2 . The earth is struck daily by 60 tons of rocks from outer space. However, finding these ancient rocks is no easy task. Most meteorites (陨石) fall directly into water. And those that hit land can be difficult to spot among other rocks.

Fortunately for researchers there is one place on Earth where meteorites find it difficult to hide: Antarctica. “There are probably fewer meteorites falling per acre of land in Antarctica than in other parts of the world,” said Ralph Harvey, a professor at Case Western Reserve University. “But if you want to find things that fell from the sky, lay out a big white sheet. And Antarctica is a 5,000-kilometer-wide sheet.”

Finding meteorites in Antarctica is so relatively “easy” compared to the rest of the world that an estimated two-thirds (around 45,000) of those ever discovered have come from the icy continent. The challenge, however, comes not only from the terrible conditions, but also from knowing where to look to make any expedition worthwhile.

In an effort to greatly improve the collection rate of Antarctic meteorites, a Belgian—Dutch team of scientists has unveiled (展示) what they’re calling a “treasure map” for the region. “We expect the treasure map to be 80% accurate,” said Veronica Tollenaar, who led the study.

After landing in the snow in Antarctica, a meteorite will either be directed into the ocean or brought back to the surface of what’s known as a “blue ice” area. As meteorites come out in these special “blue ice” areas, their color contrasts (对比) against the deep blue ice, making them easy to spot. The treasure map marks more than 600 special “blue ice” areas. They estimate that these sites may contain anywhere from 340,000 to 900,000 surface meteorites.

The researchers add that these locations also likely contain rare meteorites, such as angrites, brachinites or even Martian meteorites.

“Collecting these ancient rocks will further improve the understanding of our Solar System,” they write.

NASA announced that it would make 366 precious images of the universe available to the public in April     1     (celebrate) the 30th anniversary (周年) of the Hubble Space Telescope’s launch into space.

    2     site is called “What Did Hubble See on Your Birthday?”. Internet users can find out what beautiful image     3     (take) on their birthday by the telescope (望远镜), as long as they select their birth dates on NASA’s     4     (office) website.

NASA launched the Hubble Space Telescope     5     April 24, 1990. “Hubble explores the universe 24 hours a day, 7 days a week. That     6     (mean) it has recorded some fascinating     7     (wonder) every day of the year, including on your birthday,” said the website.

In the past three decades, scientists     8     have never given up on their dream of space     9     (explore) have been given a brief look at our vast universe thanks to Hubble. During this period, the telescope has become an eye in the sky for astronomers     10     (hope) to explore secrets of the universe. And now, the public will also get a chance to look into the vast and beautiful universe.

8 . Scientists attach great importance to identifying and tracking near-Earth objects because some of them could present threats to our planet. With this in mind. NASA launched a spacecraft last November that aimed to demonstrate a possible defensive method against asteroids that might threaten the earth.

Historically, the American space agency NASA used powerful ground-based telescopes and its NEOWISE spacecraft to identify asteroids and other near-Earth objects, NASA also used tracking systems to follow the movements of asteroids.

Recently, scientists have used a new tool to discover more than 100 asteroids that had not been identified before. The new tool used a complex computing method, which was also called an algorithm, to search for asteroids that had not been discovered before. They were not discoverable because existing telescopes and image examination tools could not recognize them.

The discovery of 104 new asteroids was announced by the American-based non-profit Asteroid Institute. The organization hoped the new asteroid search tool would led to the discovery of more asteroids in the coming years. The Asteroid Institute, which is part of the B612 Foundation, explained on its website that it aimed to combine computer science, instrumentation and astronomy to find and track asteroids. Ed Lu, who is the director of the B612 Foundation and also a former NASA astronaut, said, “Discovering and tracking asteroids is key to understanding our solar system, promoting the development of space and protecting our planet from asteroid impacts.”

The institute called its discovery tool Asteroid Discovery Analysis and Mapping, or ADAM. This system used the algorithm to link points of light in different sky images that were consistent with asteroid orbits. The tool was trained to find asteroids based on existing data and to calculate their orbits well enough to be recognized by international astronomy organizations. Joachim Moeyens, a researcher from the University of Washington said the latest identifications were just the beginning. He predicted the asteroid search tool would result in thousands of new discoveries in the future.

Chinese scientists have contributed to the global effort     1     captured the world’s first image of Sagittarius A, the supermassive black hole at the center of the Milky Way galaxy, according to the Shanghai Astronomical Observatory of the Chinese Academy of Sciences, one of the     2    (participate) in the project.

Experts believe the image of Sagittarius A will help people better understand the extreme celestial objects     3    (call)black holes and the evolution of our galaxy.

Sagittarius A     4    (locate) about 27,000 light years away from our solar system. It has     5     estimated mass of more than 4 million times that of the sun. It’s about 24 million kilometers     6     diameter(直径).

The black hole is now mostly dormant and only     7    (occasional) absorbs nearby gas or dust, but it holds many mysteries that     8    (puzzle) scientists for decades, such as its birth and growth.

Black holes typically form when the nuclear fusion of a very massive star fizzles out     9     it collapses upon itself into a super dense celestial object.

The Event Horizon Telescope held a news conference on Thursday     10    (present) the mug shot of the behemoth lurking behind the clouds of dust and gas that surround the center of our home galaxy.

10 . One of the crucial issues for mankind to solve before landing humans on Mars is that they must find usable water on the barren, reddish planet for the explorers to consume.

A recent finding by Chinese scientists based on data obtained by China’s Martian rover (探测器) Zhurong may have brought that goal closer to reality.

According to data obtained by the rover, they have identified hydrated (含水的) materials at Zhurong’s landing site in the southern part of an impact basin called Utopia Planitia. “These hydrated minerals are associated with bright-toned rocks and are interpreted to be duricrust (铝铁硅钙壳) developed locally. The duricrusts suggest that formation with substantial liquid water originates by either groundwater rising or subsurface ice melting,” reads a paper published in the newest issue of the scientific journal Science Advances.

Liu Yang, lead author of the paper, said their findings indicate that liquid water activities might have been more active than previously thought during the Amazonian Period, which began about 3 billion years ago and remains ongoing. “There is likely to be a large amount of usable water in hydrated minerals around the landing site of Zhurong as well as the vast areas in Mars' northern lowlands,” he added.

Zhurong is the core component (核心部分) of Tianwen-1, the country’s first inter-planetary mission, and is also the sixth rover on the Red Planet, following five from the United States. It is tasked with surveying Mars ’landforms, geological structures, soil characteristics, potential locations of water and ice, and atmospheric and environmental characteristics, as well as magnetic, gravitational and other physical fields.

As of Thursday, Zhurong has worked on Mars for nearly a year — far outliving its three-month life expectancy (预期寿命) and obtained a great deal of data, mission controllers said, adding it still has sufficient energy and is in good condition