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China builds the world’s first artificial moon

Chinese scientists have built an ‘artificial moon’ possessing lunar-like gravity to help them prepare astronauts for future exploration missions. The structure uses a powerful magnetic field to produce the celestial landscape — an approach inspired by experiments once used to levitate a frog.

The key component is a vacuum chamber that houses an artificial moon measuring 60cm (about 2 feet) in diameter. Image credits: Li Ruilin, China University of Mining and Technology

Preparing to colonize the moon

Simulating low gravity on Earth is a complex process. Current techniques require either flying a plane that enters a free fall and then climbs back up again or jumping off a drop tower — but these both last mere minutes. With the new invention, the magnetic field can be switched on or off as needed, producing no gravity, lunar gravity, or earth-level gravity instantly. It is also strong enough to magnetize and levitate other objects against the gravitational force for as long as needed.

All of this means that scientists will be able to test equipment in the extreme simulated environment to prevent costly mistakes. This is beneficial as problems can arise in missions due to the lack of atmosphere on the moon, meaning the temperature changes quickly and dramatically. And in low gravity, rocks and dust may behave in a completely different way than on Earth – as they are more loosely bound to each other.

Engineers from the China University of Mining and Technology built the facility (which they plan to launch in the coming months) in the eastern city of Xuzhou, in Jiangsu province. A vacuum chamber, containing no air, houses a mini “moon” measuring 60cm (about 2 feet) in diameter at its heart. The artificial landscape consists of rocks and dust as light as those found on the lunar surface-where gravity is about one-sixth as powerful as that on Earth–due to powerful magnets that levitate the room above the ground. They plan to test a host of technologies whose primary purpose is to perform tasks and build structures on the surface of the Earth’s only natural satellite.

Group leader Li Ruilin from the China University of Mining and Technology says it’s the “first of its kind in the world” that will take lunar simulation to a whole new level. Adding that their artificial moon makes gravity “disappear.” For “as long as you want,” he adds.

In an interview with the South China Morning Post, the team explains that some experiments take just a few seconds, such as an impact test. Meanwhile, others like creep testing (where the amount a material deforms under stress is measured) can take several days.

Li said astronauts could also use it to determine whether 3D printing structures on the surface is possible rather than deploying heavy equipment they can’t use on the mission. He continues:

“Some experiments conducted in the simulated environment can also give us some important clues, such as where to look for water trapped under the surface.”

It could also help assess whether a permanent human settlement could be built there, including issues like how well the surface traps heat.

From amphibians to artificial celestial bodies

The group explains that the idea originates from Russian-born UK-based physicist Andre Geim’s experiments which saw him levitate a frog with a magnet – that gained him a satirical Ig Nobel Prize in 2000, which celebrates science that “first makes people laugh, and then think.” Geim also won a Nobel Prize in Physics in 2010 for his work on graphene.

The foundation of his work involves a phenomenon known as diamagnetic levitation, where scientists apply an external magnetic force to any material. In turn, this field induces a weak repulsion between the object and the magnets, causing it to drift away from them and ‘float’ in midair.

For this to happen, the magnetic force must be strong enough to ‘magnetize’ the atoms that make up a material. Essentially, the atoms inside the object (or frog) acts as tiny magnets, subject to the magnetic force existing around them. If the magnet is powerful enough, it will change the direction of the electrons revolving around the atom’s nuclei, allowing them to produce a magnetic field to repulse the magnets.

Diamagnetic levitation of a tiny horse. Image credits: Pieter Kuiper / Wiki Commons.

Different substances on Earth have varying degrees of diamagnetism which affect their ability to levitate under a magnetic field; adding a vacuum, as was done here, allowed the researchers to produce an isolated chamber that mimics a microgravity environment.

However, simulating the harsh lunar environment was no easy task as the magnetic force needed is so strong it could tear apart components such as superconducting wires. It also affected the many metallic parts necessary for the vacuum chamber, which do not function properly near a powerful magnet.

To counteract this, the team came up with several technical innovations, including simulating lunar dust that could float a lot easier in the magnetic field and replacing steel with aluminum in many of the critical components.

The new space race

This breakthrough signals China’s intent to take first place in the international space race. That includes its lunar exploration program (named after the mythical moon goddess Chang’e), whose recent missions include landing a rover on the dark side of the moon in 2019 and 2020 that saw rock samples brought back to Earth for the first time in over 40 years.

Next, China wants to establish a joint lunar research base with Russia, which could start as soon as 2027.  

The new simulator will help China better prepare for its future space missions. For instance, the Chang’e 5 mission returned with far fewer rock samples than planned in December 2020, as the drill hit unexpected resistance. Previous missions led by Russia and the US have also had related issues.

Experiments conducted on a smaller prototype simulator suggested drill resistance on the moon could be much higher than predicted by purely computational models, according to a study by the Xuzhou team published in the Journal of China University of Mining and Technology. The authors hope this paper will enable space engineers across the globe (and in the future, the moon) to alter their equipment before launching multi-billion dollar missions.

The team is adamant that the facility will be open to researchers worldwide, and that includes Geim. “We definitely welcome Professor Geim to come and share more great ideas with us,” Li said.

Moon.

Chinese Moon Station planned for ‘in about ten years’

Beijing wants to have a research station up and running on the Moon within a decade.

Moon.

Image via Pixabay.

Last January, China put a rover on the far side of the moon — the only country to have ever achieved this feat. Now, the country plans another new first, state-owned media reported on Wednesday, citing a space-programme official.

Made on the moon

The Tiangong — “Heavenly Palace” — is planned to go into orbit in 2022, head of the China National Space Administration Zhang Kejian said during a speech marking “Space Day”, reports Xinhua. He added that plans are set to launch a Mars probe by 2020 and confirmed that a fourth lunar probe, the Chang’e-5, will be launched by the end of the year.

Tiangong will be built on the moon’s south pole and manned missions carried out “in about ten years”, Xinhua writes. It is intended to replace the International Space Station, the ISS, in housing humanity’s space-farers. The ISS is scheduled for retirement in 2024. Note that at the time of writing this, China is not an ISS partner and no Chinese nationals have, so far, been aboard the station. The country has maintained its own space programme and space station (Tiangong 1).

And it hasn’t been too shabby at it, either. China is the second-largest spender in civil and military space programmes, with a budget of around $10 billion (as estimated by the Organization for Economic Cooperation and Development in 2013). This mission will bring China to the moon for the second time this year, after Chang’e 4 landed there in January. Chang’e-5 was delayed after its planned carrier, the Long March 5 Y2 rocket, failed during a separate launch in July 2017.

Although they appear identical, baking powder and baking soda are slightly different. Credit: Eat By Date.

What’s the difference between baking soda and baking powder: science to the rescue

Although they appear identical, baking powder and baking soda are slightly different. Credit: Eat By Date.

Although they appear identical, baking powder and baking soda are slightly different. Credit: Eat By Date.

Baking soda and baking powder look and sound the same. To make matters even more confusing, they’re often used in the same recipes. However, knowing what sets these two popular ingredients apart could mean the difference between the perfect baked goods or a smooshed fiasco.

What’s baking soda

Baking soda is, essentially, ground up rock — which means it can last indefinitely (if properly stored). More specifically, baking soda is the colloquial term for sodium bicarbonate, a base that reacts quite energetically when encountering an acid such as buttermilk, yogurt, or vinegar (our brains register acid substances as ‘sour’). Mixing baking soda with an acid will produce carbon dioxide — because in this kitchen this reaction usually takes place in a liquid, it also produces bubbles. This property is what makes the substance so useful for bakers. Mix some baking soda into the proper dough, and it will generate carbon dioxide. As the mixture stiffens and the gas escapes, enlarged air pockets are left behind, making the end product fluffy and soft.

Due to this behavior, you’ll often see baking soda mentioned in recipes which include many acidic ingredients like molasses, maple syrup, lemon juice, and pumpkin. In such cases, baking soda works as a leavener, helping the dough rise.

When added to a mixture, baking soda will raise the pH, slowing down protein coagulation — the process that leads to the stiffening of a food as it cooks or bakes. This helps the bake good spread before it sets, helping the food bake more evenly.

Baking soda is also an excellent cleaning agent.  It’s a super-effective (but gentle) abrasive and is a great natural deodorizer, so it’s helpful in all sorts of cleaning emergencies, from unclogging drains to deodorizing the carpet.

Someone who sure loves baking soda…

What’s baking powder

Sometimes, you don’t want the rising to take place all at once, which is where baking powder comes in. Baking powder is a mix made from baking soda (sodium bicarbonate) and two acids for it to interact with and produce CO2 gas at different stages of the baking process. This is “double acting” baking powder; single-acting baking powder contains only one acid, which reacts fully when you combine it with another liquid.

One of the acids in baking powder is monocalcium phosphate, which unlike most acids — like, say, vinegar — doesn’t immediately react with the sodium bicarbonate while it’s dry. It’s only when the sodium bicarbonate is wet, such as when it’s stirred into a wet dough, that the two ingredients begin to react, releasing CO2 bubbles and causing chemical leavening.

Baking powder usually contains a second acid, typically sodium acid pyrophosphate or sodium aluminum sulfate (soda alum), which extends the chemical leavening process. Neither of the two acids will react with the base until the sodium bicarbonate is both wet and hot — in other words, not until you put the dough in the oven. This way, the batter can rise for a longer period of time, leading to a fluffier cake or muffin. Without the two special kinds of acids, baking powder’s heavy lifting powers in the oven would be gone — and we’d all end up with some pathetic, saggy bake goods.

Since baking powder is only one-fourth baking soda, it is also just one-fourth as powerful as baking soda. The upside, when using baking powder, it that it isn’t necessary to add an acid. Instead, baking powder starts to work when any liquid is added.

Both baking powder and baking soda need to be stored in a cool and dry place. The extra moisture in the air can start the reaction between the acids and base. And like baking soda, it is important to bake the mixture right away, or else the mixture will collapse.

So, there you have it: baking soda is made out of a single ingredient, while baking powder is a mix of baking soda and at least one acid. But which of the two should you use in the kitchen? That’s simple: when baking a recipe which already contains an acid as one of the ingredients, use baking soda. If there are no acids in your recipe, use baking powder instead.

Happy baking!

Illustration of Musk's vision for a Mars colony. "The base starts with one ship, then multiple ships, then we start building out the city and making the city bigger, and even bigger. Over time terraforming Mars and making it really a nice place to be," he said.

Elon Musk publishes new academic paper detailing his plans to colonize Mars

SpaceX’s founder and CEO published an academic paper earlier this month outlining his vision for a future where the Red Planet is permanently inhabited.

Illustration of Musk's vision for a Mars colony. "The base starts with one ship, then multiple ships, then we start building out the city and making the city bigger, and even bigger. Over time terraforming Mars and making it really a nice place to be," he said.

Illustration of Musk’s vision for a Mars colony. “The base starts with one ship, then multiple ships, then we start building out the city and making the city bigger, and even bigger. Over time terraforming Mars and making it really a nice place to be,” he said.

The paper published in the journal New Space is based on Elon Musk’s October 2017 talk that he gave in Australia. This is his second published academic paper. Previously, in 2016,  New Space also published a summary of Musk’s first audacious vision for Mars.

If you followed last year’s presentation, as well as Musk’s SXSW appearance, you won’t be particularly surprised by the content of this paper. However, there are some juicy details as to how the entrepreneur plans to fly SpaceX’s Big Falcon Rocket (BFR) fully reusable rocket system to Mars.

BFR has larger payload capacity than Saturn V, while being fully reusable. Credit: Elon Musk/SpaceX.

BFR has larger payload capacity than Saturn V, while being fully reusable. Credit: Elon Musk/SpaceX.

The 348-foot-tall (106-meter) BFR system is powered by 42 Raptor engines and should be fully reusable. According to the latest design outlined in the new academic paper, BFT will be capable of carrying up to 100 people in a pressurized passenger space that’s larger than that of an Airbus A380 airplane. BFR consists of a 190-foot (58-meter) tall booster for its first stage, and a 157-foot (48-meter) tall spaceship that also doubles as a second stage. Besides people, the launch system will be capable of ferrying cargo across the globe or to and from the International Space Station. A BFR flight could take a person from Los Angeles to New York in 25 minutes. Being capable of launching satellites, BFR will also become an important contributor to the company’s bottom line. Eventually, the BFT will make all other SpaceX vehicles obsolete.

“We want to have one system—one booster and one ship—that replaces Falcon 9, Falcon Heavy and Dragon. If we can do that, then all the resources that are used for Falcon 9, Falcon Heavy and Dragon can be applied to this system. That’s really fundamental,” Musk wrote in his paper.

To propel it to Mars, the BFR will be fitted with a huge a 39-foot (12-meter) tank, which can fit 265,000 gallons (a thousand cubic meters) of liquid nitrogen. To contain the fuel, SpaceX engineers designed a new carbon fiber matrix that is much stronger and better suited for cryo than anything before. The tank will support refueling operations in orbit. This latter key step is currently being perfect in the Dargon capsule, which already has automated rendezvous and docking capabilities with the International Space Station.

In his most recent public appearance, Musk said that he’d like to see the first BFR take off for Mars as early as 2022. A second trip planned for 2024 would leave with a crew. “People have told me that my timelines, historically, have been optimistic,” Musk said at SXSW. The company plans on test-launching the first BFR on short “up-and-down flights” before the summer of 2019.

“We’ve already started building the system—the tooling for the main tanks has been ordered, the facility is being built and we will start construction of the first ship around the second quarter of next year. In about six to nine months we should start building the first ship. I feel fairly confident that we can complete the ship and be ready for a launch in about five years. Five years seems like a long time to me. The area under the curve of resources over that period of time should enable this time frame to be met, but if not this time frame, I think pretty soon thereafter. But that is our goal, to try to make the 2022 Mars rendezvous. The Earth-Mars synchronization happens roughly every two years, so every two years there is an opportunity to fly to Mars,” Musk wrote.

Musk did not address all the practicalities of how the first manned crew will establish a Martian colony in his new paper. At SXSW, however, Musk at least acknowledged that these first missions will not be for the faint of heart.

“For the people who go to Mars, it’ll be far more dangerous. It kind of reads like Shackleton’s ad for Antarctic explorers. ‘Difficult, dangerous, good chance you’ll die. Excitement for those who survive.’ That kind of thing,” the entrepreneur warned.

“There’s already people who want to go in the beginning. There will be some for whom the excitement of exploration and the next frontier exceeds the danger,” Musk continued.

A major difference between DNA and RNA could explain why one is the go-to blueprint for life

A new study could finally explain why our cells rely on DNA, and not its molecular relative RNA, to store and pass on genetic data. The findings show that RNA breaks apart when it tries to incorporate changes — such as chemical damage to the molecule — while DNA can twist and bend its shape to allow for changes.

Image via pixabay

The most important thing for any living thing on Earth is to pass on its genes to offspring. Life everywhere feeds, fights and flees all in the hopes that it can eventually bring about more life in its image. But all that effort would be for nothing if genetic information couldn’t be safely stored for when it’s needed. Two molecules are responsible for carrying this information — RNA, which is a simpler single-strand molecule, and DNA which is a more complex double-strand molecule.

But up to now no one really knew why most cells favor DNA to store this genetic data over RNA. But a new study lead by Hashim Al-Hashimi from the Duke University School of Medicine might have found the answer: DNA can accommodate damage in its structure which would cause RNA to break down.

“For something as fundamental as the double helix, it is amazing that we are discovering these basic properties so late in the game,” said lead researcher .

“We need to continue to zoom in to obtain a deeper understanding regarding these basic molecules of life.”

You’re probably familiar with the double-helix model of DNA. When they first proposed it in 1953, Watson and Crick predicted how the base pairs ( A&T. C&G ) bind to form up the whole. Two strands of DNA line up and link by bonding these pairs, and end up looking kind of like a ladder with the bonds being the rungs.

So these bonds were called Watson-Crick base pairs. But researchers struggled to find evidence that the pairs were binding in the way Watson and Crick predicted. Then in 1959, biochemist Karst Hoogsteen took a picture of an A–T base pair, finding a more skewed geometry than expected, with one base rotated 180 degrees relative to the other — and these were called Hoogsteen pairs. In more recent times, researchers have observed both Watson-Crick and Hoogsteen base pairs in images of DNA.

Al-Hashimi and his team stumbled onto something five years ago that no one has ever observed before: DNA pairs that shift back and forth between Watson-Crick and Hoogsteen bonds. They found that DNA employs Hoogsteen bonds when there’s a protein bond to a DNA site – or the bases suffered chemical damage. Once the damage is fixed or the protein is released, the DNA goes back to Watson-Crick bonds. The discovery was big in itself, but now the team has shown that RNA doesn’t have the ability. This could explain why DNA forms the blueprint — it can absorb chemical changes and repair damage, RNA becomes too stiff and falls apart.

“In DNA this modification is a form of damage, and it can readily be absorbed by flipping the base and forming a Hoogsteen base pair. In contrast, the same modification severely disrupts the double helical structure of RNA,” said one of the team, Huiqing Zhou.

“The finding will likely rewrite textbook coverage of the difference between the two purveyors of genetic information, DNA and RNA,” said a Duke University press release.

DNA (left) can form Hoogsteen bonding to incorporate damaged base-pairs, while RNA (right) falls apart in the same case.
Image credits Huiqing Zhou.

The team figured this out by using RNA and DNA molecules to create double-helices, then observed how their base pairs form bonds using advanced imaging techniques. At any one time, around 1 percent of DNA bases were shifting into Hoogsteen pairs, they found. The RNA strands however didn’t do the same.

They tested RNA double-helices under a host of conditions, but couldn’t determine them to naturally form Hoogsteen pairs. When they forced the molecules to form such pairs, the RNA strands fell apart completely. This happens because RNA double-helices are more tightly packed than DNA, and can’t change direction without hitting something or shifting atoms around, which makes the structure critically unstable.

“There is an amazing complexity built into these simple beautiful structures, whole new layers or dimensions that we have been blinded to because we didn’t have the tools to see them, until now,” said Al-Hashimi.

Further research is needed to determine if DNA’s flexibility compared to RNA is what lead to it becoming the go-to molecule for storing genetic data, but if confirmed, it could help us understand why life on Earth evolved into what we see today.

The full paper, “Scientists have just uncovered a major difference between DNA and RNA” has been published in the journal Nature Structural & Molecular Biology.