve: How The Female Body Drove 200 Million Years of Human Evolution.

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November 22, 2024
Lake of Darkness review: This bold, experimental slice of deep-space sci-fi is just brilliant

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Something evil may be lurking in a black hole in Adam Roberts’s new novel

Liuzishan/Getty Images

Lake of Darkness
Adam Roberts (Gollancz)

I WAS recently asked for my definition of “hard science fiction” and I burbled something along the lines of “it has to have a lot of science in it, and also spaceships”. I’m not sure the spaceships bit is right. But if, for the sake of this article, my terrible definition is the one in play, then Lake of Darkness by Adam Roberts hits the mark 100 per cent.

In this case, the spaceships are two deep-space…

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November 20, 2024
Millions of phones create most complete map ever of the ionosphere

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Disturbances in the ionosphere can interfere with radio communication and satellite navigation

Shutterstock/buradaki

Data from millions of phones has helped produce the most complete map ever made of the ionosphere, part of Earth’s upper atmosphere. This could help us understand disturbances caused by geomagnetic storms and perhaps even improve GPS.

“Smartphone-based measurements cover twice as much of the ionosphere as traditional scientific monitoring stations,” says Brian Williams at Google Research. “It’s like there is a scientific monitoring station in every city where there are phones.”

Williams and…

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November 13, 2024
2024 Booker prize goes to Samantha Harvey’s novel Orbital, set over 24 hours on the ISS

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The International Space Station

MSFC/NASA

Samantha Harvey, who has won the UK’s top fiction award, the Booker prize, for her novel Orbital, has created a new genre: nature writing about space.

“I see it as a kind of space pastoral,” Harvey told the New Scientist podcast earlier in the year. “I wanted to see what you could do with words in a painterly way to try to conjure up that rapturous, joyful, extraordinary and also now somewhat grief-stricken view of the Earth.”

Orbital takes place over 24 hours on the International Space Station (ISS). There are six…

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November 12, 2024