This cartoon demonstrates the three-dimensional structure of the pol theta enzyme. Credit: S. Doublie, University of Vermont
Considered the most lethal form of DNA damage, double-strand breaks must be repaired to prevent cell death. In developing therapies for hard-to-treat breast and ovarian cancers in patients with BRCA gene mutations, scientists aim to identify ways to keep cancer cells from using DNA break repair pathways. New findings demonstrate a previously-unknown capability for polymerase theta (pol theta) – a key enzyme in this repair function—that shows promise as a new avenue for treatment development.
The study results are published in Molecular Cell.
Researchers at the University of Vermont (UVM), The University of Texas MD Anderson Cancer Center (MD Anderson), and Yale University discovered that pol theta, previously known to extend DNA in the repair process, is also able to behave like a nuclease and trim DNA.
Because these cancer cells rely on the pol theta pathway to survive and repair double-strand breaks, researchers have been focused on pol theta and trying to find out how to inhibit this pathway.
“Pol theta is a ‘hot’ enzyme right now,” says senior author and self-described “polymerase geek” Sylvie Doublié, Ph.D., professor of microbiology and molecular genetics at the UVM Larner College of Medicine and the UVM Cancer Center. “This is a new activity for pol theta; it’s an elegant way of solving the problem—you only need one enzyme.”
For patients with hard-to-treat cancers, this finding could lead to the development of new therapeutic options, like the Poly-ADP-ribose polymerase (PARP) inhibitors class of drugs that have been used to treat breast and ovarian cancer over the past decade.
“The cell has to decide which function needs to be applied and this trimming activity is a point of vulnerability for pol theta,” says Doublié. One aim of the research is to create conditions where one reaction can be encouraged over the other.
A potential role for such an inhibitor would be to improve ionizing radiation therapy in cancer patients with BRCA1 or BRCA2 mutations.
Doublié’s former doctoral student Karl Zahn, Ph.D., now a postdoctoral fellow at Yale, saw evidence of this dual function in pol theta several years ago while working in Doublié’s lab. He carried out the experiments described in the paper after engaging the expertise of Richard Wood, Ph.D., professor of epigenetics and molecular carcinogenesis at MD Anderson. Wood and Doublié have had a long-term collaboration, funded by a Program Project grant from the National Cancer Institute.
Conducting the experiments, controls, and reproducing the findings took the research team several years but was critical to confirming this discovery.
“It was an unexpected finding, and the biochemistry makes sense, suggesting a way to inhibit the DNA repair process orchestrated by pol theta”, says Wood.
“The trimming reaction is rapid, and many people missed it,” says Doublié, adding that the research team’s patience and work paid off. “‘Chance favors only the prepared mind,'” she says, quoting the late French scientist Louis Pasteur.
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Study identifies never-before-seen dual function in enzyme critical for cancer growth (2021, February 11)
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The 3 Stages of Relapse
A relapse typically doesn’t occur as a spur-of-the-moment event. In most cases, there are three main stages of relapsing. Understanding these stages, and what to do when they occur, can help stop a relapse before it takes effect.
The 3 stages of relapse include:
1. Emotional Relapse
During an emotional relapse, a person is not consciously thinking about drinking. However, their emotions and behaviors are setting the stage for a relapse.
During this stage, denial plays a big role. Many of the signs that occur during emotional relapse are also symptoms of post-acute withdrawal (PAWS). To help minimize the risk of relapse, it is important to recognize that many of the uncomfortable feelings you experience in early addiction recovery could be symptoms of PAWS.
Symptoms of PAWS include:
Foggy thinking/trouble remembering
Urges and cravings
Irritability or hostility
Sleep disturbances, such as insomnia or vivid dreams
Fatigue
Issues with fine motor coordination
Stress sensitivity
Anxiety or panic
Depression
Lack of initiative
Impaired ability to focus
Mood swings
Emotional relapse warning signs include:
Anxiety
Restlessness
Intolerance
Discontent
Anger and irritability
Defensiveness
Mood swings
Bottling up emotions
Isolation and not asking for help
Not attending support groups (or attending and not sharing)
Poor self-care (not eating, sleeping, or practicing good personal hygiene)
(A) X-ray crystal structure of QhpG and schematic of crosslinked QhpC. The substrate QhpC is bound to the pocket formed by the catalytic domain, which includes the FAD cofactor and the small domain. (B) QhpG-catalyzed dihydroxylation reaction. Credit: Osaka University
Investigators from the Institute of Scientific and Industrial Research at Osaka University, together with Hiroshima Institute of Technology, have announced the discovery of a new protein that allows an organism to conduct an initial and essential step in converting amino acid residues on a crosslinked polypeptide into an enzyme cofactor. This research may lead to a better understanding of the biochemistry underlying catalysis in cells.
Every living cell is constantly pulsing with an array of biochemical reactions. The rates of these reactions are controlled by special proteins called enzymes, which catalyze specific processes that would otherwise take much longer. A number of enzymes require specialized molecules called “cofactors,” which can help shuttle electrons back and forth during oxidation-reduction reactions. But these cofactors themselves must be produced by the organisms, and often require the assistance of previously existing proteins.
Now, a team of scientists at Osaka University has identified a novel protein called QhpG that is essential for the biogenesis of the enzyme cofactor cysteine tryptophylquinone (CTQ). By analyzing the mass of the reaction products and determining its crystal structure, they were able to deduce the catalytic function of QhpG, which is adding two hydroxyl groups to a specific tryptophan residue within an active-site subunit QhpC of quinoheme protein amine dehydrogenase, the bacterial enzyme catalyzing the oxidation of various primary amines. The resulting dihydroxylated tryptophan and an adjacent cysteine residue are finally converted to cofactor CTQ.
protein structure. The team then used computer software to simulate the docking of the target molecules, the triply crosslinked polypeptide QhpC, based on the crystal structure they found for QhpG. The two post-translational modifications of QhpC are successively carried out in the modification enzyme complex QhpD-QhpG. “Our findings can be applied to development of novel bioactive peptides using enzymes that modify amino acids,” senior author Toshihide Okajima says. Some of these applications include creating new enzymes for the bioremediation of toxic chemicals.
The article, “Functional and structural characterization of a flavoprotein monooxygenase essential for biogenesis of tryptophylquinone cofactor,” was published in Nature Communications.
More information:
“Functional and structural characterization of a flavoprotein monooxygenase essential for biogenesis of tryptophylquinone cofactor,” Nature Communications (2021). DOI: 10.1038/s41467-021-21200-9
Citation:
The chemistry lab inside cells (2021, February 10)
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Species-independent analytical platforms can facilitate the creation of feedback-controlled high-density agriculture. Credit: Betsy Skrip, Massachusetts Institute of Technology
Researchers from the Disruptive & Sustainable Technologies for Agricultural Precision (DiSTAP) Interdisciplinary Research Group (IRG) of Singapore-MIT Alliance for Research and Technology (SMART), MIT’s research enterprise in Singapore, and Temasek Life Sciences Laboratory (TLL), highlight the potential of rapid and non-destructive analytical tools that provide tissue-cell or organelle-specific information on living plants in real time and can be used on any plant species.
In a perspective paper titled “Species-independent analytical tools for next-generation agriculture,” published in the scientific journal Nature Plants, SMART DiSTAP researchers report that they used two engineered plant nanosensors and portable Raman spectroscopy to detect biotic and abiotic stress, monitor plant hormonal signaling and characterize soil, phytobiome and crop health in a non-invasive or minimally invasive manner. The researchers discuss how the tools bridge the gap between model plants in the laboratory and field application for agriculturally relevant plants. They also provide an assessment of the future outlook, economic potential and implementation strategies for the integration of these technologies in future farming practices.
According to U.N. estimates, the global population is expected to grow by 2 billion within the next 30 years, giving rise to an expected increase in demand for food and agricultural products to feed the growing population. Today, biotic and abiotic environmental stresses such as plant pathogens, sudden fluctuations in temperature, drought, soil salinity, and toxic metal pollution—made worse by climate change—impair crop productivity and lead to significant losses in agriculture yield worldwide.
An estimated 11 to 30% yield loss of five major crops of global importance (wheat, rice maize, potato, and soybean) are caused by crop pathogens and insects; with the highest crop losses observed in regions already suffering from food insecurity. Against this backdrop, research into innovative technologies and tools are required for sustainable agricultural practices and meet the rising demand for food and food security—an issue that has drawn the attention of governments worldwide due to the COVID-19 pandemic.
The Plant nanosensors were developed at SMART DiSTAP. They are smaller than the width of a hair and can be inserted into the tissues and cells of plants to understand complex signaling pathways. The portable Raman spectroscopy, also developed at SMART DiSTAP, is a portable laser-based device that measures molecular vibrations induced by laser excitation, producing highly specific Raman spectral signatures that provide a fingerprint of a plant’s health. These tools are able to monitor stress signals in short time scales, ranging from seconds to minutes, allowing for early detection of stress signals in real-time.
“The use of plant nanosensors and Raman spectroscopy has the potential to advance our understanding of crop health, behavior, and dynamics in agricultural settings,” said Dr. Tedrick Thomas Salim Lew, the paper’s first author and a recent graduate student of the Massachusetts Institute of Technology (MIT). “Plants are highly complex machines within a dynamic ecosystem, and a fundamental study of its internal workings and diverse microbial communities of its ecosystem is important to uncover meaningful information that will be helpful to farmers and enable sustainable farming practices. These next-generation tools can help answer a key challenge in plant biology, which is to bridge the knowledge gap between our understanding of model laboratory-grown plants and agriculturally-relevant crops cultivated in fields or production facilities.”
Early plant stress detection is key to timely intervention and increasing the effectiveness of management decisions for specific types of stress conditions in plants. The development of these tools capable of studying plant health and reporting stress events in real-time will benefit both plant biologists and farmers. The data obtained from these tools can be translated into useful information for farmers to make management decisions in real-time to prevent yield loss and reduced crop quality.
The species-independent tools also offer new study opportunities in plant science for researchers. In contrast to conventional genetic engineering techniques that are only applicable to model plants in laboratory settings, the new tools apply to any plant species which enables the study of agriculturally-relevant crops previously understudied. The adoption of these tools can enhance researchers’ basic understanding of plant science and potentially bridge the gap between model and non-model plants.
“The SMART DiSTAP interdisciplinary team facilitated the work for this paper and we have both experts in engineering new agriculture technologies and potential end-users of these technologies involved in the evaluation process,” said Professor Michael Strano, the paper’s co-corresponding author, DiSTAP co-lead Principal Investigator, and Carbon P. Dubbs Professor of Chemical Engineering at MIT. “It has been the dream of an urban farmer to continually, at all times, engineer optimal growth conditions for plants with precise inputs and tightly controlled variables. These tools open the possibility of real-time feedback control schemes that will accelerate and improve plant growth, yield, nutrition, and culinary properties by providing optimal growth conditions for plants in the future of urban farming.”
“To facilitate widespread adoption of these technologies in agriculture, we have to validate their economic potential and reliability, ensuring that they remain cost-efficient and more effective than existing approaches,” the paper’s co-corresponding author, DiSTAP co-lead Principal Investigator, and Deputy Chairman of TLL Professor Chua Nam Hai explained. “Plant nanosensors and Raman spectroscopy would allow farmers to adjust fertilizer and water usage, based on internal responses within the plant, to optimize growth, driving cost efficiencies in resource utilization. Optimal harvesting conditions may also translate into higher revenue from increased product quality that customers are willing to pay a premium for.”
Collaboration among engineers, plant biologists, and data scientists, and further testing of new tools under field conditions with critical evaluations of their technical robustness and economic potential will be important in ensuring sustainable implementation of technologies in tomorrow’s agriculture.
DiSTAP Scientific Advisory Board Members, Professor Kazuki Saito, Group Director of Metabolomics Research Group at RIKEN Center for Sustainable Resource Science, and Hebrew University of Jerusalem Professor, Oded Shoseyov also co-authored the paper.
Crystal structure, XRD and Raman of WB6 at 165 GPa. Credit: Nilesh P. Salke
Tungsten hexanitride with armchairlike hexazine N6 ring has been synthesized by a group of scientists led by Dr. Jin Liu and his former postdoc Nilesh Salke at HPSTAR (Center for High Pressure Science & Technology Advanced Research). WN6 is a promising high-energy-density and super-hard material. Their findings are published in the recent issue of Physical Review Letters.
Diatomic nitrogen is the most abundant molecule in Earth’s atmosphere accounting for almost 78% volume. The strong triple bond in nitrogen makes it very stable and unreactive at near ambient conditions. However, under intense pressure and high-temperature conditions, nitrogen will behave entirely differently, it can form double- or even single-bonded structure or react with other elements to form novel nitrides. Single-bonded polymeric nitrogen or nitrides possessing single-bonded nitrogen are of great scientific interest as a high-energy-density material. And transition metal nitrides are the very promising candidates that might contain the planar nitrogen hexazine (N6) ring which are predicted to be impossible to stabilize experimentally due to the lone pair repulsion.
The team created WN6 in a laser-heated diamond anvil cell by elemental reaction between tungsten and nitrogen above pressure of about 1.3 Mbar and temperature of ~3500 K. In-situ synchrotron X-ray diffraction (XRD) allowed them to identify the tungsten hexanitride phase, crystallizing with novel armchair-like N6 rings, and the high-pressure Raman spectroscopy measurement confirmed the presence of N-N single bonds in N6 rings. Further theoretical calculations also support their experimental observations.
“The armchair-like hexazine nitrogen sublattice in the WN6 is remarkable and comparable to that in the polymeric nitrogen phases, making it a promising high-energy-density material candidate,” said Dr. Nilesh Salke, now a postdoctoral researcher at the University of Illinois at Chicago.
Additionally, WN6 shows a Vickers hardness of up to 57 GPa, the highest hardness among all transition metal nitrides along with good toughness. They credited the ultra-stiffness of WN6 to balance between the attractive interaction of N6 rings with W atoms and the repulsive interaction of N6 rings with each other based on theoretical calculations.
“To our knowledge, this is the first experimental report on the single-bonded transition metal nitride,” said Dr. Jin Liu, “We believe that this work will stimulate further experimental efforts to synthesize other nitrides with novel structural, chemical, and physical properties.”
“Our experimental demonstration of stabilizing armchairlike hexazine N6 ring in WN6 paves the way for future efforts to stabilize planar hexazine ring,” added Dr. Liu.
More information:
Nilesh P. Salke et al, Tungsten Hexanitride with Single-Bonded Armchairlike Hexazine Structure at High Pressure, Physical Review Letters (2021). DOI: 10.1103/PhysRevLett.126.065702
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varied diet of flowering plants, usually are well camouflaged and do not congregate in groups. Eumaeus’ ranks are notable exceptions; so much so that for years some researchers suggested that Eumaeus might not even be hairstreaks at all. In addition, because of cycads’ ancient evolutionary history, most scientists had assumed that the six members of Eumaeus developed their tolerance for cycasin and their conspicuousness a very long time ago in their evolutionary history.
To settle the matter, Robbins and his colleagues set about sequencing the genomes of Eumaeus’ six members and a bevy of other hairstreaks around three years ago, drawing on the wealth of diverse specimens held in the museum’s collections as well as some samples from wild butterflies. Those results definitively showed that Eumaeus butterflies were not an ancient evolutionary departure from the rest of the hairstreaks. In fact, they are closely related to a pair of rather typical genera called Theorema and Mithras.
The results also showed that the ability to eat poisonous cycads was such a boon to Eumaeus that it spurred a frenzy of rapid evolutionary change that outpaced all other hairstreaks. The team also learned that Eumaeus had split in two evolutionary lines after they began to eat cycads, so they were able to analyze the evolutionary dash twice, including the marked genetic similarities the two lineages had in responding to their new poisonous diet.
When the team started analyzing the Eumaeus genomes, they saw a striking amount of genetic change to parts of these butterflies’ genomes related to building various types of proteins. To narrow down whether these proteins might be related to eating cycads, the researchers compared the Eumaeus genomes to butterflies in Theorema, their closest non-toxic relatives, which have camouflaged, solitary caterpillars that eat a standard range of flowering plants.
Theorema also had some regions of fast evolving DNA that coded the construction of various proteins. When Robbins and his co-authors compared the two genomes they discarded any regions of rapid change that overlapped between the two to hopefully isolate the genetic changes involved in coping with the cycad’s toxins.
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Louisiana State University College of the Coast & Environment Boyd Professor R. Eugene Turner reconstructed a 100-year record chronicling water quality trends in the lower Mississippi River by compiling water quality data collected from 1901 to 2019 by federal and state agencies as well as the New Orleans Sewerage and Water Board. The Mississippi River is the largest river in North America with about 30 million people living within its watershed. Turner focused on data that tracked the water’s acidity through pH levels and concentrations of bacteria, oxygen, lead and sulfate in this study published in Ambio, a journal of the Royal Swedish Academy of Sciences.
Rivers have historically been used as disposal sites worldwide. From the polluted Cuyahoga River in Cleveland, Ohio that caught fire to the Mississippi River where sewage was dumped resulting in increases in lead and decreases in oxygen, rivers were environmentally hazardous until the passage of the U.S. Clean Water Act in 1972. The Clean Water Act as well as the Clean Air Act, the Toxic Substances Control Act and others established a federal structure to reduce pollutant discharges into the environment and gave the Environmental Protection Agency the authority to restrict the amounts and uses of certain toxic chemicals such as lead. Turner’s study assesses changes in water quality before and after the Clean Water Act and Clean Air Act went into effect. The water quality data he compiled were collected from four locations on the southern end of the Mississippi River at St. Francisville, Plaquemine, two locations in New Orleans and at Belle Chasse, Louisiana.
His research found that after these environmental policies were put into place, bacterial concentrations decreased by about 3 orders of magnitude, oxygen content increased, lead concentrations decreased and sulfate concentrations declined less dramatically. His research also found that as sulfur dioxide emissions peaked in 1965, the river’s pH dropped to a low of 5.8. In the U.S., natural water falls between 6.5 and 8.5 with 7.0 being neutral. However, as sulfur dioxide emissions declined in 2019, the pH of the river was restored to an average of 8.2.
“The promulgation and acceptance of the Clean Water Act and Clean Air Act demonstrates how public policy can change for the better and help everyone who is demonstrably ‘downstream’ in a world of cycling pollutants,” Turner said.
Consistent vigilance and monitoring are necessary to ensure water quality in the Mississippi River and northern Gulf of Mexico. Plastics fill oceans, pharmaceuticals are distributed in sewage and COVID-19 virus and other viruses spread in partially treated sewerage wastes from aging septic tanks, unconstrained wetland treatment systems with insufficient hydrologic controls and overloaded treatment systems.
New pollutants are added to the river each year, which will require monitoring and testing. Unfortunately, lead monitoring has stopped, but decades of sustained and effective efforts at a national scale created water quality improvements and are an example for addressing new and existing water quality challenges, Turner said.
More information:
Turner, R.E. Declining bacteria, lead, and sulfate, and rising pH and oxygen in the lower Mississippi River. Ambio (2021). doi.org/10.1007/s13280-020-01499-2
In this illustration, NASA astronauts drill into the Mars’ subsurface. The agency is creating new maps that show where ice is most likely to be easily accessible to future astronauts. Credit: NASA
So you want to build a Mars base. Where to start? Like any human settlement, it would be best located near accessible water. Not only will water be crucial for life-support supplies, it will be used for everything from agriculture to producing the rocket propellant astronauts will need to return to Earth.
Schlepping all that water to Mars would be costly and risky. That’s why NASA has engaged scientists and engineers since 2015 to identify deposits of Martian water ice that could be within reach of astronauts on the planet’s surface. But, of course, water has huge scientific value, too: If present-day microbial life can be found on Mars, it would likely be nearby these water sources as well.
A new study appearing in Nature Astronomy includes a comprehensive map detailing where water ice is most and least likely to be found in the planet’s northern hemisphere. Combining 20 years of data from NASA’s Mars Odyssey, Mars Reconnaissance Orbiter, and the now-inactive Mars Global Surveyor, the paper is the work of a project called Subsurface Water Ice Mapping, or SWIM. The SWIM effort is led by the Planetary Science Institute in Tucson, Arizona, and managed by NASA’s Jet Propulsion Laboratory in Southern California.
“The next frontier for Mars is for human explorers to get below the surface and look for signs of microbial life,” said Richard Davis, who leads NASA’s efforts to find Martian resources in preparation for sending humans to the Red Planet. “We realize we need to make new maps of subsurface ice to improve our knowledge of where that ice is for both scientific discovery and having local resources astronauts can rely on.”
Two views of the northern hemisphere of Mars (orthographic projection centered on the north pole), both with a grey background of shaded relief. On the left, the light grey shading shows the northern ice stability zone, which overlaps with the purple shading of the SWIM study region. On the right, the blue-grey-red shading shows where the SWIM study found evidence for the presence (blue) or absence (red) of buried ice. The intensity of the colors reflect the degree of agreement (or consistency) exhibited by all of the data sets used by the project.
In the near future, NASA plans to hold a workshop for multidisciplinary experts to assess potential human-landing sites on Mars based on this research and other science and engineering criteria. This mapping project could also inform surveys by future orbiters NASA hopes to send to the Red Planet.
NASA recently announced that, along with three international space agencies, the signing of a statement of intent to explore a possible International Mars Ice Mapper mission concept. The statement brings the agencies together to establish a joint concept team to assess mission potential as well as partnership opportunities between NASA, the Agenzia Spaziale Italiana (the Italian Space Agency), the Canadian Space Agency, and the Japan Aerospace Exploration Agency.
Location, location, location
Ask Mars scientists and engineers where the most accessible subsurface ice is, and most will point to the area below Mars’ polar region in the northern hemisphere. On Earth, this region is where you find Canada and Europe; on Mars, it includes the plains of Arcadia Planitia and glacier-filled valleys in Deuteronilus Mensae.
NASA’s Phoenix Mars Lander shows the trench, called ‘Dodo-Goldilocks,’ lacking lumps of ice seen previously. The ice had sublimated, a process similar to evaporation, over the course of four days. Credit: NASA/JPL-Caltech/University of Arizona/Texas A&M University
Such regions represent a literal middle ground between where to find the most water ice (the poles) and where to find the most sunlight and warmth (the equator). The northern midlatitudes also offer favorable elevations for landing. The lower the elevation, the more opportunity a spacecraft has to slow down using friction from the Martian atmosphere during its descent to the surface. That’s especially important for heavy human-class landers, since Mars’ atmosphere is just 1% as dense as Earth’s and thus provides less resistance for incoming spacecraft.
“Ultimately, NASA tasked the SWIM project with figuring out how close to the equator you can go to find subsurface ice,” said Sydney Do, the Mars Water Mapping Project lead at JPL. “Imagine we’ve drawn a squiggly line across Mars representing that ice boundary. This data allows us to draw that line with a finer pen instead of a thick marker and to focus on parts of that line that are closest to the equator.”
But knowing whether a surface is hiding ice isn’t easy. None of the instrument datasets used in the study were designed to measure ice directly, said the Planetary Science Institute’s Gareth Morgan, the SWIM-project co-lead and the paper’s lead author. Instead, each orbiter instrument detects different physical properties—high concentrations of hydrogen, high radar-wave speed, and the rate at which temperature changes in a surface—that can suggest the presence of ice.
“Despite having 20 years of data and a fantastic range of instruments, it’s hard to combine these datasets, because they’re all so different,” Morgan said. “That’s why we assessed the consistency of an ice signal, showing areas where multiple datasets indicate ice is present. If all five datasets point to ice—bingo.”
If, say, only two of them did, the team would try to suss out how consistent the signals were and what other materials could be creating them. While the different datasets weren’t always a perfect fit, they often complemented one another. For example, current radars peer deep underground but don’t see the top 30 to 50 feet (10 to 15 meters) below the surface; a neutron spectrometer aboard one orbiter measured hydrogen in the uppermost soil layer but not below. High-resolution photos revealed ice tossed onto the surface after recent meteorite impacts, providing direct evidence to complement radar and other remote-sensing indicators of water ice.
The image is an excerpt from an observation from NASA’s Mars Reconnaissance Orbiter showing a meteorite impact that excavated this crater on Mars exposed bright ice that had been hidden just beneath the surface at this location. Credit: NASA/JPL-Caltech/Univ. of Arizona
Next steps
While Mars experts pore over these new maps of subsurface ice, NASA is already thinking about what the next steps would be. For one, blind spots in currently available data can be resolved by sending a new radar mission to Mars that could home in on the areas of greatest interest to human-mission planners: water ice in the top layers of the subsurface.
A future radar-focused mission targeting the near surface could also tell scientists more about the mix of materials found in the layer of rock, dust, and other material found on top of ice. Different materials will require specialized tools and approaches for digging, drilling, and accessing water-ice deposits, particularly in the extreme Martian environment.
Mapping efforts in the 2020’s could help make human missions to Mars possible as early as the 2030’s. But before that, there’ll be a robust debate about the location of humanity’s first outpost on Mars: a place where astronauts will have the local water-ice resources needed to sustain them while also being able to make high-value discoveries about the evolution of rocky planets, habitability, and the potential for life on worlds beyond Earth.
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Where should future astronauts land on Mars? Follow the water (2021, February 8)
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The UAE’s “Hope” probe, the first Arab space mission, expected to reach Mars’ orbit on Tuesday, blasted off from Japan in July 2020
The first Arab space mission, the UAE’s “Hope” probe, is expected to reach Mars’ orbit on Tuesday, making it the first of three spacecraft to arrive at the Red Planet this month.
The United Arab Emirates, China and the United States all launched projects to Mars last July, taking advantage of a period when the Earth and Mars are nearest.
If succesful, the wealthy Gulf state will become the fifth nation to ever reach Mars—a venture timed to mark the 50th anniversary of the unification of the UAE—with the China mission due to become the sixth the following day.
Landmarks across the UAE have been lit up in red at night, government accounts emblazoned with the #ArabstoMars hashtag, and on the big day Dubai’s Burj Khalifa, the world’s tallest tower, will be at the centre of a celebratory show.
“Hope”, known as “Al-Amal” in Arabic, will orbit the planet for at least one Martian year, or 687 days, while the Tianwen-1 from China and the Mars 2020 Perseverance rover from the US will both land on Mars’ surface.
Only the US, India, the former Soviet Union and the European Space Agency have successfully reached the Red Planet in the past.
Risky manoeuvre
After blasting off from Japan last July, the Hope mission now faces its “most critical and complex” manoeuvre, according to Emirati officials, with a 50-50 chance of successfully entering a Mars orbit.
Key data on the UAE’s “Al-Amal” hope probe and its journey to Mars
The spacecraft must slow significantly to be captured by Martian gravity, rotating and firing all six of its Delta-V thrusters for 27 minutes to reduce its cruising speed of 121,000 kilometres (about 75,000 miles) per hour to about 18,000 kph.
The process, which will consume half of its fuel, will begin on Tuesday at 1530 GMT and it will take 11 minutes for a signal on its progress to reach ground control.
Omran Sharaf, the UAE mission’s project manager, said it was a “huge honour” to be the first of this year’s missions to reach Mars.
“It is humbling to be in such auspicious and skilled company as we all embark on our missions,” he said. “It was never a race for us. We approach space as a collaborative and inclusive effort.”
While the Hope probe is designed to provide a comprehensive image of the planet’s weather dynamics, it is also a step toward a much more ambitious goal—building a human settlement on Mars within 100 years.
While cementing its status as a key regional player, the UAE also wants the project to serve as a source of inspiration for Arab youth, in a region too often wracked by sectarian conflicts and economic crises.
Hope will use three scientific instruments to monitor the Martian atmosphere, and is expected to begin transmitting information back to Earth in September 2021, with the data available for scientists around the world to study.
Dubai’s Burj Khalifa, the world’s tallest skyscraper, has been lit up in red to celebrate the UAE’s Mars probe
Close behind
China’s Tianwen-1, or “Questions to Heaven”, has already sent back its first image of Mars—a black-and-white photo that showed geological features including the Schiaparelli crater and the Valles Marineris, a vast stretch of canyons on the Martian surface.
The five-tonne Tianwen-1 includes a Mars orbiter, a lander and a solar-powered rover that will for three months study the planet’s soil and atmosphere, take photos, chart maps and look for signs of past life.
China hopes to land the 240-kilogramme rover in May in Utopia, a massive impact basin on Mars. Its orbiter will last for a Martian year.
Tianwen-1 is not China’s first attempt to reach Mars. A previous mission with Russia in 2011 ended prematurely when the launch failed.
NASA’s Perseverance, which is set to touch down on the Red Planet on February 18, will become the fifth rover to complete the voyage since 1997—and all so far have been American.
The “Hope” probe known as “Al-Amal” in Arabic will orbit Mars for at least one Martian year, or 687 days, and is designed to provide a comprehensive image of the Red Planet’s weather
It is on an astrobiology mission to look for signs of ancient microbial life and will attempt to fly a 1.8 kilogramme helicopter-drone on another world for the first time.
Perseverance, capable of autonomously navigating 200 meters (650 feet) per day, will collect rock samples that could provide invaluable clues about whether there was ever past life on Mars.
About the size of a small SUV, it weighs a metric tonne, has 19 cameras and two microphones—which scientists hope will be the first to record sound on Mars.
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UAE’s ‘Hope’ probe to be first in trio of Mars missions (2021, February 7)
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China relies on coal for 60 percent of its energy needs
China has launched the world’s biggest carbon trading system to help lower carbon emissions, but critics and analysts have raised doubts about whether it will have a signficant impact.
China is the world’s biggest emitter of the greenhouse gases that drive climate change, and the scheme is part of its efforts to decarbonise its economy by 2060.
Here are a series of questions and answers on key parts of the emissions trading scheme (ETS):
How does it work?
The scheme, which launched on February 1, effectively puts a price on emitting carbon.
It allows provincial governments to—for the first time—set pollution caps for big power companies, and lets firms buy the right to pollute from others with a lower carbon footprint.
However, in its first phase the scheme only covers the electricity sector, involving 2,200 power producers, which is responsible for 30 percent of China’s total emissions.
Local governments issue a certificate for every metric ton of carbon dioxide or other greenhouse gas equivalent which a company is allowed to emit, and companies pay fines for not complying.
“Companies can either cut emissions or pay to pollute, but the latter will become pricier over time as governments issue fewer pollution permits,” said Zhang Jianyu, vice-president of Environmental Defense Fund China.
And, in a rare move to improve transparency, companies involved in the trading system will have to make their pollution data public.
But analysts have expressed concerns about the likely accuracy of the data, in a country with an authoritarian government that lacks transparency, and low fines for non-compliance.
Will it drive down emissions?
Not nearly as much or as quickly as first hoped.
Initial, broader plans would have covered 70 to 80 percent of China’s emissions. These covered heavy polluters in seven other sectors including aviation, steel and petrochemical manufacturing.
Pollution permits are also being given out for free instead of auctioning them—unlike schemes operating in the European Union or California—which means there is less incentive to slash emissions quickly.
Yan Qin, a carbon analyst at Refinitiv, warned that “in the short term this system is not going to drive emissions reductions”.
Carbon is also expected to be priced very low under the Chinese scheme—about $6 a ton when trading starts—compared with about $36 in the European Union scheme and $17 in California by last year.
Li Shuo from Greenpeace China said these low carbon prices “aren’t enough to push companies to invest in greening their operations”.
Whether the ETS will help reduce emissions in the long run will depend on the stringency of the caps, expanding its scope and strict enforcement.
A commission on carbon prices formed in 2017 and helmed by the economists Joseph Stiglitz and Nicholas Stern indicated that carbon needed to be priced at somewhere between $40 and $80 by 2020 and somewhere in the $50-100 range by 2030 if the markets and prices were to have any impact on investment decisions.
How is China setting emissions caps?
New rules issued by China’s environment ministry in December are urging businesses to reduce carbon intensity—or the amount of pollution produced per unit of GDP—instead of slashing the total amount of greenhouse gas emissions.
Lauri Myllyvirta, a lead analyst at the Centre for Research on Energy and Clean Air, said it was a “subtle but important difference” which could even make new coal power plants more economically attractive.
Pressure from the country’s powerful coal lobby is weighing on efforts to curb emissions.
China relies on coal for 60 percent of its energy needs and since 2011 has burned more coal each year than the rest of the world combined, according to the US Center for Strategic and International Studies.
Capacity keeps growing too, with three times more coal-power generation capacity added in China than in the rest of the world combined in 2020, data from the US think tank Global Energy Monitor showed.
What’s next?
China is drafting a new climate change law that environmentalists say might address some of the shortcomings in the current carbon trading system.
Campaigners are also hoping that the current scheme gets rolled out across more industries, with stricter penalties.
“China… has set a long-term goal to be carbon neutral (but) the carbon market in its current form just isn’t going to play much of a role in realising these ambitions,” Myllyvirta said.
“It could become an important tool in the future, and very fast, if the government decides to give it teeth.”
