The US space agency NASA says new data from observations of the asteroid (小行星) Bennu still suggests that the object could one day hit Earth. But, the scientists    1    (study) the asteroid predict in a new study that there is very little chance that Bennu    2    (hit) Earth in the coming century.

Bennu and other asteroids are considered near Earth objects. Scientists identify such objects    3    those having the possibility of coming within 50 million kilometers of Earth's orbit. Bennu    4    (discover) in 1999. It is believed    5    (form) more than 4.5 billion years ago. It moves into near-Earth space because of gravitational interactions with other    6    (planet). Bennu makes its closest pass to Earth every six years.

The latest data on Bennu was collected by NASA's Osiris- Rex spacecraft,    7    spent more than two years observing the asteroid. Last October, Osiris-Rex also    8    (success) collected samples (样本) from Bennu. The spacecraft is now on a trip back to Earth, with NASA expecting its    9    (arrive) in September 2023. The main goal of the Osiris-Rex mission was to collect the samples. Scientists say they hope    10    material can help them better understand how the planet formed and how life began on Earth.

Are we alone in the universe? Scientists have spent years     1     (search) deep into space for signs of life beyond our planet. Now they’ve discovered what might be life on Venus.

Venus is the second planet from the sun in our solar system. It’s one of the brightest     2     (object) in the night sky. Several billion years ago, the surfaces of Venus and Earth may have been more similar     3     now. But today, the surface of Venus is too hot for life. And until recently, Venus’s thick clouds were thought to be too poisonous for a living thing     4     (survive) there.

    5     September 14, in the journal Nature Astronomy, scientists reported the discovery of a chemical     6     (call) phosphine(磷化氢 ) in the clouds of Venus. On Earth, phosphine gas     7     (give) off by living things. Scientists aren’t yet able to prove that life on Venus is     8     is producing the phosphine. But they can’t explain the source of the gas in any other way.

The discovery of life beyond Earth would teach us more about the universe     9     our place in it. To Sousa-Silva, Harvard University astrochemist, it would say something about our     10     (important). “I like finding out that we as humans aren’t that special,” she says.

Water doesn't currently exist on Mars' surface, but it used to. About 4 billion years ago, something happened to Mars' atmosphere, and most of the liquid water     1    （disappear） due to harmful radiation. But some of     2     may still be underground. Could those ancient water holes contain life?

China's Tianwen-1 mission will search     3    the existing water by radar fixed on the rover （月球车）.The European Space Agency's spacecraft found evidence for subsurface water,     4    （use） radar from space, but this will be the first time a rover has searched from the ground.

Tianwen-1 will also give China     5    （value） Mars experience and lay foundation for a sample return mission planned for     6    end of the 2020s. Getting Martian samples back to Earth is a top priority for the scientific community. Despite the impressive advances     7    （make） in placing science instruments on spacecraft, only the technology on Earth,     8    can test samples accurately, is to verify the presence or absence of life in a sample.

As of 2020, only NASA has landed and operated spacecraft on Mars     9    （successful）. More countries exploring Mars means more     10    （opportunity） for global cooperation. Space exploration brings out the best in us all. When more nations work together, everyone wins.