How A New Mission To Phobos Could Rewrite The History Of Mars – Forbes
When it comes to the worlds beyond Earth in our Solar System, it’s only natural to wonder whether our planet was alone in being home to native life. The fourth planet from the Sun, Mars, is a particularly interesting candidate, as there’s overwhelming evidence that its surface once possessed large amounts of liquid water, pooling in lakes, rivers, and even oceans. Long ago, we have every reason to suspect it had a thick atmosphere, temperate conditions, and even a third, inner, massive moon that dwarfed the other two — Phobos and Deimos — before falling back to Mars.
While Mars itself is vast, and any life that was once present has likely been extinct for billions of years, there’s a simple place to go to look for evidence of ancient processes that are easy to access: its innermost moon, Phobos. If we could gather material from the Phobian regiolith and bring it back here to Earth, we could analyze it and either confirm or challenge our best-supported ideas for the geological and chemical history of the red planet, and perhaps even find evidence for ancient life there. This isn’t a pipe dream, nor is it science fiction, but an actual mission approved and planned for launch in 2024: Martian Moons eXploration (MMX).
Upon its return to Earth in July of 2029, we’ll be able to analyze its samples, determining whether Mars was once home to life, whether Phobos was the result of a Martian impact or asteroid capture, and either confirming or rejecting a whole slew of hypotheses concerning Mars’s history. Here’s what we all should know.
If we rewind the clock all the way back to the first ~1 billion years of the Solar System, the inner planets likely would have looked very different to the way they appear today, some 4.6 billion years after our formation. Earth, although life was already present in its oceans, had an atmosphere that was rich in molecules like methane and ammonia, with very small amounts of oxygen: produced as the waste product of anaerobic lifeforms. Venus and Mars, meanwhile, may have both been similarly hospitable to life early on, as they were anticipated to have atmospheres similar in thickness and composition to Earth’s, with copious amounts of liquid water on the surface and the same raw ingredients — precursor molecules to life — that were present in large quantities on Earth.
While Venus and Mars are suspected to have had divergent histories from both Earth and one another, their early environments may have been extremely similar to Earth’s. As such, they may have possessed simple lifeforms in their early days just as Earth did. If we can investigate them in sufficient detail, we just might find the critical evidence that reveals that life may not have been unique to Earth, even within our own Solar System. While it might make sense to probe the planets themselves for such evidence, the billions of years that have subsequently passed may make such signals difficult to unambiguously extract. That’s where the potential of Mars’s innermost moon, Phobos, comes into play.
The Solar System isn’t a well-siloed environment, where “what happens on a planet stays on that planet.” Instead, it’s an active, dynamical place, where asteroids, centaurs, and comets routinely cross the orbits of the planets and moons. While gravitational interactions frequently occur, perturbing orbits, causing energy exchange, and leading to the ejection or capture of various bodies, there’s also a non-trivial possibility of having a collision between one of these fast-moving, low-mass bodies and a planet or moon. When such an impact event occurs, it not only creates a crater on the world and covers it in debris, but can also kick fragments of the world it impacts out into space.
Every rocky planet and moon in the Solar System that we’ve investigated up close and doesn’t rapidly refresh its surface — either through volcanic activity, like Jupiter’s moon Io, or through the turnover of ices and liquids, like Saturn’s Enceladus or Neptune’s Triton — shows copious evidence for both recent and ancient cratering. Mercury, Mars, the Moon, and Ganymede are covered in a rich array of craters of varying ages, and it’s known that these impacts can send debris from one region of the Solar System to elsewhere: in that planet’s orbit and beyond. In fact, of all the meteorites that have been recovered here on Earth, approximately 3% of them have been determined to be of Martian origin.
If impacts on Mars can routinely send Martian debris all the way to planet Earth, it would be an absurdity for the particulate debris from those impacts to not extend above the Martian atmosphere, where it would collide with and stick to the Martian moons: Phobos and Deimos. Throughout the history of Mars, collisions with Mars-crossing asteroids and comets should have produced copious amounts of impact events, delivering a substantial fraction of the ejected material to its moons. Being closer to Mars than outermost Deimos, Phobos is expected to have accrued more than 1 million tons of Martian material, now mixed into its regiolith.
Based on numerical simulations, the fraction of Martian material mixed into Phobos’s outermost layers should exceed ~1-part-in-1000, making this an excellent place to look for “dead biosignatures” of Martian origin. The researchers searching for such extinct clues to past life on Mars have named it SHIGAI, for Sterilized and Harshly Irradiated Genes and Ancient Imprints, which also means “dead remains” in Japanese. Despite the harsh environment of space and exposure to billions of years of solar wind and radiation, these remains should persist. By sampling and returning the cocktail of material collected from Phobos’s regiolith, scientists will be able to analyze material originating from different eras and different locations across the surface of Mars.
The MMX mission, developed by the Japanese Aerospace Exploration Agency (JAXA), has already been in the planning and development stages since its announcement in 2015. The plan is for it to softly land on Phobos at least once (and possibly twice, to get two different sample locations), to collect samples using a pneumatic system. Once a sufficiently large set of samples have been taken, it will take off once again, flying-by Deimos numerous times, observing it and Mars, and then sending the sample-containing Return Module back to Earth for analysis. The Return Module itself is expected to arrive on Earth in July of 2029.
If this sounds ambitious, that’s because it is. Only a very small set of missions have ever accomplished the joint feats of:
- traveling from Earth to another body in the Solar System,
- making a soft, controlled landing there,
- collecting samples from the object it landed on,
- successfully taking off once again,
- completing the journey back to Earth,
- and surviving atmospheric re-entry,
- so that the collected samples can be recovered an analyzed.
JAXA has been the world leader in endeavors such as this, with the Hayabusa and Hayabusa2 missions successfully returning samples from asteroids Itokawa and Ryugu: the first two sample return missions to be conducted since NASA’s Apollo program. While material is expected to be returned from Mars to Earth via the Mars Sample Return mission, the MMX mission should return the material collected from Phobos even earlier, providing the first return of Martian material, including the remains of possible organics, to Earth.
Depending on what arrives upon MMX’s return to Earth, we could uncover a view of Phobos that aligns with our current theories about its formation and history. Alternatively, we could receive a tremendous set of surprises that, quite literally, rewrites what we know about the history of Mars and the Martian planetary system. For example, like the other rocky planets present in our Solar System, we fully anticipate that Mars was born without moons of any type. After surviving the earliest phases of planet-formation in our youth, a major impact was suspected to occur, kicking up a large amount of debris that coalesced into three moons: a large, massive, innermost moon, with much-smaller Phobos orbiting exterior to that and Deimos comprising the final, outermost satellite.
Eventually, owing to both tidal forces and atmospheric drag, the innermost moon was disrupted and fell back to Mars, where it very likely created the large, asymmetric basin that accounts for the severe differences between the two hemispheres of Mars, as well as kicking up a tremendous amount of debris that could land on both Phobos and Deimos. If the material returned to Earth from Phobos matches up extraordinarily well with the material we’ve sampled and analyzed on the Martian surface — as determined by orbiters, landers, and rovers — the MMX mission could serve as a spectacular confirmation of this picture, strongly supported by simulations and the current evidence at hand.
However, it’s possible that the full suite of evidence is conspiring, at present, to mislead us about the origins of Phobos and Deimos. Perhaps there wasn’t a large, ancient impact on Mars that led to the origins of its moons; perhaps, instead, Phobos and Deimos are more like Saturn’s “oddball” moon Phoebe: a captured object, such as an asteroid, originating from elsewhere in the Solar System. While the orbits of Phobos and Deimos are extremely consistent with an origin from an ancient impact, their compositions and appearances appear to be quite asteroid-like. A sample return mission would reveal whether the composition of Phobos matches that of Mars or of the known types of asteroids.
It’s also possible that, despite its watery past and life-friendly early conditions, that life may not have ever arisen on the red planet. The evidence we have strongly indicates that over the first ~1+ billion years of the Solar System’s history, Mars possessed a thick atmosphere with large amounts of liquid water, and then transitioned — likely because of the death of its core’s magnetic dynamo — to become a low-pressure world where liquid water on its surface was impossible. The chemical imprints of such a scenario should appear frozen-in to the regiolith of Phobos if it occurred; if not, Phobos might reveal an alternative history, even one that’s entirely unexpected.
It might seem that sampling Mars, directly, is a far superior approach to sampling Phobos, but that’s not entirely true. As we can clearly see from orbiters, landers, and rovers, different locations on Mars have not only experienced substantially different histories, but leave different chemical fingerprints even today. The seasonal methane “burps” that we see coming from the ground don’t occur everywhere, but rather are limited in location and duration. Whenever we sample Mars directly and return its contents to Earth, we’re limited to whatever biomarkers — modern and ancient — are present at that specific location. If there’s life on Mars, but simply not in the location we’re sampling, we’ll miss it.
On the other hand, because impacts on Mars have occurred all over its surface and all throughout its history, the material of Martian origin that’s been deposited on Phobos means that the Phobian environment should truly provide a random sample of Mars. All possible Martian materials, from sedimentary to igneous rocks, covering all of Mars’s geological areas, should be present in some sort of quantity on Phobos. At the very least, the regiolith of Phobos should have significant contributions from several different regions and epochs on Mars. By collecting material from it and returning to Earth, we should get a random sample that provides insight into the planet-wide history of biological and chemical remnants on Mars, shedding light on any ancient life that may have existed there at one point.
There’s one more point that makes a sample return mission to Phobos so exciting: the comparably low degree of difficulty when compared to a sample return mission from Mars. First off, just like asteroids Itokawa and Ryugu, Mars’s moon Phobos is low enough in mass that it’s certainly covered in loosely-held rock, rubble, and dust, meaning that the instruments should have little difficulty in collecting the necessary material for a sample return. Second, the lack of any atmosphere and the extremely low surface gravity of Phobos should make gravitational escape extremely easy, compared to the difficulty of returning a sample from a world like Mars. Comparatively, a full-scale launch and return from the Martian surface — something never before attempted — is an exciting but risky proposition.
And finally, this would be the third attempt at an uncrewed sample return mission from a small-mass, airless body. It’s being performed by the same agency, JAXA, that has made the only two previous attempts: Hayabusa and Hayabusa2, both of which were successful. Ideally, both a Mars Sample Return mission and MMX, bringing back material from Phobos, will both be successful. But if you had to bet on only one, MMX has far fewer obstacles, and far fewer incidences of engineering problems that have never been reckoned with before, than a direct-from-Mars sample return.
It remains a fascinating and open question — perhaps the most interesting question we can ask about life beyond Earth in the Solar System — whether life ever existed on Mars. Although it’s a highly speculative proposition, it’s one that we have the potential to answer: not just down the road, but in the very near future. The combination of orbiters, landers, and rovers we have, both today and upcoming in the near-future mission timeline, will shed light on the presence and concentration of various biomarkers in the atmosphere, on Mars’s surface, and just beneath its surface. If the seasonal methane has a biological origin rather than a geochemical one, we should be able to know within a single decade.
When you fold in the upcoming sample return missions, from both Jezero Crater on Mars and from the surface of Phobos, we should become sensitive not only to the possibility of extant life on Mars, but of even ancient, now-extinct life. If life exists there now, these missions could teach us how such life first emerged and, later, evolved. If Mars was always devoid of life, these missions will provide valuable information in revealing why Mars is lifeless while Earth has always teemed with it. As always, the most important lesson is this: if we want to know what’s out there, the only way to find out is to look. With the Martian Moons eXplorer mission, the answers might be in our hands before the decade comes to a close.
Scientists discover mysterious cosmic threads in Milky Way – The Guardian
Astronomers have discovered hundreds of mysterious cosmic threads that point towards the supermassive black hole at the heart of the Milky Way, after a survey of the galaxy.
The strange filaments, each of which stretches five to 10 light years through space, resemble the dots and dashes of morse code on a vast scale. They spread out from the galactic centre 25,000 light years from Earth like fragmented spokes on an enormous wheel.
Farhad Yusef-Zadeh, an astronomer at Northwestern University in Evanston, Illinois, said he was “stunned” to discover the structures in data taken by the MeerKAT radio telescope in the Northern Cape of South Africa.
The observatory, the most sensitive radio telescope in the world, captured images of the threads during an unprecedented 200-hour survey of the galactic core. Yusef-Zadeh told the Guardian: “They all seem to trace back to the black hole. They are telling us something about the activity of the black hole itself.”
Four decades ago, Yusef-Zadeh found much larger, vertical filaments surrounding Sagittarius A*, the black hole at the centre of the Milky Way, in data gathered by another telescope called the Very Large Array in New Mexico. Those structures dangle perpendicular to the plane of the Milky Way disc and measure 150 light years from top to bottom.
What produced the more numerous vertical filaments is still unclear, but studies have found that they possess strong magnetic fields and emit radio waves as they accelerate particles in cosmic rays to the verge of light speed.
According to Yusef-Zadeh, researchers – himself included – have been so busy grappling with the nature of the giant vertical threads that the existence of the shorter, horizontal filaments which trace back to the centre of the Milky Way almost went unnoticed.
“The emphasis has been on understanding the vertical filaments. The horizontal structures somehow didn’t register,” Yusef-Zadeh said. “It was a surprise to suddenly find a new population of structures that seem to be pointing in the direction of the black hole. I was actually stunned when I saw these.”
“If it wasn’t for MeerKAT these wouldn’t have been detected,” he added. “We’ve never been able to dedicate that amount of time to the centre of the galaxy.
The shorter, horizontal threads that spread out from the centre of the Milky Way came into focus when the scientists removed the background and filtered noise from the MeerKAT images. Yusef-Zadeh believes the structures, described in the Astrophysical Journal Letters, formed through a different process to the larger, vertical filaments.
He suspects that an outburst of material from the black hole about 6m years ago slammed into surrounding stars and gas clouds, creating streaks of hot plasma that point back towards the black hole. The effect is akin to blowing blobs of paint across a canvas with a hairdryer.
“The outflow from the black hole interacts with the objects it meets and distorts their shape,” Yusef-Zadeh said. “It’s sufficient to blow everything in the same direction.”
By studying the cosmic threads, astronomers hope to understand more about the spin of the Milky Way’s central black hole and the accretion disc of infalling material that whirls around it.
“These are not going to be the last images of the centre of the galaxy,” said Yusef-Zadeh. “Our galaxy is rich in lots of structures that we can’t explain. There’s still a lot to be learned.”
James Webb Space Telescope finds water in super-hot exoplanet's atmosphere – Space.com
The James Webb Space Telescope has found traces of water vapor in the atmosphere of a super-hot gas giant exoplanet that orbits its star in less than one Earth day.
The exoplanet in question, WASP-18 b, is a gas giant 10 times more massive than the solar system‘s largest planet, Jupiter. The planet is quite extreme, as it orbits the sun-like star WASP-18, which is located some 400 light-years away from Earth, at an average distance of just 1.9 million miles (3.1 million kilometers). For comparison, the solar system’s innermost planet, Mercury, circles the sun at a distance of 39.4 million miles (63.4 million km).
Due to such close proximity to the parent star, the temperatures in WASP-18 b’s atmosphere are so high that most water molecules break apart, NASA said in a statement. The fact that Webb managed to resolve signatures of the residual water is a testament to the telescope’s observing powers.
Related: Exoplanets, dark matter and more: Big discoveries coming from James Webb Space Telescope, astronomers say
“The spectrum of the planet’s atmosphere clearly shows multiple small but precisely measured water features, present despite the extreme temperatures of almost 5,000 degrees Fahrenheit (2,700 degrees Celsius),” NASA wrote in the statement. “It’s so hot that it would tear most water molecules apart, so still seeing its presence speaks to Webb’s extraordinary sensitivity to detect remaining water.”
WASP-18 b, discovered in 2008, has been studied by other telescopes, including the Hubble Space Telescope, NASA’s X-ray space telescope Chandra, the exoplanet hunter TESS and the now-retired infrared Spitzer Space Telescope. None of these space telescopes, however, was sensitive enough to see the signatures of water in the planet’s atmosphere.
“Because the water features in this spectrum are so subtle, they were difficult to identify in previous observations,” Anjali Piette, a postdoctoral fellow at the Carnegie Institution for Science and one of the authors of the new research, said in the statement. “That made it really exciting to finally see water features with these JWST observations.”
In addition to being so massive, hot and close to its parent star, WASP-18 b is also tidally locked. That means one side of the planet constantly faces the star, just like the moon‘s near side always faces Earth. As a result of this tidal locking, considerable differences in temperature exist across the planet’s surface. The Webb measurements, for the first time, enabled scientists to map these differences in detail.
The measurements found that the most intensely illuminated parts of the planet can be up to 2,000 degrees F (1,100 degrees C) hotter than those in the twilight zone. The scientists didn’t expect such significant temperature differences and now think that there must be some not yet understood mechanism in action that prevents the distribution of heat around the planet’s globe.
“The brightness map of WASP-18 b shows a lack of east-west winds that is best matched by models with atmospheric drag,” co-author Ryan Challener, of the University of Michigan, said in the statement. “One possible explanation is that this planet has a strong magnetic field, which would be an exciting discovery!”
To create the temperature map, the researchers calculated the planet’s infrared glow by measuring the difference in the glow of the parent star during the time the planet transited in front of the star’s disk and then when it disappeared behind it.
“JWST is giving us the sensitivity to make much more detailed maps of hot giant planets like WASP-18 b than ever before,” Megan Mansfield, a Sagan Fellow at the University of Arizona and one of the authors of the paper describing the results. said in the statement. “This is the first time a planet has been mapped with JWST, and it’s really exciting to see that some of what our models predicted, such as a sharp drop in temperature away from the point on the planet directly facing the star, is actually seen in the data.”
The new study was published online Wednesday (May 31) in the journal Nature.
JWST Scans an Ultra-Hot Jupiter's Atmosphere – Universe Today
When astronomers discovered WASP-18b in 2009, they uncovered one of the most unusual planets ever found. It’s ten times as massive as Jupiter is, it’s tidally locked to its Sun-like star, and it completes an orbit in less than one Earth day, about 23 hours.
Now astronomers have pointed the JWST and its powerful NIRSS instrument at the ultra-Hot Jupiter and mapped its extraordinary atmosphere.
Ever since its discovery, astronomers have been keenly interested in WASP-18b. For one thing, it’s massive. At ten times more massive than Jupiter, the planet is nearing brown dwarf territory. It’s also extremely hot, with its dayside temperature exceeding 2750 C (4900 F.) Not only that, but it’s likely to spiral to its doom and collide with its star sometime in the next one million years.
Remove All Ads on Universe Today
Join our Patreon for as little as $3!
Get the ad-free experience for life
box-shadow: 0 0 .5rem black inset;
#go-ad-free div p
text-shadow: 2px 2px 5px rgba(0, 0, 0, 0.5);
#go-ad-free div p:first-child
@media (max-width: 940px)
#go-ad-free img, #go-ad-free div
margin: 0 auto;
For these reasons and more, astronomers are practically obsessed with it. They’ve made extensive efforts to map the exoplanet’s atmosphere and uncover its details with the Hubble and the Spitzer. But those space telescopes, as powerful as they are, were unable to collect data detailed enough to reveal the atmosphere’s properties conclusively.
Now that the JWST is in full swing, it was inevitable that someone’s request to point it at WASP-18b would be granted. Who in the Astronomocracy would say no?
In new research, a team led by a Ph.D. student at the University of Montreal mapped WASP-19b’s atmosphere with the JWST. They used the NIRISS instrument, one of Canada’s contributions to the JWST. The paper is “A broadband thermal emission spectrum of the ultra-hot Jupiter WASP-18b.” It’s published in Nature, and the lead author is Louis-Philippe Coulombe.
The researchers trained Webb’s NIRISS (Near-Infrared Imager and Slitless Spectrograph) on the planet during a secondary eclipse. This is when the planet passes behind its star and emerges on the other side. The instrument measures the light from the star and the planet, then during the eclipse, they deduct the star’s light, giving a measurement of the planet’s spectrum. The NIRISS’ power gave the researchers a detailed map of the planet’s atmosphere.
With the help of NIRISS, the researchers mapped the temperature gradients on the planet’s dayside. They found that the planet is much cooler near the terminator line: about 1,000 degrees cooler than the hottest point of the planet directly facing the star. That shows that winds are unable to spread heat efficiently to the planet’s nightside. What’s stopping that from happening?
“JWST is giving us the sensitivity to make much more detailed maps of hot giant planets like WASP-18 b than ever before. This is the first time a planet has been mapped with JWST, and it’s really exciting to see that some of what our models predicted, such as a sharp drop in temperature away from the point on the planet directly facing the star, is actually seen in the data!” said paper co-author Megan Mansfield, a Sagan Fellow at the University of Arizona.
The lack of winds moving the atmosphere around and regulating the temperature is surprising, and atmospheric drag has something to do with it.
“The brightness map of WASP-18 b shows a lack of east-west winds that is best matched by models with atmospheric drag,” said co-author Ryan Challener, a post-doctoral researcher at the University of Michigan. “One possible explanation is that this planet has a strong magnetic field, which would be an exciting discovery!”
In our Solar System, Jupiter has the strongest magnetic field. Scientists think that swirling conducting materials deep inside the planet, near its bizarre liquid, metallic hydrogen core generates the magnetic fields. The fields are so powerful that they protect the three Galilean moons from the solar wind. They also generate permanent aurorae and create powerful radiation belts around the giant planet.
But WASP-18 b is ten times more massive than Jupiter, and it’s reasonable to think its magnetic fields are even more dominant. If the planet’s magnetic field is responsible for the lack of east-west winds, it could be forcing the winds to move over the North Pole and down the South Pole.
The researchers were also able to measure the atmosphere’s temperature at different depths. Temperatures increased with altitude, sometimes by hundreds of degrees. They also found water vapour at different depths.
At 2,700 Celsius, the heat should tear most water molecules apart. The fact that the JWST was able to spot the remaining water speaks to its sensitivity.
“Because the water features in this spectrum are so subtle, they were difficult to identify in previous observations. That made it really exciting to finally see water features with these JWST observations,” said Anjali Piette, a postdoctoral fellow at the Carnegie Institution for Science and one of the authors of the new research.
But the JWST was able to reveal more about the star than just its temperature gradients and its water content. The researchers found that the atmosphere contains Vanadium Oxide, Titanium Oxide, and Hydride, a negative ion of hydrogen. Together, those chemicals could combine to give the atmosphere its opacity.
All these findings came from only six hours of observations with NIRISS. Six hours of JWST time is precious to astronomers, and that’s all the researchers needed. That’s not only because the JWST is so powerful and capable, but also because of WASP-18 b itself.
At only 400 light-years away, it’s relatively close in astronomical terms. Its proximity to its star also helped, and the planet is huddled right next to its star. Plus, WASP-18 b is huge. In fact, it’s one of the most massive planets accessible to atmospheric investigation.
The planet’s atmospheric properties also provide clues to its origins. Comparisons of metallicity and composition between planets and stars can help explain a planet’s history. WASP-18 b couldn’t have formed in its current location. It must have migrated there somehow. And while this work can’t answer that conclusively, it does tell us other things about the giant planet’s formation.
“By analyzing WASP-18 b’s spectrum, we not only learn about the various molecules that can be found in its atmosphere but also about the way it formed. We find from our observations that WASP-18 b’s composition is very similar to that of its star, meaning it most likely formed from the leftover gas that was present just after the star was born,” Coulombe said. “Those results are very valuable to get a clear picture of how strange planets like WASP-18 b, which have no counterpart in our Solar System, come to exist.”
Hannah Gadsby’s Disastrous ‘Pablo-matic’ Show at the Brooklyn Museum Has Some ‘Pablo-ms’ of Its Own – ARTnews
Why 20-year-olds should live with their parents, and a real estate recovery: This week's top real estate stories – The Globe and Mail
Letters to the editor: 'Many … are so concerned about the state of affairs in my province, yet they don't even live here … – The Globe and Mail
Silver investment demand jumped 12% in 2019
Iran anticipates renewed protests amid social media shutdown
Search for life on Mars accelerates as new bodies of water found below planet’s surface
Tech24 hours ago
Apple's AR/VR Headset Expected to Enter Mass Production in October Ahead of Late 2023 Launch – MacRumors
News24 hours ago
Man charged after allegedly threatening to shoot Toronto mayoral candidates, police say – CBC.ca
Real eState11 hours ago
‘All hell is going to break loose’: Property titan and Shark Tank star Barbara Corcoran says Elon Musk is right about commercial office space
News23 hours ago
Housing affordability in Canada just saw the biggest improvement in almost 4 years – Global News
Science24 hours ago
Scientists discover mysterious cosmic threads in Milky Way – The Guardian
Tech23 hours ago
Meta reveals the new Quest 3 VR headset with a $499.99 price tag – Space.com
Economy24 hours ago
Equities may rally since the U.S. economy remains strong: Dennis Mitchell – BNN Bloomberg
Media11 hours ago
OPEC denies media access to Reuters, Bloomberg, WSJ for weekend policy meets