Uruguay drought: Capital hit by water shortages

Oliver Pieper
DW

June 30, 2023

Montevideo is experiencing its worst drought in over 70 years. The situation is being worsened by locals hoarding water supplies.

Mariana Meerhoff wants to see more funding for the environmental protection ministry and others

Uruguay was the first country in the world to enshrine the right to clean drinking water in its constitution in 2004. Now, it seems, it's reliant on divine intervention to fulfill this pledge. Montevideo archbishop Daniel Sturla recently tweeted: "Our God, we pray that You grant us the necessary rain."



While many in Uruguay's capital Montevideo, a metropolis of 1.3 million people, thanked the Church for its efforts, others said they doubted that God even follows Twitter.

In any case, only a few raindrops fell from the sky in recent days because the La Nina weather phenomenon is increasingly turning Uruguay, and the capital especially, into a desert.
Empty reservoir

"We had a two-year drought, which was superseded by an extreme drought in the last few months," biologist and environmental expert Mariana Meerhoff told DW. "It is an absolutely exceptional situation for Uruguay."

She says the country is seeing a record drop in precipitation. "We've never had so little rain," Meerhoff says. "The situation in Montevideo is so dramatic because, of course, a lot of people depend on drinking water."

Montevideo and the greater metropolitan area, where more than half of Uruguay's population live, is slowly running out of precious drinking water. Its most important water source, the Paso Severino reservoir located north of Montevideo, is nearly completely empty and currently only holds 3% of its normal capacity.

Uruguay's President Luis Lacalle Pou has declared a water emergency for Montevideo and the wider metropolitan area. For the time being, bottled water is now exempt from taxes. Uruguay's poor, who are especially hard-hit in these tough times, will receive two liters of water (about half a gallon)sai per day free of charge.

Six-liter canisters of drinking water sold in supermarkets have become highly sought-after and are also being carted in from other parts of the country. Three times more water bottles are being sold in Uruguay than usual. This is partly due to hoarding, not dissimilar to the early days of the pandemic around the globe.

Some people in Uruguay blame President Luis Lacalle Pou for inaction

Image: Agustin Marcarian/REUTERS

Politicians slow to act

"Politicians have reacted far too late to this situation, even though the scientific community has been warning of Uruguay's drinking water problem for almost three decades," says Meerhoff. "They refuse to acknowledge how dramatic the drinking water situation really is." Meerhoff says "water crises like this will increase in the future and become even more severe."

In Montevideo, which once boasted some of the best municipal water in South America, not even 50% of households open their taps anymore, surveys show. The reason is that anyone who takes a sip will likely feel like they are drinking water from the Atlantic Ocean. The pitiful remains from the reservoir have been mixed with water from the pesticide-contaminated River Plate. River and seawater mix in the estuary of the Rio Parana and Rio Uruguay streams, leading to an increased chlorine and salt content in Montevideo's municipal water, far exceeding World Health Organization thresholds.

Uruguay's water emergency has therefore escalated into a political crisis, sparking street protests. Environmental protection group Redes - Amigos de la Tierra blames the dire situation on "plundering." It says that cellulose factories, rice-growing companies and soy farmers consume vast amounts of water without having to pay a single peso.

Montevideo protesters took to the streets on May 31 demanding the government take urgent steps to tackle the water shortage

Image: Matilde Campodonico/dpa/AP/picture alliance

Agriculture and industry to blame?

"Almost 80% of our freshwater goes to the agricultural and forestry sector, so we can certainly say water resource exploitation is very high in Uruguay," says Meerhoff. "Because so much water is used in industry, the amount for water for personal use and nature is obviously very limited."

Montevideo hospitals and schools now receive drinking water from two wells in the city center, which were rapidly built because of the water shortage. Another reservoir near Montevideo has been in the works for six months. And the repair of the city's old leaky pipes, which often lose a significant amount of water, should soon be on politicians' to-do list.

How climate change is intensifying drought  04:00

Unfortunately, many of these measures are only a drop in the ocean. What Uruguay needs – along with many countries and cities around the world – is water long-term strategy. "What is happening here in Montevideo can happen in any city in the world," says environmental expert Meerhoff. "It has happened before a few years ago in Cape Town, South Africa, and Curitiba, Brazil when extreme drought left people without drinking water — with climate change, such scenarios are becoming more and more likely around the world."

Target of 1.5°C global warning threshold going out of reach amid record land & sea temperatures

Though mean temperatures had temporarily breached the 1.5 degrees Celsius threshold before, this was the first time they had done so in the northern hemisphere summer that starts on June 1. Sea temperatures also broke April and May records.

Reuters

Singapore,UPDATED: Jul 1, 2023 

In India, one of the most climate vulnerable regions, deaths were reported to have spiked as a result of sustained high temperatures. (Photo: Vani Gupta/India Today)

By Reuters: The target of keeping long-term global warming within 1.5 degrees Celsius is moving out of reach, climate experts say, with nations failing to set more ambitious goals despite months of record-breaking heat on land and sea.

As envoys gathered in Bonn in early June to prepare for this year's annual climate talks in November, average global surface air temperatures were more than 1.5 degrees Celsius above pre-industrial levels for several days, the EU-funded Copernicus Climate Change Service (C3S) said.

Though mean temperatures had temporarily breached the 1.5 degrees Celsius threshold before, this was the first time they had done so in the northern hemisphere summer that starts on June 1. Sea temperatures also broke April and May records.

"We've run out of time because change takes time," said Sarah Perkins-Kirkpatrick, a climatologist at Australia's University of New South Wales.

As climate envoys from the two biggest greenhouse gas emitters prepare to meet next month, temperatures broke June records in the Chinese capital Beijing, and extreme heatwaves have hit the United States.

Parts of North America were some 10 degrees Celsius above the seasonal average this month, and smoke from forest fires blanketed Canada and the US East Coast in hazardous haze, with carbon emissions estimated at a record 160 million metric tons.

In India, one of the most climate-vulnerable regions, deaths were reported to have spiked as a result of sustained high temperatures, and extreme heat has been recorded in Spain, Iran and Vietnam, raising fears that last year's deadly summer could become routine.

Countries agreed in Paris in 2015 to try to keep long-term average temperature rises within 1.5 degrees Celsius, but there is now a 66 per cent likelihood the annual mean will cross the 1.5 degrees Celsius threshold for at least one whole year between now and 2027, the World Meteorological Organisation predicted in May.

'QUADRUPLE WHAMMY'

High land temperatures have been matched by those on the sea, with warming intensified by an El Nino event and other factors.

Global average sea surface temperatures hit 21 degrees Celsius in late March and have remained at record levels for the time of year throughout April and May. Australia's weather agency warned that Pacific and Indian Ocean sea temperatures could be 3 degrees Celsius warmer than normal by October.

Global warming is the major factor, said Piers Forster, professor of climate physics at the University of Leeds, but El Nino, the decline in Saharan dust blowing over the ocean and the use of low-sulphur shipping fuels were also to blame.

"So in all, oceans are being hit by a quadruple whammy," he said. "It's a sign of things to come."

ALSO READ | Relentless heatwave scorches US South, air quality deteriorates over Midwest

Thousands of dead fish have been washing up on Texan beaches and heat-induced algal blooms have also been blamed for killing sea lions and dolphins in California.

Warmer seas could also mean less wind and rain, creating a vicious circle that leads to even more heat, said Annalisa Bracco, a climatologist at the Georgia Institute of Technology.

Though this year's high sea temperatures are caused by a "perfect combination" of circumstances, the ecological impact could endure, she said.

"The ocean is going to have a very slow response as it accumulates (heat) slowly but also keeps it for very long."

THE ROAD TO DUBAI

Climate experts say the extent and frequency of extreme weather are increasing, and this year has also seen punishing droughts across the world, as well as a rare and deadly cyclone in Africa.

The Worldwide Fund for Nature, however, warned of a "worrying lack of momentum" during climate talks in Bonn this month, with little progress made on key issues like fossil fuels and finance ahead of November's COP28 climate talks in Dubai.

"It was very detached from what was going on outside of the building in Bonn - I was very disappointed by that," said Li Shuo, Greenpeace's senior climate adviser in Beijing.

"We are really getting to the moment of truth ... I am hoping that the sheer reality will help us change people's moves and change politics."

ALSO READ | Beijing upgrades hot weather alert to highest level as heat wave shatters records

Talks between the United States and China could resume next week with US climate envoy John Kerry set to visit Beijing, though few expect it to add momentum to climate negotiations.

"This is more of a trust-building exercise," Li said. "I don't think either side will be able to push the other side to say much more than they are willing to do -- the politics won't allow that."

--- ENDS ---

Posted By:

Prateek Chakraborty

Published On:

Jul 1, 2023

Mysterious 'zombie planet' Halla seems to have survived the explosive death of its star. How?

By Ben Turner

 published 1 day ago

The Jupiter-sized exoplanet Halla has somehow survived the death of its star, and astronomers aren't sure how.

An artist's illustration of Halla surviving a potential cataclysmic merger between the two stars in its binary system. (Image credit: W. M. Keck Observatory/Adam Makarenko)

Astronomers have discovered a Jupiter-size planet that "shouldn't exist" after the sudden and violent expansion of its host star.

The gas giant 8 Ursae Minoris b — also known as Halla — is a "hot Jupiter" planet located 520 light-years from Earth. The enormous world seemingly faced certain destruction after its host star, Baekdu, ballooned to thousands of times its original size to devour any planets in its orbit.

And yet, mysteriously and miraculously, Halla survived. Astronomers published their findings June 28 in the journal Nature.

Related: A 'captured' alien planet may be hiding at the edge of our solar system — and it's not 'Planet X'

"Engulfment by a star normally has catastrophic consequences for close orbiting planets," study co-author Daniel Huber, an astronomer and research fellow at the Sydney Institute for Astronomy in Australia, said in a statement. "When we realized that Halla had managed to survive in the immediate vicinity of its giant star, it was a complete surprise."

As Baekdu exhausted its supply of hydrogen fuel, the star would have expanded immensely, inflating up to 1.5 times Halla's orbital distance, the researchers added. Halla should have been completely engulfed — and incinerated — before the dying Baekdu shrank back to its current size. However, that doesn't seem to have happened.

Halla was first discovered by Korean astronomers in 2015, using a technique known as the radial velocity method, which searches for the tugs of hidden planets in the wobbling of distant stars. Yet Halla presented a mystery: It was orbiting the star Baekdu (which has a radius that's nearly 11 times that of the sun and a mass 1.6 times our star's), which had already transformed into a red giant.

For most of their lives, stars burn by fusing hydrogen atoms into helium. Once they have exhausted their hydrogen fuel, however, they begin fusing helium, leading to a massive increase in energy output that causes them to swell to hundreds, or even thousands, of times their original size. As the stars expand, they gobble up their inner planets, transforming into huge stars called red giants.

To establish that Halla was one of Baekdu's original planets and not a cosmic interloper, the researchers made observations using the Keck Observatory and the Canada-France-Hawaii Telescope in 2021 and 2022, which confirmed that the planet's 93-day, near-circular orbit had been stable for more than a decade.

Still, the astronomers think it's almost impossible that Halla was ever touched by its star, which lies about half the distance from the planet as Earth does from the sun.

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"We just don't think Halla could have survived being absorbed by an expanding red giant star," Huber said.

Instead, the researchers have narrowed the possibilities to two options: Either Halla was born after Baekdu transformed into a red giant, or Baekdu was once one of two stars in a binary system that later merged, preventing either from expanding sufficiently to consume Halla.

"The system was more likely similar to the famous fictional planet Tatooine from Star Wars, which orbits two suns," study co-author Tim Bedding, an astronomy professor at the University of Sydney, said in the statement. "If the Baekdu system originally consisted of two stars, their merger could have prevented any one of them from expanding sufficiently to engulf the planet."

Euclid space telescope blasts off to explore dark matter

SpaceX’s Falcon 9 rocket has launched the European Space Agency’s Euclid telescope from Florida. The extraordinary telescope is set to unravel the "dark" or unknown mysteries of the universe.

The Euclid's primary goal is to study dark matter and dark energy

Image: Malcolm Denemark/Florida Today/USA TODAY Network/IMAGO

The European Space Agency’s Euclid space telescope lifted off aboard a SpaceX rocket from Florida on Saturday.

The telescope, which successfully separated from the rocket about an hour after the launch, is set to explore the "dark" or unknown realms of the universe.

Flight controllers in Germany declared success less than an hour into the flight, applauding and shouting "Yes" after they received a signal from the telescope after it separated from the rocket.

"I'm so thrilled, I'm so excited to see now this mission up in space, knowing it is on its way," the European Space Agecy Director General Josef Aschbacher said from the launch site in Florida.

The Euclid telescope now sets off on a monthlong journey to its destination, known as the second Lagrange point (L2) of the solar orbit, where gravity from the sun and Earth balance the orbital motion of a satellite.



There are five so-called "Lagrange Points," according to NASA. L2 is nearly 1 million miles (1.6 million kilometers) away from Earth.

From L2, the telescope will survey galaxies as far away as 10 billion light years from Earth across an immense expanse of the sky beyond our own Milky Way galaxy.

EUCLID probe aims to discover secrets of universe  04:09

The spacecraft, which weighs 2 tons, is also equipped with instruments designed to measure the intensity and spectrums of infrared light from those galaxies in a way that will precisely determine their distances.

 
Why exploring the "dark" side of the universe matters

The telescope is set to produce the largest and the most accurate map of the universe so far, including the distribution of galaxies spanning the last 10 billion years of cosmic time, explained Elsa Montagnon, the head of Mission Operations Division at NASA.

That gives scientists the ability to comprehensively study the evolution and composition of the universe, Montagnon added during a live broadcast of the launch.

The Euclid mission is set to unravel the mysteries of the dark energy, which together with dark matter comprises 95% of the cosmos, Montagnon said.

Visible stars and galaxies make up less than 5% of the universe, and the Euclid will allow scientists to study the universe as it is.

What to know about dark energy and dark matter

There are two highly important instruments within the telescope that will take images to allow scientists to study the two foundational components of the universe.

One is dark matter, which is an invisible form of matter that makes up most of the universe's mass and creates its underlying structure. Dark matter's gravity drives normal matter (gas and dust) to collect and build up into stars and galaxies.

The other is dark energy, an equally enigmatic force believed to explain the universe's expansion.

Other than that, dark energy is a complete mystery to scientists.

Roughly 68% of the universe is dark energy, while dark matter makes up about 27%. The rest, or everything else ever observed on Earth, adds up to less than 5% of the universe.

rm/wd (AFP, Reuters)

SEE 

BEFORE DARK MATTER OR DARK ENERGY THERE WAS ETHER  

LA REVUE GAUCHE - Left Comment: Search results for AETHYR 

LA REVUE GAUCHE - Left Comment: Search results for DARK MATTER 

LA REVUE GAUCHE - Left Comment: Search results for DARK ENERGY

Europe’s space telescope to target universe’s dark mysteries

By AFP
Published July 1, 2023

The Euclid spacecraft, pictured before being sent to Florida, will blast off on a mission to find out more about the 'dark universe' - Copyright AFP/File Valery HACHE

Gianrigo Marletta, with Lucie Aubourg in Washington

Europe’s Euclid space telescope is scheduled to blast off Saturday on the first-ever mission aiming to shed light on two of the universe’s greatest mysteries: dark energy and dark matter.

The launch is planned from Cape Canaveral in Florida at 11:12 am local time (1512 GMT) on a Falcon 9 rocket of the US company SpaceX.

The European Space Agency was forced to turn to billionaire Elon Musk’s firm to launch the mission after Russia pulled its Soyuz rockets in response to sanctions over the war in Ukraine.

After a month-long journey through space, Euclid will join its fellow space telescope James Webb at a stable hovering spot around 1.5 million kilometers (more than 930,000 miles) from Earth called the second Lagrange Point.

From there, Euclid will chart the largest-ever map of the universe, encompassing up to two billion galaxies across more than a third of the sky.

By capturing light that has taken 10 billion years to reach Earth’s vicinity, the map will also offer a new view of the 13.8-billion-year-old universe’s history.

Scientists hope to use this information to address what the Euclid project manager Giuseppe Racca calls a “cosmic embarrassment”: that 95 percent of the universe remains unknown to humanity.

Around 70 percent is thought to be dark energy, the name given to the unknown force that is causing the universe to expand at an accelerated rate.

And 25 percent is dark matter, thought to bind the universe together and make up around 80 percent of its mass.

“Ever since we could see stars we’ve wondered, is the universe infinite? What is it made out of? How does it work?” NASA Euclid project scientist Michael Seiffert told AFP.

“It’s just absolutely amazing that we can take data and actually start to make even a little bit of progress on some of these questions.”

– ‘Dark detective’ –

Euclid consortium member Guadalupe Canas told a press conference that the two-tonne space telescope was a “dark detective” which can reveal more about both elements.

Euclid, which is 4.7 meters (15 feet) tall and 3.5 meters wide, will use two scientific instruments to map the sky.

Its visible light camera will let it measure the shape of galaxies, while its near infrared spectrometer and photometer will allow it to measure how far away they are.

So how will Euclid try to spot things that cannot be seen? By searching for their absence.

The light coming from billions of light years away is slightly distorted by the mass of visible and dark matter along the way, a phenomenon known as weak gravitational lensing.

“By subtracting the visible matter, we can calculate the presence of the dark matter which is in between,” Racca told AFP.

While this may not reveal the true nature of dark matter, scientists hope it will throw up new clues that will help track it down in the future.

For dark energy, French astrophysicist David Elbaz compared the expansion of the universe to blowing up a balloon with lines drawn on it.

By “seeing how fast it inflates,” scientists hope to measure the breath — or dark energy — making it expand.

– ‘Goldmine’ –

A major difference between Euclid and other space telescopes is its wide field of view, which takes in an area equivalent to two full moons.

Project scientist Rene Laureijs said that this wider view means Euclid will be able to “surf the sky and find exotic objects” like black holes that the Webb telescope can then investigate in greater detail.

Beyond dark energy and matter, Euclid’s map of the universe is expected to be a “goldmine for the whole field of astronomy,” said Yannick Mellier, head of the Euclid consortium.

Scientists hope Euclid’s data will help them learn more about the evolution of galaxies, black holes and more.

The first images are expected once scientific operations start in October, with major data releases planned for 2025, 2027 and 2030.

The 1.4 billion euro ($1.5 billion) mission is intended to run until 2029, but could last a little longer if all goes well.

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The Euclid telescope: On the trail of dark energy and matter

Esteban Pardo

DW
June 29, 2023

On July 1 a new telescope will begin mapping the distant universe in greater detail than ever seen before, improving our understanding of dark matter and dark energy.

The Euclid space telescope has optical and near-infrared detectors and will map the distribution and evolution of distant galaxies and dark matter.

You've probably heard of dark matter and dark energy, right? They sound like something straight out of a Star Wars movie. Terms like these can sound so foreign to us that we just don't bother thinking about them. That's what often happens in science. Getting our heads around some of its concepts can be very challenging — yes, I'm looking at you, quantum mechanics.

Unraveling these mysteries is one of the main goals of the new Euclid space telescope, which is set for launch on July 1 on a SpaceX Falcon 9 rocket in Cape Canaveral, Florida, USA. Its mission is to deepen our understanding of dark matter and dark energy. Euclid won't be able to answer the many questions that remain about the dark universe, but it will take a big step on the path to investigating two of its most intriguing components.

Ok, cool, but why should we care? Well, because ultimately Euclid's task is to explore some of the most profound and fundamental questions in cosmic history: How did the universe originate and what is it made of? What are the fundamental physical laws of the universe? Just take a second to pause, look up into the stars, and ask yourself these questions. Let the mind wander.
The building blocks of the universe

"Both dark matter in particular, but also dark energy, ultimately our existence traces back to those," Hans-Walter Rix, astronomer and director of the Max Planck Institute for Astronomy, in Heidelberg, Germany, told DW.

Dark matter and dark energy provided the right conditions for enough material to come together and form the stars, planets, galaxies, life, you and me. So understanding them is a step closer to understanding where we come from.

This is what makes the mission such an historic one. The Euclid telescope is led by the European Space Agency (ESA) with contributions from NASA. It took more than ten years of development, €1.4 billion and more than 3,500 scientists from 21 countries.

Euclid was originally planned to launch from a Russian Soyuz rocket in 2022, but Russia's invasion of Ukraine called for a change of plans.

This simulation from 2014 shows the distribution of galaxies in the universe and how a kind of web pattern emerges on a very large scale

.Image: Illustris Collaboration/AP Photo/picture alliance

The distant universe in unprecedented detail

Good news for the James Webb Space Telescope — it's getting company. Euclid, like the Webb, will also orbit the second Lagrange point (L2), 1.5 million kilometers (about 930,000 miles) from Earth. This point is a special place in space that moves in synchrony with the Earth around the sun.

The questions Euclid is tasked with addressing are pretty ambitious ones. The primary goal is to create a map. "It is the biggest and most accurate map of the universe, what we are basically aiming to do, that has never been done before," Guadalupe Cañas Herrera, a cosmologist working on the Euclid mission at ESA, told DW.

It takes its name from the Greek mathematician Euclid of Alexandria, who lived in the 3rd century BC and is known as the father of geometry — and the terror of high school students. The mission is named in his honor because better understanding of how everything is distributed in the universe tells us a lot about its geometry.

To make the map, Euclid is going to look at and measure billions of galaxies — yes, that's a thousand million — with extreme precision over a span of at least six years. Euclid is equipped with a visible light sensor and a near-infrared instrument capable of accurately measuring the distance of these galaxies.

"We are aiming to do something really challenging or something that is really ambitious, which is mapping a third of the full sky," said Cañas.
Euclid vs. the James Webb

One third of the sky is huge. Just take a look at the deep field image from the James Webb, down here.

This was the Webb's first picture. It pointed at a galaxy cluster in the center of the image that is so massive that it causes light from background objects to bend, like looking at space through a glass of water. That's why some objects appear distorted or stretched.

Image: NASA, ESA, CSA, STScI, Webb ERO Production Team

That was just a portion of the sky the size of a grain of sand on your fingertip on a stretched arm, so imagine how many stars and galaxies there are in a third of the whole sky, — and how many planets.

They are both space telescopes, but they have different purposes. Euclid's mirror is 1.2 m in diameter, compared to the Webb's huge 6.5 m. But the James Webb is like a precise pencil that sketches fine details, it looks at a very small portion of the sky with amazing detail. Euclid is more like a brush that can cover big patches of sky quickly.

But don't be fooled by Euclid's size, "Euclid will actually take a very high-resolution picture of the sky that will deliver gorgeous, gorgeous pictures," added Rix.

How the shape of the universe has changed over time

Euclid will be glimpsing into the past. That's because light takes a while to travel through the immensity of space. For example, it takes light eight minutes to travel from the sun to us. So, at larger distances, the farther we look, the earlier we see into our universe.

And these galaxies can be very far away, with their light taking up to 10 billion years to reach us. For reference, the age of the universe is around 13.8 billion years.

The goal here is to have the best understanding to date of where galaxies are in the distant universe up to 10 billion light-years away, but also how the shape of the distant universe has evolved over time.

But to better understand how this can help answer the previously mentioned questions and how all of these is related to dark matter and dark energy, we first need to talk about the dark universe.

The dark universe

Everything we know and see — bacteria, plants, animals, stars, planets, galaxies — is made of atoms that you can pinpoint in the periodic table. Astronomers refer to this as baryonic matter, in case you want to dazzle your cosmologist cousin.

But this visible matter is just a fraction of what the universe is made of — just 5%. The rest is dark matter and dark energy.

We might not know what they are, but there are many different lines of evidence that tell us that for sure they are there.

Dark matter seems to be keeping galaxies together, making the stars inside orbit faster than we would expect them to, and preventing galaxies from falling apart. It doesn't emit or absorb light, but we can also tell it's there by how seemingly empty regions of space bend the light of objects behind it — what's called gravitational lensing. And there's a lot of dark matter, around five times more than ordinary matter.

The idea of dark energy was first mooted in the 1990s, when scientists discovered that, contrary to what they thought, everything in the universe, on a larger scale, is moving apart from everything else at an accelerated rate. Just as your speed increases every second when you press down on the gas pedal, a very distant galaxy is moving away from us faster every second. Dark energy is what we call the unknown driving agent of this accelerating expansion.

A good analogy, and something you can try at home, is to grab a balloon that's just slightly inflated, draw a few dots with a marker on it and then start blowing it up. You'll see every dot getting further apart from all the other dots. That's exactly like what happens in our universe.

We don't experience this expansion in our daily life because our galaxy, for example, is tightly bound by gravity — mostly from dark matter.

This optical illusion happens due to gravitational lensing. There's so much mass on that bright red galaxy at the center that its gravity causes the light of a background blue galaxy to bend, what makes it appear distorted. It is possible to determine the amount of mass needed to have such a distortion and compare it with the mass we can see, if it doesn't add up, it's because there's dark matter too.

Image: ESA/Hubble & NASA

Euclid, dark matter and dark energy

"You are not just mapping where all the stuff you can see is, but we will also map where all the stuff we can't see is," Becky Smethurst, a Royal Astronomical Society Research Fellow at the University of Oxford, told DW.

Euclid will not only map the visible, "ordinary" matter, but also dark matter in the universe. A more detailed map of where dark matter is and how it is distributed can be a huge help in trying to better understand what dark matter is.

About that gravitational lensing mentioned earlier. This occurs when a gravitational field distorts light just like a lens, or a glass of water. The light of very far away galaxies gets distorted — often in a sausage shape. And depending on the level of distortion, gravitational lensing can indirectly tell us how much dark matter there is.

Well, Euclid is going to exploit the phenomenon to look into billions of distorted galaxies and infer the amount and distribution of dark matter there is, effectively creating a gigantic 3D map.

Mapping all these millions of galaxies requires very precise measurements of how distant they are. This is measured by the red shift. The expanding universe stretches light waves, and that can be measured. This way, Euclid is going to provide the most precise measurements ever taken of how the larger cosmic structures have changed over time, effectively tracing the effects of dark energy, which ultimately will tell us much more about what dark energy is and what it is not.