It sounds like something from science fiction — a space journey into the vast expanse of space, heading towards Mars. While we’re not quite ready to put a person on the land, the question we ask today is: 【小题1】

The space race saw the USA and USSR compete to achieve the first in spaceflight. The Soviet Union released Sputnik 1, an artificial satellite (人造卫星), before anyone else. 【小题2】 Now it appears that Mars is the heaven body of desire. While the reputation and bragging (吹嘘) rights to be the first nation to touch down is an obvious draw, there are other reasons we want to get there.

【小题3】 You only have to look at the fossilized remains of the dinosaurs to see the benefit of finding another habitable planet. While Mars doesn’t have the right conditions to call it home just yet, there’s always the concept of terraforming (地球化) — changing the environment of a planet to meet our needs.

However, not everyone agrees. 【小题4】 He has said the concept of changing habitability of another planet because of the damage we have done to Earth makes no sense when we can simply terraform Earth.

It seems the main reason is the search for extraterrestrial (地球外的) life. 【小题5】 But now seemingly dead, the potential fossils could answer questions about our own evolution and that of our planet. One theory is that bacterial life on our planet didn’t start here, but was transferred via asteroid from Mars.

NASA’s (美国宇航局的) newly announced space tourism program is possibly the biggest mistake in the agency’s history.

Beginning as early as 2020, NASA will offer visits to the International Space Station for $35,000 per night, not including transportation, to pretty much anyone who can pass a physical.

The reason this is a mistake, and a big one, is that NASA has worked for generations to create an image of astronauts as extraordinarily skilled, highly trained, courageous heroes. For example, NASA invites grade schools to participate in creating experiments that are carried on the space station. The astronauts talk to kids from space, sending a message that if you study, work hard and learn math and science, you may reach these heights, too.

According to one report, Las Vegas-based Bigelow Aerospace is making plans to haul four tourists at a time to the space station on SpaceX rockets. U.S. taxpayers forked over a hundred billion dollars to build the International Space Station. It would be nice to try to preserve the image of it as an inspirational achievement, instead of turning it into a flying Howard Johnson’s.

NASA’s press release about the space tourism program tries to cast it as a partnership with the private sector to “provide expanded opportunities” at the space station to “manufacture, market and promote commercial products and services.” But it also states that one goal is “quantifying NASA’s long-term demand for activities in low-Earth orbit.”

The space station has been costing U.S. taxpayers between $1.5 billion and $3 billion each year. If it’s perceived as a private Disneyland for the top tax bracket, public support for the entire space program could be at risk.

But worse, we will have degraded what once inspired us. Sometimes a nation needs stars in its eyes.

Studies of Mercury — the planet closest to the sun-show that it has shrunk by about 11 kilometers across since the solar system’s birth 4.5 billion years ago. As the planet cooled and contracted (收缩), its surface had many long curved ridges (山脊) similar to the wrinkles on a bad apple.

A new research on these ridges, called lobate scarps (瓣状陡坡), has found more of them, with steeper faces, than ever before. The discovery suggests that Mercury shrank by far more than the previous estimate, says Paul Byrne, a planetary scientist. The finding helps explain how Mercury’s huge metallic core (中心) cooled off over time. It may also finally settle the differences between theoretical scientists, who had predicted a lot of shrinkage, with observers who had not found evidence of that — until now. “We are resolving a four-decade-old argument here,” Byrne added.

Planetary scientists have been arguing over Mercury’s lobate scarps ever since the Mariner 10 spacecraft flew past the planet three times in 1974-1975. Researchers can use measurements of the length and height of the scarps to calculate how much planetary shrinkage they represent. That shrinkage is a product of Mercury’s strange structure — “like a core floating through space with a thin outer blanket,” says Byrne. Most of the planet is made of that large core, and so it would have cooled rapidly as heat rushed toward its surface.

The latest data, coming from NASA’s MESSENGER probe and covering the entire planet, showed many lobate scarps with sharp steeper faces, Byrne said. It also uncovered details on another kind of surface feature that may be related to shrinkage. These “wrinkle ridges” are less pronounced than the lobate scarps but may also have formed during contraction. Combined, the data on the lobate scarps and the wrinkle ridges suggest that Mercury’s diameter (直径) has shrunk by 11.4 kilometers, Byrne said.