Remember solar roadways, where solar panels were fitted in roads? I thought it was the worst transportation idea ever until Musk’s Boring Company came along — the only place where solar panels were fitted was under my basement floor. Although, now I would say putting solar panels in Musk’s tunnels(隧道) is worse.

However, placing solar panels in roads is available due to the fact that this resource is everywhere in the sun and that there will be a lot of electric cars someday. But there is another kind of road called the railroad that might be a better place for solar panels. And that’s what is happening in Germany, where solar panels are being fitted between the rails.

As estimated, 100 kilowatts of electricity can be generated every one kilometer of railway line. Since the rail network in Germany is over 60,000 kilometers long, the power to be generated is comparable to the output of five nuclear power plants in total.Undoubtedly, the potential could be huge.

Therefore, I think putting solar panels in railways better than roadways. First, trains generally stay on the rails, so there is no need to have solar panels designed to take any serious load. Although there is a serious amount of vibration(振动), the panels wouldn’t shake apart because they are not connected to the tracks. On the other hand, the power from solar panels can be supplied to overhead lines to train stations or to the consumer and buildings alongside the rail lines.

German railways have been trying to show good reasons for using hydrogen-powered trains because it was too expensive to electrify many of their lines, so turning their rail beds into power sources might change the economics. Besides, railways are much wider than the track, and it makes sense to place the panels next to the track, pointing in a suitable direction instead of lying flat.

But still, solar railways make sense in a way solar roadways have never done.

A robot space mission has successfully brought samples of rocks and soil from the Moon back to Earth for the first time since the 1970s. The capsule from China’s Chang’e mission landed in Inner Mongolia in December 2020, carrying with it around two kilograms of Moon material.

The unmanned Chang’e-5 spacecraft was launched in November 2020. After a 250,000-mile journey to the Moon, it entered orbit and released a small landing vehicle that fell towards the surface. Using rockets to slow its speed, the lander made a soft landing on a 1,300-metre volcanic hill called Mons Rumker, in an area called the Ocean of Storms.

The lander used a scoop (铲) and a drill fitted to a robot arm to tunnel two meters into the ground, collecting samples of rock and soil. It then blasted off from the surface, returned to the main spacecraft and automatically transferred its samples, ready for the journey back to Earth.

This is the first time in nearly 45 years that a spacecraft has got Moon rocks back. Most of the Moon material we have on Earth was brought back by astronauts during the US Apollo missions of the late 1960s and early 1970s. A little more came with robot landers from the Soviet Union (a country composed of Russia and its nearby neighbors) around the same time. The new samples are thought to be around 1.3 billion years old and have been taken to China’s capital, Beijing, for study. It’s hoped that they will allow scientists to work out more accurately the age of the Moon and other solar system objects. Xiao Long, an expert in space rocks at China’s University of Geosciences, said that the samples could “rewrite the history of the Moon”.

Rainforests, it turns out, are not created equal. Take the Amazon rainforest, an area that covers about 7 million square kilometers. But within that huge expanse are all kinds of ecological zones, and some of these zones, says Greg Asner, are a lot more crowded than others.

“Some forests have many species of trees,” he said, “others have few. Many forests are unique from others in terms of their overall species composition…” And all of these different small areas of forest exist within the giant space that is the Amazon Rainforest.

So Asner, using the signature technique called airborne laser-guided imaging spectroscopy, began to map these different zones from the air. “By mapping the traits of tropical forests from above,” he explains, “we are, for the first time, able to understand how forest composition varies geographically.”

The results show up in multicolored maps, with each color representing different kinds of species, different kinds of trees, the different kinds of chemical they are producing and using, and even the amount of biodiversity, the animal and plant species that live within each zone.

Armed with this information, Asner says decision-makers now have “a first-time way to decide whether any given forest geography is protected well enough or not. If not, then new protections can be put in place to save a given forest from destruction.”

Asner says the information is a great way for decision-makers to develop a “cost-benefit ratio type analysis.”   Conservation efforts can be expensive, so armed with this information, government leaders can ensure they are making the most of their conservation dollars by focusing on areas that are the most biologically diverse or unique.

The next step, Asner says, is to take his project global, and to put his eyes even higher in the sky, on orbital satellites. “The technique we developed and applied to map Peru is ready to go global.” Asner said. “We want to put the required instrumentation on an Earth-orbiting satellite, to map the planet every month, which will give the best possible view of how the world’s biodiversity is changing, and where to put much needed protections.