US astronomy’s 10-year plan is super-ambitious

Its ‘decadal survey’ pitches big new space observatories, funding for large telescopes and a reckoning over social issues plaguing the field.

An observatory at night, shown with the stars "circling" the sky from a long exposure.

With input from many astronomers, ‘decadal surveys’ periodically help to set the priorities for US astronomy.Credit: Stan Honda/AFP via Getty

A long-anticipated road map for the next ten years of US astronomy is here — and it’s nothing if not ambitious.

It recommends that NASA coordinate, build and launch three flagship space observatories capable of detecting light over a broad range of wavelengths. It suggests that the US National Science Foundation (NSF) fund two enormous ground-based telescopes in Chile and possibly Hawaii, to try to catch up with an advanced European telescope that’s under construction. And for the first time, it issues recommendations for how federal agencies should fight systemic racism, sexism and other structural issues that drive people out of astronomy, weakening the quality of the science.

“There are tremendous scientific opportunities before us — twenty-first-century astrophysics is incredibly rich,” says Fiona Harrison, an astrophysicist at the California Institute of Technology in Pasadena and co-chair of the steering committee that wrote the report, known as Astro2020. The plan, released on 4 November, attempts to capitalize on some of those opportunities while also being realistic about budget and schedule constraints, she says.

How the fight over a Hawaii mega-telescope could change astronomy

US astronomy has sometimes taken a haphazard approach to building research facilities. Astro2020 is “imposing order on the field in a way that probably hasn’t been done before”, says Matt Mountain, president of the Association of Universities for Research in Astronomy in Washington DC. For instance, Astro2020 describes how the NSF could consider withdrawing its support from either of the large ground-based telescopes if they fail to reach certain milestones. It also sets out the deliberate steps NASA should take to develop technology for its ambitious space missions.

NASA, the NSF, the US Department of Energy (DOE) and the US Air Force commissioned the US National Academies of Sciences, Engineering, and Medicine to research and produce Astro2020. It is the latest in a series of ‘decadal surveys’ that aim to guide the direction of US astronomy and astrophysics, by gathering input from thousands of astronomers every ten years. “They’re influential because they really do let the whole community speak their voice,” says Aki Roberge, an astrophysicist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. Funding agencies generally follow the decadal survey’s recommendations, which means that billions of dollars are at stake.

Many astronomers welcome the vision laid out in the new report. “They really set the whole framework for how we can go about doing this ambitious science,” says Scott Gaudi, an astronomer at The Ohio State University in Columbus. “It’s a very balanced view,” adds Priyamvada Natarajan, an astrophysicist at Yale University in New Haven, Connecticut. “I like that they really acknowledge that it takes time for the science and technology for missions to mature.”

A forced partnership

Astronomers have been worried about the United States falling behind Europe, which is building the Extremely Large Telescope in Chile. Slated to come online in 2028, that facility is larger and further along than either of the extremely large US telescope projects under way. The 24.5-metre-wide Giant Magellan Telescope (GMT) is under construction in Chile, and the Thirty Meter Telescope (TMT) is planned for the Hawaiian mountain of Maunakea; Astro2020 recommends that the NSF buy into both of them, to help the country catch up.

A rendering of The Giant Magellan Telescope, currently being constructed at Las Campanas Observatory in Chile.

The Giant Magellan Telescope (artist’s rendering shown) is under construction in Chile.Credit: GMTO Corporation/M3 Engineering

Under this arrangement, the GMT and the TMT, once bitter rivals, would partner to cover skies in both the Northern and Southern hemispheres, which the European telescope cannot do. Together, they could make new types of astronomical discovery in galaxy evolution, exoplanet studies and other fields. “The only way to have astronomy in the United States be competitive at this scale is with this kind of capability,” says John O’Meara, chief scientist at the W. M. Keck Observatory in Kamuela, Hawaii.

The decadal survey’s recommendation would deliver a much-needed boost in funding: the GMT is estimated to cost at least US$2 billion and the TMT $2.6 billion, but neither has all the money it needs. Both began as privately funded projects. Buy-in from the US federal government — the NSF might consider investing $800 million in each — would give all US astronomers a chance to compete for a portion of observing time on both telescopes.

But it’s not clear whether the NSF could afford to support both facilities. So Astro2020 lays out a process for deciding whether to jettison one of the telescopes if need be.

NASA won’t rename James Webb telescope — and astronomers are angry

It remains to be seen how the TMT might move forward, however. The project is planned for Maunakea — one of the best sites in the world for stargazing — but construction there has been halted since 2015 owing to protests from Native Hawaiians, to whom the mountain is sacred. The TMT’s back-up site, on the island of La Palma in Spain’s Canary Islands, seemed to be knocked out of the running in July, when a court annulled the agreement that the TMT would need to build there. The project is appealing against the decision, but remains focused on building relationships at the preferred site in Hawaii, says Kerry Slater, the TMT’s vice-president of communications.

Other priorities on Astro2020’s wishlist for ground-based projects are a next-generation cosmology experiment in Antarctica and Chile that would probe the cosmic microwave background, commonly known as the afterglow of the Big Bang, and a major upgrade to the existing Very Large Array radio telescopes scattered across North America.

Triple threat

In addition to ground-based astronomy, the report provides guidance on the future of space-based missions, typically the most expensive and highest-profile astronomical observatories. Recommendations from previous decadal surveys have led to iconic spacecraft such as the Hubble Space Telescope. This time around, the top recommendation is to launch not one, but three flagship observatories, spanning different wavelengths of light to enable a variety of discoveries. The last time NASA coordinated projects in this way was between 1990 and 2003, when the agency launched four satellites dubbed the Great Observatories, beginning with Hubble.

A future NASA space telescope, recommended by Astro2020, could be a scaled-down version of this one, shown as an artist’s illustration.Credit: NASA GSFC

First out of the gate in the next set of missions, which some astronomers are calling the ‘New Great Observatories’, would be a space telescope similar to Hubble, but with a mirror more than twice the width of Hubble’s. It would detect light in ultraviolet, visible and near-infrared wavelengths, and be able to discover objects of astrophysical interest ranging from habitable planets to violent black holes. It would cost around $11 billion and launch in the early 2040s.

Second and third would be missions detecting X-rays, a sector of the electromagnetic spectrum in which some of the most powerful astrophysical phenomena can be observed, and far-infrared radiation, which can penetrate the shrouds of dust around newborn stars. These missions would cost $3 billion to $5 billion each, and a decision on whether to build them would be made five years after the start of the first Hubble-like mission.

Lurking behind these ambitious spacecraft is the spectre of previous space missions whose budgets have blown out of control. Neither of the top recommendations for large space-based missions from the past two decadal surveys are operational yet. The James Webb Space Telescope, the leading recommendation in the 2000 survey, is set to launch on 18 December, years later than intended, at a cost of nearly $10 billion — well above its original budget. The Nancy Grace Roman Space Telescope, the main recommendation in the 2010 survey, had to accommodate a 2.4-metre primary mirror donated by a spy-satellite programme, which was supposed to save money but required design changes and extra processing that drove up the cost. The COVID-19 pandemic added costs and delays, and Roman is now targeted to launch no earlier than 2027, at a cost of $4.3 billion.

Astronomy impasse: What’s next for the Thirty Meter Telescope?

“We’ve learned a lot in the course of the last 10–20 years about how to do large missions,” says Gaudi. “For me, it’s almost inconceivable that we couldn’t do better the next time, because we’ve learned from our past mistakes.”

Astro2020 recommends that NASA save money by, among other things, terminating the Stratospheric Observatory for Infrared Astronomy, a telescope-on-a-plane that has come under criticism for its relatively high operational price tag — nearly as much as Hubble’s — and relatively low scientific output so far, although that is improving. At the same time, the report advises that the agency fund mid-sized space missions, such as astrophysics spacecraft on the order of $1.5 billion each.

A human endeavour

Astro2020 also attempts to grapple with the importance of equity and inclusion to the health of US astronomy. “Astrophysics is done by humans,” says Jane Rigby, an astrophysicist at the Goddard centre. “How these humans treat each other, how they are led, how they hold each other accountable, what the policies and the systems are that they’re working in — this makes so much of a difference to the quality of the science that gets done.”

Hundreds of demonstrators gathered by the Maunakea Access Road in Hawaii to halt telescopes being built on sacred land.

Native Hawaiians have been protesting the construction of a new, extremely large telescope at Maunakea for years.Credit: Ronit Fahl/Zuma Press

US astronomy has found itself at the forefront of many social issues, such as the ethics of doing science on lands seized from Indigenous groups — such as Maunakea. The field has also faced widespread problems of sexism and racism in science, including a sexual harassment scandal surrounding prominent astronomer Geoff Marcy.

The report lays out some recommendations for reducing the systemic barriers that block many people from entering and staying in science. They include increasing federal funding for student and early-career researchers, making diversity a criterion in awarding grants, and gathering data to better track the lack of equity in funding. Collecting such data is the first crucial step towards distributing resources equitably, Natarajan says.

“Racial/ethnic diversity among astronomy faculty remains, in a word, abysmal,” the report says. Indigenous people are even more under-represented in astronomy than in other physical sciences, it notes, while calling for “a new model for respectful, collaborative decision-making in partnership with Indigenous and other local communities”.

NASA won’t rename James Webb telescope — and astronomers are angry

Attention will now turn to how the survey’s recommendations might become reality. Pandemic-related delays in the report’s release mean that the NSF, NASA and the DOE have already missed their chance to incorporate the findings into the budgets they are drawing up for the 2023 fiscal year. As a result, Astro2020 priorities will not start receiving funding until 2024 at the earliest. NASA says it will respond in detail to the recommendations within about ten weeks.

“It is now the community’s job to translate these words into actions,” says Tony Beasley, director of the National Radio Astronomy Observatory in Charlottesville, Virginia.

Source: https://www.nature.com/articles/d41586-021-03027-y?utm_source=Nature+Briefing&utm_campaign=d16d818218-briefing-dy-20211104&utm_medium=email&utm_term=0_c9dfd39373-d16d818218-46019854

INCREDIBLE: Scientists discover the first planet outside our Galaxy – in another galaxy!! – My Comments

[The state of Western science is insane. These distances are beyond imagination and all this equipment and these methods were invented by Whites. Just read this article and try to grasp the insane distances that are involved. The accuracy of our science is beyond imagination. Truly. Jan]

Astronomers have found hints of what could be the first planet ever to be discovered outside our galaxy.

Nearly 5,000 "exoplanets" – worlds orbiting stars beyond our Sun – have been found so far, but all of these have been located within the Milky Way galaxy.

The possible Saturn-sized planet discovered by Nasa’s Chandra X-Ray Telescope is in the Messier 51 galaxy.

This is located some 28 million light-years away from the Milky Way.

This new result is based on transits, where the passage of a planet in front of a star blocks some of the star’s light and yields a characteristic dip in brightness that can be detected by telescopes.

This general technique has already been used to find thousands of exoplanets.

Dr Rosanne Di Stefano and colleagues searched for dips in the brightness of X-rays received from a type of object known as an X-ray bright binary.

These objects typically contain a neutron star or black hole pulling in gas from a closely orbiting companion star. The material near the neutron star or black hole becomes superheated and glows at X-ray wavelengths.

Because the region producing bright X-rays is small, a planet passing in front of it could block most or all of the rays, making the transit easier to spot.

The team members used this technique to detect the exoplanet candidate in a binary system called M51-ULS-1.

"The method we developed and employed is the only presently implementable method to discover planetary systems in other galaxies," Dr Di Stefano, from the Harvard-Smithsonian Center for Astrophysics in Cambridge, US, told BBC News.

"It is a unique method, uniquely well-suited to finding planets around X-ray binaries at any distance from which we can measure a light curve."

The Chandra telescope was launched in 1999 to study X-ray emission from hot regions of the Universe

Future planet-hunting

This binary contains a black hole or neutron star orbiting a companion star with a mass about 20 times that of the Sun. A neutron star is the collapsed core of what had once been a massive star.

The transit lasted about three hours, during which the X-ray emission decreased to zero. Based on this and other information, the astronomers estimate that the candidate planet would be around the size of Saturn, and orbit the neutron star or black hole at about twice the distance Saturn lies from the Sun.

Dr Di Stefano said the techniques that have been so successful for finding exoplanets in the Milky Way break down when observing other galaxies. This is partly because the great distances involved reduce the amount of light which reaches the telescope and also mean that many objects are crowded into a small space (as viewed from Earth), making it difficult to resolve individual stars.

With X-rays, she said, "there may be only several dozen sources spread out over the entire galaxy, so we can resolve them. In addition, a subset of these are so bright in X-rays that we can measure their light curves.

"Finally, the huge emission of X-rays comes from a small region that can be substantially or (as in our case) totally blocked by a passing planet."

Messier 51 is also called the Whirlpool Galaxy because of its distinctive spiral shape

The researchers freely admit that more data is needed to verify their interpretation.

One challenge is that the planet candidate’s large orbit means it would not cross in front of its binary partner again for about 70 years, quashing any attempts to make a follow-up observation in the near-term.

One other possible explanation that the astronomers considered is that the dimming has been caused by a cloud of gas and dust passing in front of the X-ray source.

However, they think this is unlikely, because the characteristics of the event do not match up with the properties of a gas cloud.

"We know we are making an exciting and bold claim so we expect that other astronomers will look at it very carefully," said co-author Julia Berndtsson of Princeton University, New Jersey.

"We think we have a strong argument, and this process is how science works."

Dr Di Stefano said that the new generation of optical and infrared telescopes would not be able to compensate for the problems of crowding and dimness, so observations at X-ray wavelengths would likely remain the primary method for detecting planets in other galaxies.

However, she said a method known as microlensing might also hold promise for identifying extra-galactic planets.

The study has been published in the peer-reviewed journal Nature Astronomy.

Source: https://www.bbc.com/news/science-environment-59044650?utm_source=Nature+Briefing&utm_campaign=7a8f0a1880-briefing-dy-20211026&utm_medium=email&utm_term=0_c9dfd39373-7a8f0a1880-46019854

Science: Excellent: Exoplanet tally set to pass 4,000 mark – My Comments

[I have been following the topic of exo-planets – planets outside the solar system for some years now. The rate of discovery is picking up faster and faster. I suspect that when new specialised satellites get going, you'll see the pace of discoveries picking up EXPONENTIALLY FASTER. I suspect within a decade or two they'll be finding planets at insane speeds and the discoveries will run into the millions and later the billions – just like with stars. It's going to be incredible. Western science totally smokes. Jan]

The number of planets detected around other stars – or exoplanets – is set to hit the 4,000 mark.

The huge haul is a sign of the explosion of findings from searches with telescopes on the ground and in space over the last 25 years.

It’s also an indication of just how common planets are – with most stars in the Milky Way hosting at least one world in orbit around them.

That’s something astronomers couldn’t be certain of just 30 years ago.

The Extrasolar Planets Encyclopedia, run by the Observatoire de Paris, has already passed the 4,000 mark.

Dr Françoise Roques, from the observatory, who is on the scientific board of the encyclopedia, told BBC News: "The great news is that we shift from a starry sky to a planetary sky, as there are more planets than stars.

"And also that the planetary systems have great diversity of structure, with planets orbiting zero, one, two… stars, or other planets."

The Nasa Exoplanet Archive is 74 planets away from the milestone. But there are 443 planet candidates detected by Nasa’s Tess space telescope (launched in 2018) awaiting confirmation.

There are a further 2,423 candidates detected by the Kepler space telescope.

The latest exoplanet to be added to the Nasa archive was the Super Earth GI 686 b, which orbits a red dwarf star (a type cooler than our Sun) which was discovered using ground telescopes. It was added on 21 March.

The total number of confirmed planets differs between the two catalogues because of slightly different acceptance criteria – along with other factors.

The early technique of detecting new worlds by the "wobble" induced by a planet’s gravitational tug on its star yielded many giant planets known as "hot Jupiters", which orbited close to their stars. These planet types were easier to detect using the wobble method.

Nasa’s Kepler space telescope was launched in 2009; it used a different technique known as the transit method to measure the dip in brightness as a planet passed in front of its host star. Kepler discovered hundreds of Neptune-sized planets and those that fell into a category known as Super Earths (those having a mass larger than Earth’s but below those of Neptune-sized planets).

Dr Roques said it remained a difficult task to distinguish between a type of star known as a brown dwarf and giant planets.

"Four-thousand is just a number as the frontier of the planet domain is uncertain," she said.

"The brown dwarfs have been defined by the [IAU – International Astronomical
Union] as small stars, but in fact, some of them are big planets. Our database collects objects until 60 Jupiter masses and contains a mix of the planetary brown dwarfs (formed in a protoplanetary disk around a star) and starry brown dwarfs (formed by collapse of interstellar cloud).

"The only way to ensure the difference is to access its internal structure, which is a difficult/ impossible task."

The first exoplanets were found around a pulsar – a highly magnetised neutron star – in 1992 by Aleksander Wolszczan and Dale Frail.

The initial discovery of a planet around a main sequence star – those that fuse hydrogen into helium within their cores – was made in 1995 by astronomers Didier Queloz and Michel Mayor.

Dr Roque explained: "For the field of exoplanet exploration, we [are
going] from discovery projects to exploration projects, for a better understanding of the structure, formation, atmosphere and, of course habitability of exoplanets."

Source: https://www.bbc.com/news/science-environment-47681239

Photo: Earth has had TWO Moons for the last 3 years…

[This is quaint. We have pieces of rock that come into orbit and later leave. Jan]

Until recently, many of us earthlings were blissfully unaware that our planet had gained a second moon. But now 2020 CD3 has become such a superstar, we’re using giant telescopes just to catch a glimpse of it.

Part-time paparazzi, full-time astronomers at the Gemini Observatory in Hawaii snapped the stunning pictures of the car-sized carbonaceous rock using the 8-meter Gemini North telescope.

The image is actually a combination of three separate images using three different filters to capture our new natural satellite in all its glory.

"Obtaining the images was a scramble for the Gemini team because the object is quickly becoming fainter as it moves away from Earth," explains Gemini Observatory astronomer John Blakeslee, adding that the new celestial superstar 2020 CD3 is expected to leave us forever some time in April.

Fear not, as there are already rumors circulating of a new generation of mini-moons that could already be orbiting the Earth.

"We expect to find a population of these objects once the Rubin Observatory is operational," said Grigori Fedorets, the lead astronomer for the Gemini observations, referencing the Vera C. Rubin Observatory, whose sole purpose will be to scan the skies for similar, previously unknown, objects.

Source: https://www.rt.com/news/481914-astronomers-first-color-photo-minimoon/

Amazing Science: These 125 million-year-old fossils may hold dinosaur DNA – My Comments

[This is astounding. This normally is not possible. This is moving things to a whole new level as bits and pieces of older and older DNA is found … something previously impossible! So much can be learned from this. Jan]

The remnants of DNA may lurk in 125 million-year-old dinosaur fossils found in China. If the microscopic structures are indeed DNA, they would be the oldest recorded preservation of chromosome material in a vertebrate fossil.

DNA is coiled inside chromosomes within a cell’s nucleus. Researchers have reported possible cell nucleus structures in fossils of plants and algae dating back millions of years. Scientists have even suggested that a set of microfossils from 540 million years ago might hold preserved nuclei.

These claims are often controversial, because it can be hard to distinguish a fossilized nucleus from a random blob of mineralization created during the fossilization process. In the new study, published Sept. 24 in the journal Communications Biology, researchers compared fossilized cartilage from the feathered, peacock-size dinosaur Caudipteryx with cells from modern chickens; they found structures in the fossils that looked much like chromatin, or threads of DNA and protein.

"The fact that they are seeing this is really interesting, and it suggests we need to do more research as to what happens to DNA and chromosomes after cell death," said Emily Carlisle, a doctoral student who studies microscopic fossils and their preservation at the University of Bristol in England but was not involved in the new research.

To answer the obvious burning question: No, we’re nowhere close to resurrecting dinosaurs from their fossilized DNA.

"If there is any DNA or DNA-like molecule in there, it will be — as a scientific guess — very, very chemically modified and altered," Alida Bailleul, a paleobiologist at the Chinese Academy of Sciences who led the new research, wrote in an email to Live Science.

However, Bailleul said, if paleontologists can identify chromosome material in fossils, they may someday be able to unravel snippets of a genetic sequence. This could reveal a little more about dinosaur physiology.

But first, researchers have to find out if the DNA is even there. Until recently, most paleontologists thought that rot and decay destroyed the contents of cells before fossilization could take hold. Any microscopic structures inside cells were considered collapsed cell contents, such as organelles and membranes, that had rotted before mineralization, Carlisle told Live Science. More recently, though, paleontologists have found legitimate cell structures in a few fossils. For example, 190 million-year-old fern cells described in 2014 in the journal Science were buried in volcanic ash and fossilized so quickly that some were frozen in the process of cell division. Unmistakable chromosomes are visible in some of these cells.

In 2020, Bailleul and her colleagues reported the possible preservation of DNA in the skull of an infant Hypacrosaurus, a kind of duck-billed dinosaur that lived 75 million years ago, found in Montana. The possible DNA was found in cartilage, the connective tissue that makes up the joints.

For the new study, the researchers turned to a well-preserved specimen of Caudipteryx held by the Shandong Tianyu Museum of Nature in China. Originally discovered in the northeastern province of Liaoning, the fossil has ample preserved cartilage, which the researchers stained with the same dyes used to image DNA in modern tissue. These dyes bind to DNA and turn it a specific color, depending on the dye, allowing the DNA to stand out against the rest of the nucleus. By examining the stained, fossilized cartilage with several microscopy methods, Bailleul and her team showed that the cartilage cells contain structures that look just like nuclei with a scramble of chromatin inside.

The stained dinosaur nuclei’s resemblance to modern cells doesn’t prove there is DNA inside them, though, Bailleul cautioned. "What it means is that there are definitely parts of original organic molecules, perhaps some original DNA in there, but we don’t know that yet for sure," she said. "We just need to go figure out exactly what these organic molecules are."

The imaging definitely seems to show nuclei, Carlisle said, but it’s harder to identify fossilized chromosomes, because no one really knows what happens to chromosomes as they decay. It’s possible that the contents of the nucleus might just collapse into structures that look like chromosomes but are really just a jumble of meaningless mineralized junk; it’s also possible that the fossilization process preserves some of the original molecular structure. (One 2012 study suggests that DNA in bone will completely break down in about 7 million years, but the timing may depend heavily on environmental factors.)

"It would be really interesting to do more experiments into that, looking at what happens inside the nuclei instead of just what happens to it from the surface," Carlisle said.

Bailleul and her colleagues hope to collect more chemical data to nail down the identity of the mysterious structures.

"I hope we can reconstruct a sequence, someday, somehow," she said. "Let’s see: I could be wrong, but I could also be right."

Source: https://www.livescience.com/dinosaur-dna-fossils.html?utm_source=SmartBrief&utm_medium=email&utm_campaign=368B3745-DDE0-4A69-A2E8-62503D85375D&utm_content=FDA2F203-A8D8-4A6F-8372-A21AA22D887C&utm_term=23709803-d360-4259-9c73-be4ff46b5c71

Science: New type of dark energy could solve Universe expansion mystery

Hints of a previously unknown, primordial form of the substance could explain why the cosmos now seems to be expanding faster than theory predicts.

Data from the Atacama Cosmology Telescope suggest the existence of two types of dark energy at the very start of the Universe.

Cosmologists have found signs that a second type of dark energy — the ubiquitous but enigmatic substance that is pushing the current Universe’s expansion to accelerate — might have existed in the first 300,000 years after the Big Bang.

Two separate studies — both posted on the arXiv preprint server in the past week 1,2 — have detected a tentative first trace of this ‘early dark energy’ in data collected between 2013 and 2016 by the Atacama Cosmology Telescope (ACT) in Chile. If the findings are confirmed, they could help to solve a long-standing conundrum surrounding data about the early Universe, which seem to be incompatible with the rate of cosmic expansion measured today. But the data are preliminary and don’t show definitively whether this form of dark energy really existed.

“There are a number of reasons to be careful to take this as a discovery of new physics,” says Silvia Galli, a cosmologist at the Paris Institute of Astrophysics.

The authors of both preprints — one posted by the ACT team, and the other by an independent group — admit that the data are not yet strong enough to detect early dark energy with high confidence. But they say that further observations from the ACT and another observatory, the South Pole Telescope in Antarctica, could provide a more stringent test soon. “If this really is true — if the early Universe really did feature early dark energy — then we should see a strong signal,” says Colin Hill, a co-author of the ACT team’s paper1 who is a cosmologist at Columbia University in New York City.

Mapping the CMB

Both the ACT and the South Pole Telescope are designed to map the cosmic microwave background (CMB), primordial radiation sometimes described as the afterglow of the Big Bang. The CMB is one of the pillars of cosmologists’ understanding of the Universe. By mapping subtle variations in the CMB across the sky, researchers have found compelling evidence for the ‘standard model of cosmology’. This model describes the evolution of a Universe containing three primary ingredients: dark energy; the equally mysterious dark matter, which is the primary cause of the formation of galaxies; and ordinary matter, which accounts for less than 5% of the Universe’s total mass and energy.

Current state-of-the-art CMB maps were provided by the European Space Agency’s Planck mission, which was active between 2009 and 2013. Calculations based on Planck data predict — assuming that the standard model of cosmology is correct — exactly how fast the Universe should be expanding now. But for the past decade or so, increasingly accurate measurements of that expansion, based on observations of supernova explosions and other techniques, have found it to be 5–10% faster3.

How fast is the Universe expanding? Cosmologists just got more confused

Theorists have suggested a plethora of modifications to the standard model that could explain this difference. Two years ago, cosmologist Marc Kamionkowski at Johns Hopkins University in Baltimore, Maryland, and his collaborators suggested an extra ingredient for the standard model4. Their ‘early dark energy’ — which made more precise an idea that they and other teams had been working on for several years — would be a sort of fluid that permeated the Universe before withering away within a few hundred thousand years of the Big Bang. “It’s not a compelling argument, but it’s the only model we can get to work,” says Kamionkowski.

Early dark energy would not have been strong enough to cause an accelerated expansion, as ‘ordinary’ dark energy is currently doing. But it would have caused the plasma that emerged from the Big Bang to cool down faster than it would have otherwise. This would affect how CMB data should be interpreted — especially when it comes to measurements of the age of the Universe and its rate of expansion that are based on how far sound waves were able to travel in the plasma before it cooled into gas. Planck and similar observatories use features that were left in the sky after this transition to make such calculations.

The two latest studies find that the ACT’s map of the CMB’s polarization fits better with a model including early dark energy than with the standard one. Interpreting the CMB on the basis of the early dark energy model and ACT data would mean that the Universe is now 12.4 billion years old, about 11% younger than the 13.8 billion years calculated using the standard model, says Hill. Correspondingly, the current expansion would be about 5% faster than the standard model predicts — closer to what astronomers calculate today.

Inconsistencies remain

Hill says that he was previously sceptical about early dark energy, and that his team’s findings surprised him. Vivian Poulin, an astrophysicist at the University of Montpellier in France and a co-author of the second study2 based on ACT data, says it was reassuring that his team’s analysis agreed with the ACT team’s own. “The lead authors are very, very hard-nosed, conservative people, who really understand the data and the measurements,” Kamionkowski says.

But Galli warns that the ACT data seem to be inconsistent with calculations by the Planck team, which she was part of. And although the ACT’s polarization data might favour early dark energy, it is unclear whether its other major set of data — its map of CMB temperatures — shows such a preference. For these reasons, she adds, it will be crucial to cross-check the results using the South Pole Telescope, an experiment she is part of.

Wendy Freedman, an astronomer at the University of Chicago in Illinois who has contributed to some of the most precise measurements of cosmic expansion, says that the ACT-based results are interesting, if preliminary. “It is important to pursue different models” and compare them with the standard one, she says.

doi: https://doi.org/10.1038/d41586-021-02531-5

Source: https://www.nature.com/articles/d41586-021-02531-5?utm_source=Nature+Briefing&utm_campaign=51bb877e21-briefing-dy-20210917&utm_medium=email&utm_term=0_c9dfd39373-51bb877e21-46019854

Science: Curiosity rover discovers that evidence of past life on Mars may have been erased

The surprising discovery doesn’t make it any less likely that scientists will find life on the Red Planet.

Evidence of ancient life may have been scrubbed from parts of Mars, a new NASA study has found.

The space agency’s Curiosity rover made the surprising discovery while investigating clay-rich sedimentary rocks around its landing site in Gale Crater, a former lake that was made when an asteroid struck the Red Planet roughly 3.6 billion years ago.

Clay is a good signpost towards evidence of life because it’s usually created when rocky minerals weather away and rot after contact with water — a key ingredient for life. It is also an excellent material for storing microbial fossils.

But when Curiosity took two samples of ancient mudstone, a sedimentary rock containing clay, from patches of the dried-out lake bed, dated to the same time and place (3.5 billion years ago and just 400m apart), researchers found that one patch contained only half the expected amount of clay minerals. Instead, that patch held a greater quantity of iron oxides, the compounds that give Mars its rusty hue.

The team believes the culprit behind this geological disappearing act is brine: supersalty water that leaked into the mineral-rich clay layers and destabilized them, flushing them away and wiping patches of both the geological — and possibly even the biological — record clean.

"We used to think that once these layers of clay minerals formed at the bottom of the lake in Gale Crater, they stayed that way, preserving the moment in time they formed for billions of years," study lead author Tom Bristow, a researcher at NASA’s Ames Research Center in Mountain View, California, said in a statement. "But later brines broke down these clay minerals in some places — essentially resetting the rock record."

The rover completed its analysis by drilling into the layers of the Martian rock before using its chemistry and mineralogy instrument, known as CheMin, to investigate the samples.

The process of chemical transformation in sediments is called diagenesis, and it could have created new life beneath Mars even as it erased some of the evidence of the old life on its surface, according to the study authors. So even though old records of life may have been erased in the brine patches, the chemical conditions brought about by the influx of salty water may have enabled more life to spring up in its place, the scientists said.

"These are excellent places to look for evidence of ancient life and gauge habitability," study co-author John Grotzinger, a geology professor at the California Institute of Technology, said in the statement. "Even though diagenesis may erase the signs of life in the original lake, it creates the chemical gradients necessary to support subsurface life, so we are really excited to have discovered this."

Curiosity’s mission to Mars began nine years ago, but the rover has continued to study the Red Planet well past its initial two-year mission timeline, to establish the historic habitability of Mars for life. It is now working in collaboration with the new Perseverance Mars rover, which landed in February 2021 and has been tasked with collecting rock and soil samples for a possible return to Earth.

The research done by Curiosity has not only revealed how the Martian climate changed but also helped Perseverance determine which soil samples to collect to increase the odds of finding life.

"We’ve learned something very important: There are some parts of the Martian rock record that aren’t so good at preserving evidence of the planet’s past and possible life," co-author Ashwin Vasavada, a Curiosity project scientist at NASA’s Jet Propulsion Laboratory in California, said in the statement. "The fortunate thing is, we find both close together in Gale Crater and can use mineralogy to tell which is which."

The search for life on Mars has been given fresh impetus by a new study that could have triangulated the possible location of the six methane emissions detected by the Curiosity rover during its time in Gale crater, Live Science reported. Since all of the methane in Earth’s atmosphere comes from biological sources, scientists are thrilled to find the gas on Mars.

The researchers published their findings July 9 in the journal Science.

Source: https://www.livescience.com/mars-life-evidence-erased.html

Science: Can Sharks clone themselves?

[This is a fascinating little excerpt I came across. This is clearly not a common thing, but even so, this is definitely strange. Jan]

In a story about Sharks, it had this interesting piece:

Some captive female sharks have been known to reproduce without the aid of a male, essentially cloning themselves, Shiffman said. In 2001, a female hammerhead shark gave birth in the Henry Doorly Zoo in Nebraska without mating with a male, taking researchers by surprise. It’s an example of parthenogenesis, wherein embryos can be created with external fertilization, and has been seen in all types of animals except for mammals.

Source: https://www.livescience.com/38701-8-weird-facts-about-sharks.html

Science: Great new weird discovery: Physicists give weird new phase of matter an extra dimension

[This is fascinating. Some of this stuff is taking us well into the incredible unknown…. science fiction stuff. Jan]

Physicists have created the first ever two-dimensional supersolid — a bizarre phase of matter that behaves like both a solid and a frictionless liquid at the same time.

Supersolids are materials whose atoms are arranged into a regular, repeating, crystal structure, yet are also able to flow forever without ever losing any kinetic energy. Despite their freakish properties, which appear to violate many of the known laws of physics, physicists have long predicted them theoretically — they first appeared as a suggestion in the work of the physicist Eugene Gross as early as 1957.

Now, using lasers and super-chilled gases, physicists have finally coaxed a supersolid into a 2D structure, an advancement that could enable scientists to crack the deeper physics behind the mysterious properties of the weird matter phase.

Related: 12 stunning quantum physics experiments

Of particular interest to the researchers is how their 2D supersolids will behave when they’re spun in a circle, alongside as the tiny little whirlpools, or vortices, that will pop up inside them.

"We expect that there will be much to learn from studying rotational oscillations, for example, as well as vortices that can exist within a 2D system much more readily than in 1D," lead author Matthew Norcia, a physicist at Innsbruck University’s Institute for Quantum Optics and Quantum Information (IQOQI) in Austria, told Live Science in an email.

To create their supersolid, the team suspended a cloud of dysprosium-164 atoms inside optical tweezers before cooling the atoms down to just above zero Kelvin (minus 459.67 degrees Fahrenheit, or minus 273.15 degrees Celsius) using a technique called laser-cooling.

Firing a laser at a gas typically heats it up, but if the photons (light particles) in the laser beam are traveling in the opposite direction of the moving gas particles, they can actually cause slow and cool the gas particles. After cooling the dysprosium atoms as far as they could with the laser, the researchers loosened the "grip" of their optical tweezers, creating just enough space for the most energetic atoms to escape.

Since "warmer" particles jiggle faster than cooler ones, this technique, called evaporative cooling, left the researchers with just their super-cooled atoms; and these atoms had been transformed into a new phase of matter — a Bose-Einstein condensate: a collection of atoms that have been super-cooled to within a hair’s breadth of absolute zero.

When a gas is cooled to near zero temperature, all its atoms lose their energy, entering into the same energy states. As we can only distinguish between the otherwise identical atoms in a gas cloud by looking at their energy levels, this equalizing has a profound effect: The once disparate cloud of vibrating, jiggling, colliding atoms that make up a warmer gas then become, from a quantum mechanical point of view, perfectly identical.

This opens the door to some truly weird quantum effects. One key rule of quantum behavior, Heisenberg’s uncertainty principle, says you cannot know both a particle’s position and its momentum with absolute accuracy. Yet, now that the Bose-Einstein condensate atoms are no longer moving, all of their momentum is known. This leads to the atoms’ positions becoming so uncertain that the places they could possibly occupy grow to be larger in area than the spaces between the atoms themselves.

Instead of discrete atoms, then, the overlapping atoms in the fuzzy Bose-Einstein condensate ball act as if they are just one giant particle. This gives some Bose-Einstein condensates the property of superfluidity — allowing their particles to flow without any friction. In fact, if you were to stir a mug of a superfluid Bose-Einstein condensate, it would never stop swirling.

The researchers used dysprosium-164 (an isotope of dysprosium) because it (alongside its neighbor on the periodic table Holmium) is the most magnetic of any discovered element. This means that when the dysprosium-164 atoms were supercooled, in addition to becoming a superfluid, they also clumped together into droplets, sticking to each other like little bar magnets.

By "carefully tuning the balance between long-range magnetic interactions and short-range contact interactions between atoms," Norcia said, the team was able to make a long, one dimensional tube of droplets that also contained free-flowing atoms — a 1D supersolid. That was their previous work.

To make the leap from a 1D to a 2D supersolid, the team used a larger trap and dropped the intensity of their optical tweezer beams across two directions. This, alongside keeping enough atoms in the trap to maintain a high enough density, finally allowed them to create a zig-zag structure of droplets, similar to two offset 1D tubes sitting next to each other, a 2D supersolid.

With the task of its creation behind them, the physicists now want to use their 2D supersolid to study all of the properties that emerge from having this extra dimension. For instance, they plan to study vortices that emerge and are trapped between the droplets of the array, especially as these eddies of swirling atoms, at least in theory, can spiral forever.

This also brings researchers one step closer to the bulk, 3D, supersolids envisioned by early proposals like Gross’, and the even more alien properties they may have.

The researchers published their findings Aug. 18 in the journal Nature.

Source: https://www.livescience.com/first-2d-supersolid.html?utm_source=SmartBrief&utm_medium=email&utm_campaign=368B3745-DDE0-4A69-A2E8-62503D85375D&utm_content=C9CD1E7B-5808-4D61-9CFD-A048B7CD63FB&utm_term=23709803-d360-4259-9c73-be4ff46b5c71