It seems that we are one step closer to finding alien life and maybe a future home for humanity. Scientists from NASA have found a new solar system filled with planets that look like the Earth and could even support life.

The group of seven planets, which orbits a star called Trappist-1, is 39 light years away from the Earth in the constellation of Aquarius(水瓶座). And three of them are in the “habitable zone” - the area around a star where water is most likely to be found. This is important because water is necessary for life.

“This is an amazing planetary(行星的) system - not only because we have found so many planets, but because they are all surprisingly similar in size to the Earth”, astronomer Michael Gillon from the University of Liege in Belgium told The Independent.

Trappist-1 is a “dwarf star(矮星)” which is colder and shines dimmer than our sun. If a person were on one of the seven planets, everything would look a lot darker than usual. The amount of light heading toward our eyes would be about 200 times less than we get from the sun, according to The Independent.

Because of that, Trappist-1, together with many other dwarf stars, was never on the list of places where scientists looked for alien life. But Michael Gillon, lead researcher behind the discovery, decided to give dwarf stars a chance. He built a telescope in Chile to observe 60 of the closest dwarf stars, and it turned out that Trappist-1 was worthy of the effort.

The researchers hope that they can spend more time watching the newly found planets to learn more about them. Even though more research is needed before determining whether these planets could really support life, the discovery is still encouraging. It shows just how many Earth-size planets could be out there.

“[The discovery] gives us a hint that finding a second Earth is not just a matter of if, but when,” NASA scientist Thomas Zurbuchen told The Telegraph.

Everybody loves a fat pay rise. Yet pleasure at your own can disappear if you learn that a colleague has been given a bigger one. Indeed, if he has a reputation for lazy, you might even be angry. Such behaviour is regarded as “all too human,” with the underlying assumption that other animals would not be capable of this finely developed sense of resentment (不满). But a study by Sarah Brosnan and Franks de Waal of Emory University in Atlanta, Georgia, which has just been published in Nature, suggests that it is all too monkey, as well.

The researchers studied the behaviour of female brown capuchin monkeys. They look cute. They are good-natured, co-operative creatures, and they share their food readily. Above all, like their female human counterparts, they tend to pay much closer attention to the value of “goods and services” than males.

Such characteristics make them perfect candidates for Dr. Brosnan’s and Dr. de Waal’s study. The researchers spent two years teaching their monkeys to exchange tokens(代币) for food. Normally, the monkeys were happy enough to exchange pieces of rock for slices of cucumber. However, when two monkeys were placed in separate but connected rooms, so that each could observe what the other was getting in return for its rock, their behaviour became markedly different.

In the world of capuchins, grapes are luxury goods (and much preferable to cucumbers). So when one monkey was handed a grape in exchange for her token, the second was reluctant to hand hers over for a mere piece of cucumber. And if one received a grape without having to provide her token in exchange at all, the other either threw her own token at the researcher or out of the room, or refused to accept the slice of cucumber. Indeed, the mere presence of a grape in the other chamber (without an actual monkey to eat it) was enough to inspire resentment in a female capuchin.

The researchers suggest that capuchin monkeys, tike humans, are guided by social emotions. In the wild, they are a co-operative, group-living species. Such cooperation is likely to be stable only when each animal feels it is not being cheated. Feelings of righteous anger, it seems, are not the preserve of people alone. Refusing a lesser reward completely makes these feelings abundantly clear to other members of the group. However, whether such a sense of fairness evolves independently in capuchins and humans, or whether it stems from the common ancestor that the species had 35 million years ago, is, as yet, an unanswered question.

You return from work on a muggy August evening. Your unwashed teenage son is on the sofa playing Fortnite, as he has been doing for the past eight hours. Your daughter, scrolling through(滚动浏览)Instagram, acknowledges your presence with a rude grunt (咕哝). Not for the first time, you ask yourself: why are school summer holidays so insufferably long?

【小题1】 Many children will return from the long break having forgotten much of what they were taught the previous year. One study from the American South found that this “summer learning loss” could be as high as a quarter of the year’s education. Poor children tend to be the worst affected, since rich ones typically live in homes full of books and are packed off to summer camp to learn robotics, Latin or the flute. A study from Baltimore found that variations in summer loss might possibly account for two-thirds of the achievement gap between rich and poor children by the age of 14-15. Long holidays definitely strain the budgets of poor families, since free school meals stop and extra child care kicks in.

Summer holidays vary greatly from country to country. South Korea children get only three weeks off. Children in Italy and Turkey get a whopping three months. So do those in America, while their parents, unless they are teachers, have an average of only three weeks off a year, among the shortest holidays in the rich world. 【小题2】 But for their children, six weeks out of class is plenty.

It would be unwise to import South Korea’s pressure-cooker approach, in which a single exam determines every child’s future. 【小题3】 Yes, it would cost money, but there are ways to pay for it. One is to have larger classes. Many parents are obsessed with teacher-to-pupil ratios, but there is not enough evidence that they make much difference. The average Japanese lower-secondary class is more than 50% larger than the average British one, but Japanese children get better results.

More time in school need not mean repeating the same old lessons. 【小题4】 And the summer could also be a time for different kinds of learning: critical thinking, practical skills, financial literacy, work placements with local firms—schools should be free to experiment. Space should not be a problem. Many school buildings sit idle in the summer.