1 . Double rainbows are one thing, but a double aurora (极光)? They can happen, though some kinds are rare. One particular red-and-green aurora is especially confusing. Now, images taken by amateur astronomers may help reveal its secrets.

Citizen scientists living in Canada and Finland used cameras to document an unusual combination of auroras in the night sky. Physicists have studied those images to learn what may have caused the unusual light show.

Alan Dyer was outside his home in Strathmore, Canada, when the dancing Northern Lights caught his attention. He grabbed his camera and started filming. "I knew I had something interesting," says Dyer. At first glance, the double aurora looks like a floating slice of watermelon. The green aurora is well-understood. The fruity looking red st rip is more mysterious. Scientists have known about these red auroras for decades. But there's no agreement on how they form. One idea is that Earth's magnetic field can heat up certain areas of the atmosphere. That heat could knock particles (粒子) around, like in proton (质子) rain.

Researchers had seen these two types of auroras occur together before. But it was always mysterious, says Toshi Nishimura, a space physicist at Boston University. After looking at satellite observations along with the images taken by Dyer and others, Nishimura and his team concluded how the two phenomena might be related. The key is the thin rays in the red aurora. They mark the paths of electrons falling through the Earth's magnetic field. That means electron rain appears to cause the red aurora, just as proton rain causes the green one. Both get powered by the solar wind. But the electrons carry less energy than the protons, so they make for a more reddish color.

Electron rain might not be the only way to produce the stable red auroras, though. The results show that what's going on is more complicated than researchers had thought. The auroras Dyer saw could be danger zones for radio communication and GPS systems, says Nishimura.

The citizen scientists who took the photos were a critical part of the new findings, Nishimura says.

4 . Orienteering (定向越野) involves running, jogging or walking, and using a map and compass to move between places. It’s a great way to have fun outdoors with friends and family. The aim is to move between points, called controls, in a certain order in the quickest time. Events are usually held in parks, fields or forests but they can also happen in towns and cities and even school playgrounds. People can take part either as individuals or as a team.

Beginners’ events will have easier controls to find and cover less distance — perhaps a mile or two. For experienced orienteers, the length of the course could be much longer and take in hills and rough ground.

Orienteers are given a “control description sheet” to help them find each point. This sheet has details of features to look for, like paths and rivers, and a code that must match the code at each control. You will either mark your sheet at each control or check in with an electronic card.

When you start orienteering, you will learn map-reading skills. A helpful tip is to keep your thumb on the spot that shows your location on the map. Keep it the right way round: the features in front of you on the ground should be in front of you on the map.

Orienteering maps can have five or six colors. Black areas show human features, like buildings; brown shows the contour (轮廓) lines (height of the land); and blue shows water, such as lakes and rivers. White and green together show woodlands; yellow areas represent grass and open areas. On orienteering maps, a course consists of a triangle, circles, a double circle and sometimes connecting lines. The triangle is the start, the double circle is the finish, and all the circles in between are checkpoints.

As you run between points by what you hope is the quickest route, you can take in the scenery around you and have a great time choosing your path and trying to finish in a fast time.

7 . According to the “Geophysical Research Letters” published on the latest research from the North Pole shows that the Aretic is warming at more than four times the rate of global warming. Climate change has not only brought about an increase in the global average temperature, but also led to the trend of frequent, widespread, strong and concurrent extreme weather and climate events.

Greenland is the largest island in the world. About 3/4 of the area is within the Aretic Circle, and 81% of the area is covered by ice and snow. Greenland’s annual average temperature is below 0℃, and the absolute minimum temperature of the coldest month in the coldest central plateau area reaches minus 70℃, which is the second “cold pole” on earth to Antarctica.

Recently, CNN reported that “due to the continuous high temperature in Europe, the large ice sheet above Greenland has shown signs of melting, and the situation is getting worse. In just 3 days, the average daily the amount of ice melted is as high as 6 billion tons.” The melting water during this period is enough to cover 30.48 cm of West Virginia, USA.

At present, the probability of abnormally high temperature in more than 80% of the world is increasing, which is mainly related to the increase in global carbon dioxide emissions. In fact, over the past century, as humans have increased their use of fossil fuels, rising temperatures have made heat waves more frequent.

Secondly, the heat island effect is also an important reason for the increase of urban temperature. People will increasingly use air conditioners to cool down. The main unit of the air conditioner emits heat to the outside, which is equivalent to forming a cycle, causing the temperature in the city to get higher and higher.

Professor Otto, a climate scientist at Imperial College London, said: “In a few decades, this summer may be quite cool.”

8 . Matt counted his new year gifts one more time as he tucked a robot-shaped eraser into each envelope. He prepared gifts for everyone for the next day's party.

When Matt got to school the next day, he saw a new girl in his classroom. She stood near Ms. Robins and looked around shyly. "This is Dorothy," said Ms. Robins. "Will someone volunteer to show her around today?" Matt raised his hand. He liked helping new kids feel welcome. "Thanks, Matt," Ms. Robins said. "Now let's get busy with our work so we're done in time for the party." That's when Matt realized he didn't have a gift for Dorothy. No one else would have one either. He felt a sad lump in his stomach.

As he showed Dorothy around, he was careful not to mention the party. At lunchtime, he walked Dorothy to the lunchroom, still worried about what would happen at the party. Dorothy had brought a packed lunch, so Matt showed her where she should sit and went back to his usual seat. While eating, Matt suddenly remembered that kids often included candy hearts with the new year gifts they exchanged. An idea popped into his head. He whispered it to the kids around him. Soon everyone at the table was nodding and whispering.

When they were back in the classroom after lunch, Matt told Ms. Robins about their plan. Ms. Robins agreed with a nodding smile. It was math time, so Matt invited Dorothy to study with him. He made sure Dorothy sat with her back to the room so she wouldn't notice her new classmates passing around an exquisite paper bag Ms. Robins prepared to collect their candy hearts.

Before long, it was party time. They played games and then had cookies and juice. Finally, they passed out their gifts. The room buzzed with happy chatter. Matt saw the sad look on Dorothy's face as she glanced at other kids' desks overflowing with envelopes.

"Here's your gift, Dorothy," Matt said, placing the paper bag in front of her. "It's from everyone."

Dorothy stared at the beautiful bag full of "hearts".

"We wanted you to have a special New Year's Day too," said Matt.

"Thank you," Dorothy said, smiling at her new classmates. "It really is a special day!"

9 . Wildlife experts are asking Australians to drive carefully to avoid unnecessary roadkill as native animal numbers drop following years of natural disasters.

Kristie Newton from WIRES said the recent floods across Eastern Queensland and New South Wales could lead to an increase in animal roadkill accidents with wildlife on the move. “This year it might be even worse because they’re traveling a bit further to find food,” Newton said. “Important food sources like grasses have become less and less, forcing many animals to move outside their habitat in search of food, and turn up in unusual places.”

“The fires killed millions and millions of native animals, and now we’ve had the floods. So it’s important that we try and protect what animals we’ve got left.” the wildlife expert said. The 2019-20 bushfires in Australia have affected nearly three billion animals.

According to AAMI Insurance, more than ten percent of all animal roadkill accidents happen in May. More than 15,500 AAMI animal collision claims last year showed that central Victoria’s Heathcote was the country’s most dangerous place for wild animals. Victoria was also the worst state for animal roadkill, with almost one third of animal accidents taking place on Victorian roads. New South Wales and Queensland followed closely behind.

Newton said moving a dead animal off the road can be a good way to prevent unnecessary death. “Birds also come down and feed on those bodies, and we see a lot of them get hit when doing that.” She is also encouraging drivers to do the right thing if they hit an animal. “Please pull over where it is safe to check whether the animal is injured,” said Newton. “For your own safety never set close to an adult kangaroo, even if it’s injured.”