Connect with us

The Conversation

Chang’e 6 brought rocks from the far side of the Moon back to Earth − a planetary scientist explains what this sample could hold

Published

on

theconversation.com – Jeffrey Gillis-Davis, Research Professor of Physics, Arts & Sciences at Washington University in St. Louis – 2024-08-06 07:45:05

The Chang’e 6 minirover Weibo took this image of the lander by autonomously driving away and photographing it.
CNSA

Jeffrey Gillis-Davis, Arts & Sciences at Washington University in St. Louis

China achieved a historic feat by bringing back the first-ever sample from the lunar far side in June 2024. It’s moon lander, Chang’e 6, used a robotic scoop and drill to collect approximately 5 pounds (2 kilograms) of rocks and soil. These samples came back to Earth on June 25, 2024.

Chang’e 6 built off the accomplishments of two previous Chinese missions: Chang’e 4, which soft-landed on the far side of the Moon and used a rover to explore the surface, and Chang’e 5, which returned samples from the Moon’s near side.

Scientists expect the Chang’e 6 samples to deliver not only key geologic knowledge about the Moon but also improve their understanding of Earth and the solar system’s early history.

Chang’e 6 returned samples to Earth on June 25, 2024.

Lunar scientists like myself have been fascinated with the far side of the Moon since the Soviet Union’s Luna 3 mission in 1959, which revealed that the Moon’s far side looks very different from its near side.

The far side of the Moon

Because the same side of the Moon always faces toward Earth, you can see the far side only with spacecraft. The far side is not permanently dark – it alternates between two weeks of daylight and two weeks of night, just like any location on the Moon.

Images taken by spacecraft show that about a third of the Moon’s near-side surface is made up of dark, smooth plains, while only about 1% of the far side has these plains.

These dark plains were once volcanic lava flows, similar to those found on Earth in Hawaii, eastern Washington and India.

Images taken from lunar orbit tell researchers that these plains once had volcanic vents, cones, domes, collapsed pits and channels.

Only the Chang’e 4 and Chang’e 6 missions have landed on the lunar far side, while 25 spacecraft have successfully soft-landed on the near side. A landed mission on the far side is more difficult because mission control cannot directly see or talk with the spacecraft. So what’s needed is a second spacecraft to relay information between the lander and Earth. China used its orbiting satellite Queqiao-2, which was launched in March 2024.

Chang’e 6’s touchdown

On June 6, 2024, Chang’e 6 landed within the colossal South Pole-Aitken basin, which is about 1,550 miles (2,500 km) wide and 5 miles (8 km) deep. It’s the solar system’s largest impact structure: a bowl-shaped feature formed when an asteroid collides with a body, causing an enormous explosion.

A topographic image of the Moon, with a large region colored blue towards the south pole indicating the South Pole-Aitkin basin.
The South Pole-Aitkin basin, shown as blue on this topographic map, is the largest basin on the Moon and the site of the Chang’e 6 mission. The Apollo basin is the blue bull’s-eye featured in the upper right corner of the larger basin.
NASA/GSFC/University of Arizona

Superimposed on top of South Pole-Aitkin is a slightly younger and much smaller impact structure called the Apollo basin, about 308 miles (492 km) in diameter.

Impact basins expose the Moon’s deep interior like a drill core. For instance, the impact that created the South Pole-Aitkin basin may have removed part of the Moon’s crust, exposing materials deep inside the Moon – up to 62 miles (100 km) down. The subsequent Apollo impact would have then removed even more material. So, the returned samples will likely contain some rocks that are different from those in the current sample collection.

Chang’e 6 landed here on some of the sparse, far-side volcanic deposits. Analyzing the composition of the volcanic rocks Chang’e 6 brought back might help researchers figure out why the near side has so many more volcanic deposits. Scientists will also be able to compare the ages of these far-side rocks with rocks from volcanic eruptions on the near side that took place about 3.9 to 3.2 billion years ago.

Measuring the rocks’ actual ages will help scientists refine other methods, such as crater counting, that are used to estimate the age of surface formations on planets.

Since planet surfaces accumulate more craters the longer they’re around, researchers can estimate a planetary surface’s age by comparing the number of craters they can count to those generated by a simulated model. But crater counting isn’t very accurate – having actual rock samples can help researchers figure out how to improve these methods.

Uncovering secrets from the Moon’s molten past

Researchers theorize that the Moon, along with some rocky planets, used to be almost completely molten. So for a brief period of time early in its history, the Moon was just lava with little or no solid rock.

Chang’e 6’s landing site could contain materials from the Moon’s mantle – the layer beneath its crust. These samples could help scientists understand how the Moon evolved from a magma ocean to having geologic layers – a solidified crust, mantle and core.

Data from these samples could also provide clues about Earth’s evolution in the last stages of planetary formation. Scientists predict that about 4 billion years ago, lots of asteroids and comets rained down on rocky planets like Earth. We call this period the “lunar cataclysm” period. Studying certain rocks from crater impacts on the Moon could help scientists learn more about this era.

Since the South Pole-Aitkin basin is the oldest well-preserved structure on the Moon, it could hold evidence about whether the number of basin-forming impacts occurred over a longer period of time, like 500 million years, or a shorter period, like 200 million years. Knowing the timescale would help gauge the intensity of impacts during the solar system’s formation.

A scientific gift from the far side

Extraterrestrial materials – such as samples from the Moon, Mars, asteroids and comets – are gifts that keep on giving.

Scientists will curate and maintain these samples in laboratories to keep them pristine. This process will distribute some of the precious samples for analyses with state-of-the-art equipment. The rest will be stored for future generations of scientists to explore new questions that emerge decades from now.

Science makes the most progress when scientists share ideas, data and samples. At the end of 2023, the China National Space Administration made the samples from Chang’e 5 available to a set of international researchers. I expect to see a similar sample-sharing program for the Chang’e 6 samples.

This sharing, however, doesn’t go both ways. NASA cannot directly share the samples they curate with Chinese researchers because of the Wolf Amendment, which bars NASA from using funds to collaborate with China on any programs.

China’s future lunar exploration plans include the Chang’e 7 and 8 missions, planned for 2026 and 2028, respectively. These missions will land at the south pole to search for water ice, carbon dioxide ice – also known as dry ice – and methane in an ice form. NASA’s recently canceled VIPER rover had similar goals. These missions will help China figure out where to put its International Lunar Research Station, which is planned for 2030.The Conversation

Jeffrey Gillis-Davis, Research Professor of Physics, Arts & Sciences at Washington University in St. Louis

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Read More

The post Chang’e 6 brought rocks from the far side of the Moon back to Earth − a planetary scientist explains what this sample could hold appeared first on theconversation.com

The Conversation

Rents rise faster after disasters, but a federal program can help restrain excesses

Published

on

theconversation.com – Anthony W. Orlando, Assistant Professor of Finance, Real Estate and Law, California State Polytechnic University, Pomona – 2025-01-14 13:02:00

Two people embrace on Jan. 9, 2025, in Altadena, Calif., amid property destroyed by the Eaton Fire.
Justin Sullivan/Getty Images

Anthony W. Orlando, California State Polytechnic University, Pomona

The wildfires raging across Los Angeles are setting the scene for a real estate nightmare.

Thousands of homes and other structures are destroyed and hundreds of thousands of residents have been evacuated at various times. Many will not return for months, if ever. Homeless in an instant, they are now flooding the housing market, desperately seeking shelter.

The Los Angeles housing market is poorly equipped for this crisis. It is already one of the nation’s most expensive markets to buy or rent a place to live, largely due to a significant and growing shortage of affordable housing. That shortage will become only more dire with the destruction of so many fire-ravaged buildings.

For the past two years, I have been studying the effects of natural disasters like this one on rental housing markets. As a professor of real estate, I have analyzed the question from a distance, sifting through data.

This time, however, as a resident of Pasadena, I have seen the carnage up close. I watched the Eaton Fire spread across the mountains from my back porch. I helped friends evacuate before their neighborhood was consumed in flames. Now, they’re sitting at my dining table as they process what they’ve lost and search for a new place to live.

Unfortunately, from my research, I have no doubts about what comes next.

Why disasters drive up rents

Scarcity is the enemy of affordability. This is one of the central tenets of economics. When too many people chase too few goods, prices rise.

So, you might expect that a natural disaster, which destroys housing and inundates the remaining units with new renters, would drive up rents, at least in the short run.

That is exactly what my research has found – but it’s not just the short run.

Two years ago, I worked with a team of researchers to prepare a report for the Brookings Institution, where we compiled a database of natural disasters across a variety of major markets throughout the country from 2000 to 2020. We measured the change in rents in places such as Atlanta, Detroit, Miami and San Francisco that landlords were asking for apartments in disaster-impacted neighborhoods. We then compared those cities with similar neighborhoods that weren’t impacted by the disasters.

We found that natural disasters increased rents during those two decades by 4% to 6%. That means rents were at least 4% higher than they would have been in the absence of the disaster.

These rent hikes were especially clear and pernicious after wildfires in California.

These weren’t just short-term effects. It took 18 months for the full effects to be felt in the market, and they never fully went away. Even four years after the disaster, renters were still paying 2% to 3% more than they would have been without the disaster.

In short, we found that disasters permanently change rental housing markets. They eliminate older, affordable housing, allowing developers to build newer, higher-end and even luxury housing in its place. Those changes drive up insurance costs, and the disasters motivate cities to adopt stricter building codes that in turn add to construction costs for the sake of weathering future disasters better.

How much rents increase, however, depends on how communities and the authorities respond to the disaster.

A burnt-out area following a big fire.
Burned homes are seen from above near the Los Angeles neighborhood of Pacific Palisades on Jan. 9, 2025, after massive fires engulfed whole neighborhoods and displaced thousands of people.
Josh Edelson AFP via Getty Images

Federal aid can slow the growth of rents

We found that rents did not grow as fast when the government stepped in to help.

Specifically, we investigated markets where Congress had used the Community Development Block Grant Disaster Recovery – CDBG-DR – program, providing grants through the Department of Housing and Urban Development. This federal funding typically comes with strings attached and “rental requirements” often mandating that a significant portion of the money be used to build affordable housing.

At least one of these disaster relief grants was issued every year from 2003 to 2020. In some years, Congress allocated as many as 27 different grants across the country to different disaster-impacted areas.

In these markets, we found that rents still rose after disasters – but at a significantly slower pace than in the markets where Congress didn’t send these disaster relief funds.

We dug deeper into several case studies in 2024 to understand why the CDBG-DR program is associated with lower rent hikes over the long run. In this new study, we found that housing markets that benefited from these disaster relief grants were able to build more rental units, easing the housing shortage. They improved affordability by tackling the scarcity problem directly.

Rental units were the key to solving the rent crisis. These cities, where affordability was better post-disaster, didn’t build more single-family homes than the other cities. They built more apartment units.

In these markets, these disaster relief grants saved the average renter between $780 and $1,080 in annual housing costs in 2023.

We believe that this finding shows why it is important not only to rebuild the houses destroyed in disasters like the Los Angeles fires but also to create new rental opportunities in all kinds of housing.

Hope in the aftermath

Here in Los Angeles, the clock is already ticking.

News reports are mounting of landlords raising rents to eye-popping levels.

Fortunately, there are government policies and programs that can help Angelenos find shelter today and that may help the Los Angeles housing market not get even less affordable tomorrow.The Conversation

Anthony W. Orlando, Assistant Professor of Finance, Real Estate and Law, California State Polytechnic University, Pomona

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Read More

The post Rents rise faster after disasters, but a federal program can help restrain excesses appeared first on theconversation.com

Continue Reading

The Conversation

How the CIA director helps the US navigate a world of spies, threats and geopolitical turbulence

Published

on

theconversation.com – Matthew Clary, Senior Lecturer in Political Science, Auburn University – 2025-01-14 12:44:00

The CIA is the U.S.’s premiere spy agency.
Mark Wilson/Getty Images

Matthew Clary, Auburn University

Today, the United States is navigating an increasingly unsettled world. The positions advising the president on national security are as important as ever. One such position, the director of the Central Intelligence Agency, is key to providing the president and Cabinet with timely intelligence and analysis.

So, what is the job of director of the CIA? What role does the director play in U.S. national security? How has the position changed over time?

The CIA’s role in national security

The CIA director leads the government agency responsible for conducting espionage and covert action. The CIA director is a Cabinet level position but reports to the director of national intelligence.

The CIA was established by the National Security Act of 1947 as America’s premiere civilian-led foreign intelligence agency. The agency carries out espionage and covert action exclusively outside the U.S.

The CIA is organized into five directorates – analysis, operations, science and technology, digital innovation, and support – and 11 regional and topical mission centers. The number of CIA employees is classified.

Espionage activities include the use of spies tasked with collecting useful information from influential people in countries around the world. This information, referred to as human intelligence, often provides depth and context about threats posed to the U.S.

In addition to collecting intelligence, the CIA analyzes and interprets it. The agency employees thousands of expert analysts who assess the information’s implications for U.S. national security. It is this in-depth analysis that is often presented to the president and Cabinet to inform their decision-making.

Covert action is an activity intended to influence political, economic or military conditions abroad without the role of the U.S. being apparent. Such actions include programs such as disinformation campaigns, counterterrorism operations and military raids such as the one used to kill 9/11 attack organizer Osama bin Laden.

a group of people stand in front of a wall with a three-story concrete building in the background
The CIA tracked 9/11 attack mastermind Osama bin Laden to this house in Pakistan, where U.S. special operations forces killed him.
AP Photo/B.K. Bangash

During the Cold War, from 1947 to 1991, the agency conducted numerous controversial covert actions. These included conducting coups in Iran and Guatemala and attempted or successful political assassinations in Congo, the Dominican Republic, Chile and Cuba. It also carried out highly effective programs such as the U-2 spy plane and Operation Argo, which rescued six Americans stranded in Iran after the 1979 revolution.

Effective espionage and covert action are likely to prove crucial for blunting threats that nations such as China, Russia, Iran and North Korea pose to the U.S. They will be key to monitoring the activities of these nations and enabling the director to deliver timely and valuable analysis to the president.

CIA director’s changed role

During the Cold War, the director of central intelligence had autonomy to conduct these covert actions with limited oversight. The position was extremely powerful at the time because the director was in charge of overseeing all U.S. intelligence activities, not just those of the CIA. This left the director of the CIA as the primary voice on intelligence matters to the president.

Since significant reform of the U.S. intelligence community in 2005 in response to the failure to prevent the 9/11 attacks, the role of the CIA director has changed. The most significant of these changes is that the CIA director no longer manages all U.S. intelligence. The reforms gave that responsibility to the more independent director of national intelligence.

The reform also saw the CIA director’s influence diminished because the position is no longer the primary intelligence adviser to the president. This has created tension between the two positions at times, with the CIA maintaining a high degree of independence from even the director of national intelligence.

In 2017, for example, President Donald Trump restored the CIA director as a formal member of the president’s Cabinet. Later, the CIA director was made a regular attendee of the National Security Council, the president’s principal forum for national security deliberations.

While there is more oversight of the CIA today from Congress and the director of national intelligence, the agency remains relatively independent in conducting espionage and covert action. These include covert actions during the Syrian civil war and during Russia’s invasion of Ukraine.

black and white photo of armed men around a boat on a beach
These Cuban soldiers helped defeat the CIA-organized Bay of Pigs invasion in Cuba in 1961.
Keystone/Getty Images

Another change has been the increased size of the intelligence community. The CIA today is only part of a much larger group of intelligence agencies. These include the Federal Bureau of Investigation, the Defense Intelligence Agency, the National Security Agency and more specialized agencies like the National Geospatial-Intelligence Agency.

In spite of this more capable and larger intelligence community, the CIA remains the premiere U.S. intelligence agency. This ensures that the CIA director will remain a key player in any presidential administration. The director possesses an immense responsibility to protect the U.S. from foreign threats.

Although the CIA director’s role has changed over time, what remains clear is its central importance to the success of U.S. national security efforts. This has become only more apparent given the increasing turbulence in world affairs.

This story is part of a series of profiles of Cabinet and high-level administration positions.The Conversation

Matthew Clary, Senior Lecturer in Political Science, Auburn University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Read More

The post How the CIA director helps the US navigate a world of spies, threats and geopolitical turbulence appeared first on theconversation.com

Continue Reading

The Conversation

Terrorist groups respond to verbal attacks and slights by governments with more violence against civilians

Published

on

theconversation.com – Brandon J. Kinne, Professor of Political Science, University of California, Davis – 2025-01-14 07:48:00

Yazidi women in Iraq mourn the victims of Islamic State group attacks.
Ismael Adnan/SOPA Images/LightRocket via Getty Images

Brandon J. Kinne, University of California, Davis; Iliyan Iliev, The University of Southern Mississippi, and Nahrain Bet Younadam, University of Arizona

After an Islamic State group-inspired attack in New Orleans killed 14 people on New Year’s Day 2025, President Joe Biden warned that terrorists would find “no safe harbor” in the U.S.

Governments often condemn terrorist groups in this way, as well as making threats and engaging in what we call “verbal attacks.”

But such an approach may be counterproductive; extremist groups tend to respond to such comments by ratcheting up violence against civilians. That’s what we found when we analyzed six years of data on incidents of terrorist violence and their proximity to government denunciations.

Our study focused primarily on the Islamic State group.

The extremist organization came to the world’s attention in early 2014, when it began seizing territory in Iraq and Syria. At the height of its power in 2015, the Islamic State group controlled over 100,000 square kilometers (39,000 square miles).

Although it has declined substantially since then, the group remains the world’s deadliest terror organization – responsible for nearly 2,000 deaths in 2023.

The rapid metastasis of the Islamic State group – it has affiliates across the Middle East, North Africa and South Asia – combined with the extreme brutality of its tactics, triggered waves of condemnations by foreign governments. Former U.S. president Barack Obama initially referred to the Islamic State group as the “JV team” in 2014, implying that the group was not as formidable an opponent as more established groups like al-Qaida. A year later, he vowed to “destroy” the group.

Our motivating research question is whether these and similar statements affect terrorists’ behavior.

Traditionally, researchers have dismissed statements like this as “cheap talk.” And government officials similarly do not take seriously the possibility that such statements might have unintended consequences or inflict actual costs.

But when extremist groups commit terror attacks, they always have an audience in mind. And the Islamic State group closely monitors how governments respond to its actions.

Terrorist groups use attacks on civilians to illustrate the extreme measures they are willing to take to achieve their goals. Our research suggests that when governments denounce terrorists, reject their demands or make retaliatory threats, targeted groups infer that they are not being taken seriously. As a result, they commit further atrocities against civilians, with the intent of signaling their intentions and capabilities even more forcefully.

To confirm this, we used a large-scale machine-coded dataset known as the Integrated Crisis Early Warning System to extract daily data on all events involving the Islamic State group for the period 2014 to 2020. We then employed a coding system known as CAMEO to identify events where governments threatened, denounced or otherwise verbally attacked the group.

We found that when governments initiated any form of verbal attack against the organization, the Islamic State group responded by targeting civilians, typically within two days of a verbal attack.


Iliyan Iliev, Nahrain Bet Younadam, Brandon J Kinne, CC BY-SA

Our model showed that every three verbal attacks by governments led to an additional, otherwise unexpected attack by the Islamic State group on civilians. These attacks averaged over six deaths per attack, so the humanitarian consequences of this effect are substantial.

Why it matters

Government leaders face enormous pressures to address national security threats, and terrorism is a powerful source of anxiety for citizens.

Yet, counterterrorism is expensive, risky and logistically difficult.

As such, publicly threatening or denouncing an organization offers a tempting alternative strategy. But there has been little research into how government leaders’ words might backfire, encouraging extremists to attack civilians.

At the same time, although the Islamic State group has diminished greatly in capacity, transnational terrorism continues to flourish. And the resurgence of the Islamic State group remains a threat to security in the Middle East and beyond.

What still isn’t known

We extended the analysis to the terrorist groups Boko Haram in Nigeria and Al-Qaida in Iraq, and we found similar results. But further research is needed to determine whether this pattern holds for terrorist groups in general.

Our theory argues that extremists respond so strongly to verbal attacks because they view those remarks as questioning the group’s credibility – a phenomenon we refer to as a “credibility deficit.”

But terrorists have many motivations, including the desire to control territory and repress dissent. We don’t yet know the magnitude of these influences relative to credibility.

The Research Brief is a short take on interesting academic work.The Conversation

Brandon J. Kinne, Professor of Political Science, University of California, Davis; Iliyan Iliev, Associate Professor of Political Science, The University of Southern Mississippi, and Nahrain Bet Younadam, Postdoctoral Research Associate in the School of Government and Public Policy, University of Arizona

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Read More

The post Terrorist groups respond to verbal attacks and slights by governments with more violence against civilians appeared first on theconversation.com

Continue Reading

Trending