These findings are good news for life in the universe as they dispel concerns that potentially habitable planets could not form too close to very massive stars. Previously, scientists thought the intensity of ultraviolet (紫外线的) radiation produced by massive stars would interfere (干扰) with the distribution of dust and gas in planet-forming stars, possibly preventing the formation of rocky planets like Earth, for instance. The NGC 6357 group contains more than ten super bright and massive stars, suggesting most of the group’s matter is exposed to high levels of ultraviolet radiation.

Using first-of-their-kind observations from the James Webb Space Telescope. a University of Minnesota Twin Cities-led team looked more than 13 billion years into the past to discover a unique, minuscule galaxy cluster (星系团) that generated new stars at an extremely high rate for its size. The galaxy is one of the smallest ever discovered at this distance —around 500 million years after the Big Bang — and could help astronomers learn more about galaxies that were present shortly after the universe came into existence.

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Fiery Visitors from Outer Space

1. On the next clear summer night, look up into the sky. If you are lucky, you may see a “shooting star”. They look just like stars falling down from the sky.

2. But shooting stars are not stars at all. The real name for a shooting star is “meteor”. There are millions of meteors out in space. They are pieces of rock and metal. When they are in space, meteors do not glow. In fact, we can’t see them at all. But when a meteor comes close to the earth, it starts to fall toward the earth. As it passes through the air, it gets very hot. It starts to glow, and finally it begins to burn. We see the burning meteor as a shooting star.

3. Sometimes meteors travel by themselves in space. But many meteors travel in groups called swarms. The swarms have orbits like planets have. They pass close to the earth every year. A famous swarm is the Perseid swarm. It passes close to the earth in summer, usually in August. Each year a few meteors from the Perseid swarm fall to the earth, so August is a good month to watch for shooting stars.

4. Most meteors are small, so they burn up before they crash into the earth and are buried in the ground. Once a meteor reaches the earth, we call it a meteorite. The biggest meteorite, which weighs seventy tons, landed in Africa.