Tag: Exoplanets

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Cosmic Space

The air of an alien world lifts hopes of detecting life

Blue exoplanet and red parent star in space
An artist's conception shows the exoplanet K2-18 b. (NASA / CSA / ESA / STScI / Cambridge U.)

Readings from NASA’s James Webb Space Telescope confirm the presence of carbon-based molecules including methane and carbon dioxide in the atmosphere of a distant planet known as K2-18 b — which supports previous suggestions that it might be the kind of ocean-covered world capable of harboring marine life.

K2-18 b, which was first detected in 2015 using data from NASA’s now-retired Kepler space telescope, lies in the habitable zone of a star system that’s about 120 light-years away in the constellation Leo. It’s about 8.6 times as massive as Earth, and astronomers regard it as a sub-Neptune — a type of planet that doesn’t exist in our solar system.

Since its initial detection, astrobiologists have been interested in the world’s potential for habitability. They suspected it might be what’s called a Hycean planet — a type of world that’s massive enough to hold onto a hydrogen-rich atmosphere and a globe-spanning sea. The evidence has been piling up: In 2019, researchers reported the chemical signature of water vapor and clouds in K2-18 b’s atmosphere.

The fact that JWST detected an abundance of methane (CH4) and carbon dioxide (CO2), along with a shortage of ammonia (NH3), is consistent with the atmospheric modeling for Hycean planets.

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Fiction Science Club

How we’ll find the first evidence of extraterrestrial life

Illustration: A variety of planets
Astronomers have detected thousands of planets, including dozens that are potentially habitable. (NASA Illustration)

When will we find evidence for life beyond Earth? And where will that evidence be found? University of Arizona astronomer Chris Impey, the author of a book called “Worlds Without End,” is betting that the first evidence will come to light within the next decade or so.

But don’t expect to see little green men or pointy-eared Vulcans. And don’t expect to get radio signals from a far-off planetary system, as depicted in the 1992 movie “Contact.”

Instead, Impey expects that NASA’s James Webb Space Telescope — or one of the giant Earth-based telescopes that’s gearing up for observations — will detect the spectroscopic signature of biological activity in the atmosphere of a planet that’s light-years away from us.

“Spectroscopic data is not as appealing to the general public,” Impey admits in the latest episode of the Fiction Science podcast. “People like pictures, and so spectroscopy never gets its fair due in the general talk about astronomy or science, because it’s slightly more esoteric. But it is the tool of choice here.”

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Fiction Science Club

Fiction looks into the far future of terraforming

Oceans on Mars
This illustration visualizes what an ocean-covered Mars might have looked like. (NASA/MAVEN/Lunar and Planetary Institute)

Billionaires such as Elon Musk and Jeff Bezos dream of making Mars more like Earth, or seeing millions of people living and working in space — but could such dreams ever be turned into reality?

In a new novel titled “The Terraformers,” science writer Annalee Newitz imagines that tens of thousands of years from now, future billionaires (who are likely to be quintillionaires by then) will figure out exactly how to tailor planets to their customers’ liking. Which wouldn’t necessarily be a good thing.

“There’s a lot of hand-wavy technologies that we would’ve had to have invented,” Newitz admits in the latest episode of the Fiction Science podcast. “You know, I do think it’s realistic that humans are going to eventually try to set up shop off Earth in some way. … So I think for me, the question is: terraforming in the name of what, and under the auspices of what organizations.”

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Cosmic Space

Webb Telescope captures its first photo of alien planet

This image shows the exoplanet HIP 65426 b in different bands of infrared light, as seen from the James Webb Space Telescope. In each of the infrared images, the planet's parent star is shown as a white five-pointed star. Credit: NASA/ESA/CSA, A. Carter (UCSC), the ERS 1386 team and A. Pagan (STScI).

NASA has released the first direct image of an exoplanet taken by the James Webb Space Telescope — and although there’s no chance that this particular alien world could harbor life as we know it, the picture serves as an early demonstration of the observatory’s power.

“We’ve only just begun,” Aarynn Carter, a researcher at the University of California at Santa Cruz who led the analysis of the JWST image, said today in a NASA image advisory. “There are many more images of exoplanets to come that will shape our overall understanding of their physics, chemistry and formation.”

The planet in question, HIP 65426 b, is about 355 light-years away in the constellation Centaurus. Discovered five years ago, it’s a gas giant that’s roughly seven times as massive as Jupiter — and it’s about 100 times farther out from its parent star than Earth is from the sun.

That extreme distance from a dwarf star would make HIP 65426 b a prohibitively chilly ball of gas. But the distance also provides enough separation for JWST to distinguish the planet from the star.

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Cosmic Space

Astronomers detect first hints of extragalactic planet

Suspected planet in M51
The white square highlights the suspected planet in M51. (NASA / CXC / SAO / DiStefano et al.; Optical: NASA / ESA / STScI / Grendler)

A blip recorded by the NASA’s Chandra X-ray Observatory has pointed astronomers to what might be a planet detected passing across a star in a galaxy beyond our own — but we may not know for sure anytime soon.

The observation of an X-ray transit in the spiral galaxy M51, about 28 million light-years away in the northern constellation Canes Venatici, is reported in the journal Nature Astronomy.

Even if the detection of a planet in M51 goes unconfirmed, the Chandra observations demonstrate that X-ray transits could become a new method for tracking planets far beyond our solar system.

“We are trying to open up a whole new arena for finding other worlds by searching for planet candidates at X-ray wavelengths, a strategy that makes it possible to discover them in other galaxies,” Rosanne Di Stefano of the Harvard-Smithsonian Center for Astrophysics, lead author of the newly published study, said in a news release.

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GeekWire

How the ‘Dune’ sci-fi saga parallels the science of dunes

Timothée Chalamet and Rebecca Ferguson in "Dune"
Timothée Chalamet and Rebecca Ferguson star in “Dune,” a movie based on sci-fi author Frank Herbert’s book. (Warner Bros. Photo)

The deserts of Abu Dhabi and Jordan play starring roles in the blockbuster sci-fi movie “Dune,” which premieres this week in theaters and on HBO Max — but the origins of the classic tale go back to a different set of dunes on the Oregon coast.

“Dune” creator Frank Herbert spent much of his life in the Pacific Northwest, from his childhood days in Tacoma to his stint as the Seattle Post-Intelligencer’s education editor. (When I worked at the P-I back in the 1980s, some of my fellow copy editors could still reminisce about Herbert’s habits.)

In 1957, Herbert spent some time researching what he hoped would be a magazine article about a U.S. Department of Agriculture project to stabilize the shifting sand dunes near Florence, Ore., by planting invasive beachgrass. The article was never finished, but according to “Dreamer of Dune,” a biography written by Herbert’s son Brian, the idea of transforming the dunes made a huge impression.

“Dad realized he had something bigger in front of him than a magazine article,” Brian Herbert wrote. “He sat back at his desk and remembered flying over the Oregon dunes in a Cessna. Sand. A desert world. He envisioned the earth without the technology to stop encroaching sand dunes, and extrapolated that idea until an entire planet had become a desert.”

From that initial thread of an idea, the elder Herbert wove six novels, published between 1965 and 1985. Since then, Brian Herbert and  longtime sci-fi collaborator Kevin J. Anderson have written more than a dozen of their own “Dune” sequels and prequels. (The latest was published just last month.)

The newly released movie covers just the first half of the original “Dune” novel. But in subsequent books, Herbert traced how fictional scientists tried to green up the desert planet of Arrakis — and how that brought about unanticipated, even problematic consequences.

Strangely enough, that part of the story parallels what’s now happening amid Oregon’s dunes. It’s a case of life imitating art … imitating life.

“It feels very extreme and sci-fi when you see it in a movie or in a book, but it’s also just like real U.S. government land management,” said Rebecca Mostow, a graduate research assistant at Oregon State University.

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Cosmic Space

Hubble uses eclipse to practice hunt for alien life

Hubble and lunar eclipse
An illustration shows the Hubble Space Telescope against the background of a total lunar eclipse. (NASA / ESA / M. Kornmesser)

Astronomers made use of the Hubble Space Telescope — and a total lunar eclipse — to rehearse their routine for seeking signs of life in alien atmospheres.

You’ll be relieved to know that the experiment, conducted on Jan. 20-21, 2019, determined that there are indeed signs of life on Earth.

The evidence came in the form of a strong spectral fingerprint for ozone. To detect that ultraviolet fingerprint, Hubble didn’t look at Earth directly. Instead, it analyzed the dim reddish light that was first refracted by Earth’s atmosphere, and then reflected back by the moon during last year’s lunar eclipse.

“Finding ozone is significant because it is a photochemical byproduct of molecular oxygen, which is itself a byproduct of life,” said Allison Youngblood of the Laboratory for Atmospheric and Space Physics in Boulder, Colo., lead researcher of Hubble’s observations.

Other ground-based telescopes made spectroscopic observations at other wavelengths during the eclipse. They were looking for the fingerprints of different atmospheric ingredients linked to life’s presence, such as oxygen and methane.

This wasn’t just an academic exercise. Astronomers hope future observatories, such as the James Webb Space Telescope and the Roman Space Telescope, will be able to detect life’s fingerprints in the atmospheres of faraway exoplanets. But that takes practice.

“One of NASA’s major goals is to identify planets that could support life,” Youngblood said in a Hubble news release. “But how would we know a habitable or an uninhabited planet if we saw one? What would they look like with the techniques that astronomers have at their disposal for characterizing the atmospheres of exoplanets? That’s why it’s important to develop models of Earth’s spectrum as a template for categorizing atmospheres on extrasolar planets.”

Check out the news release for further details, or delve into the research paper published today in The Astronomical Journal. And to learn more about how lunar eclipses work, check out this “Inconstant Moon” interactive (after you enable Flash in your browser).

This report was published on Cosmic Log. Accept no substitutes.

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GeekWire

Solving the case of the disappearing planet

More than a decade ago, Fomalhaut b was considered one of the first exoplanets to be directly imaged — but now it’s vanished, and scientists suspect it was actually nothing more than a huge cloud of dust created by a cosmic smashup.

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GeekWire

New Earth-sized planet ‘rescued’ from old data

Exoplanet
An artist’s conception shows Kepler-1649c orbiting around its host red dwarf star. (NASA / Ames Research Center Illustration / Daniel Rutter)

An alien Earth that just might be habitable has been discovered in years-old records, thanks to sharp-eyed astronomers who gave the data a second look.

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GeekWire

TESS adds new types of planets to its collection

TESS probe
An artist’s conception shows NASA’s Transiting Exoplanet Survey Satellite. (NASA Illustration)

Astronomers report that NASA’s Transiting Exoplanet Survey Satellite, or TESS, has detected its first Earth-sized planet lying in its parent star’s habitable zone, plus its first planet orbiting two stars.

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