Trees can benefit the environment in a vast number of ways. Not only do they turn carbon dioxide into oxygen, thus providing the basis of the environment which sustains all life on Earth, but they can also clear the air of pollutants and dangerous substances. Due to this, they are often used by urban planners to reduce air and noise pollution, as well as beautify areas. However, when it comes to their role as pollution-fighters in cities, trees also have some downsides. Firstly, they take a long time to grow and secondly, dense (密集的) urban areas are also not ideal for planting large numbers of trees, and it is often these areas that are most in need of pollution reduction.

That’s why a Mexican startup, BiomiTech, has created an artificial tree called “BioUrban” that can do the work of an entire small forest. The tree, which uses a special microalgae (微藻) developed by BiomiTech to carry out the processes of natural trees, could be one way of improving air quality in areas lacking in green spaces.

Measuring 4.2 meters tall and nearly 3 meters wide, the BioUrban looks something like a cross between a tree and a post-modernist high-rise, with a steel trunk that radiates rising bands of concentric metal. After polluted air has entered the BioUrban, the algae gets to work, using natural processes to turn the pollutants into clean oxygen. The company claims that a single BioUrban could do the work of around 368 real trees —pumping out 2,890 clean breathfuls of air a day.

Mexico is certainly no stranger to air pollution. On average, Mexico City often has a suspended air pollutant density twice the World Health Organization’s maximum recommended amount. It is not uncommon in Mexico City for schools to be closed, and people urged to stay indoors, due to the levels of pollution in the city.

The vast majority of this pollution comes from the city’s estimated 3 million cars. The dense urban nature of the city also means it is often difficult to create meaningfully sized parks in certain areas. It is BiomiTech’s goal to provide viable(切实可行的) solutions for these locations, and to reduce air pollution in certain targeted areas, such as around schools, hospitals and homes for the elderly, as well as places frequented by pedestrians.

Currently, BiomiTech has installed three BioUrban trees across Central and South America One has been “planted” in Puebla, Mexico -- the home of BiomiTech, while the others have been sent to Colombia and Peru. Turkey has recently put in an order for two BioUrbans, while Mexico City and Monterrey in northern Mexico are also eyeing up the project.

Despite the claims of efficiency of the BioUrban, Jaime Ferrier, a founding partner in BiomiTech, is also eager to insist BiomiTech isn’t out to supersede trees in urban areas, only to provide solutions for areas where planting trees is not viable.

A world in which extinct creatures could be brought back to life came a step closer yesterday. Australian scientists have managed to extract a gene from a preserved sample of a Tasmanian tiger and make it active. The breakthrough has left them dreaming that one day they will be able to recreate the animal, which died out more than 70 years ago. And if it can be done with the Tasmanian tiger, it may also be possible to resurrect (复活) creatures that have been extinct for far longer.

“There used to be a time when extinction meant forever, but no more, ” said Professor Mike Archer. “We are now able to seriously challenge whether those animals that have gone for ever. What has been achieved is a very important step in bringing back those animals that are extinct. And while I think that technically it is still pretty difficult at the moment, we can now see the possibilities. I’m personally convinced that the Tasmanian tiger will be brought back to life in my lifetime.”

The breakthrough came after nine years of experiments by scientists at the University of Melbourne, who extracted a gene from one of several tigers preserved in alcohol in a Melbourne museum. They removed the equivalent gene from a mouse embryo implanted the tiger gene and then watched as the mouse continued to grow normally, suggesting the tiger gene had been activated.

Team leader Dr. Andrew Pask said it was the first time DNA from an extinct species had been used to “induce (引起) a functional response in another living organism”.

However, the animal’s entire gene structure would have to be revived in the same way to even begin the possibility of bringing the Tasmanian tiger back from the dead.

Mick Mooney, a wildlife officer of the Tasmanian Government, was worried that such developments could encourage people’s indifference to the protection of endangered species.

“If people think that we can bring animals back to life after they’ve gone, they will start saying that there is nothing to worry about because we can fix it up later.”

The movie Moonfall follows the story of a mysterious force knocking the moon from its orbit. Although it’s just a Hollywood movie, is there any fact behind the fiction (虚构的事)? Would it be possible to change the moon’s orbit around Earth?

One way for the orbit of an object in space to change would be if it were hit by another object.

This risk is one area of focus for NASA’s Center for Near-Earth Object Studies (CNEOS). CNEOS identifies and tracks near-Earth objects (NEOs), such as asteroids (小行星) and comets (彗星). They then determine whether the object creates a threat to Earth, the moon, or other neighbors.

Size is a significant factor when determining the risk created by an object from space. If the impact of an asteroid could affect the moon’s orbit, the asteroid “would have to be at least as big as the moon itself”, Paul Chodas, manager of NASA’s NEO office, told Live Science.

Due to the size of the moon, “it would have to be a huge object that would have to hit it at high speed”, he added. Because of the incredibly low chance of an object the size of the moon wandering into our solar system, it can therefore be determined that the chance of the moon’s orbit changing enough for it to hit Earth is minuscule.

Viewers of the night sky are convinced that the moon isn’t going anywhere anytime soon. However, although it’s unlikely to ever hit our planet, the moon still has an impact on life on Earth. A study from NASA states that the moon’s orbit is likely to begin “wobbling (摇晃)” sometime in the 2030s. This is a natural event that occurs every 18 years.

This period will see tides (潮汐) around the world “amplified (放大): High tides get higher, and low tides get lower”, which creates a risk to coastal cities around the globe, according to NASA.