John: Yeah, NASA keeps coming out with announcements every year.
Sarah: We just found out that there's water on Mars - liquid water.
John: Yes, recently they revealed that there's evidence of liquid water.
Sarah: That's crazy.
John: Last year they announced that they definitely found ice - solid water - in the soil. In the soil on Mar's surface the found frozen water. Now they found evidence of liquid water flowing.
Sarah: Do you think people can go to Mars? Do you think we should send people to Mars?
John: I definitely think we can go there. We've already sent a number of spacecraft to Mars, starting with satellites many decades ago. Then there were landers, where satellites landed on the surface and sent data back to Earth. Then we sent the rovers. Little robot cars that drive around on Mars, so we've already successfully sent many missions to Mars. I'm sure we can do it with humans.
Sarah: But none of the satellites or landers or rovers, they've never come back. Do you think we could send people and they'd come back safely?
John: Well, that is a problem. We could definitely send people to Mars, but bringing them back, having the astronauts come back to Earth, would be a much more difficult problem to solve.
Sarah: So you think maybe we would send astronauts to Mars? They would never come back safely?
John: Well, if you think about the old explorers, in the olden days ... explorers used to leave their home, and find new regions and not plan to go back. People used to take a risk, and maybe they couldn't return, so I think there are people who are willing to go on a one-way trip to Mars. I'm sure there are people willing to do that, but are the rest of the people willing to send someone on that mission? I think some people will say yes, and some people will say no. I don't know what the percent would be, but I'm willing to allow someone to do that. If someone says I want to go to Mars. I know it's a one-way trip, but I want to go. I think that's OK. We should let them go.
Sarah: How about you? Would you volunteer to go?
John: Oh, no. Not me. I'm staying here on Earth.
There's evidence of liquid water.
Liquid is a substance that flows freely. Notice the following:
- Most soft drinks are colorful liquids.
- I prefer to use liquid soap.
In the soil on Mar's surface the found frozen water.
Soil is the soft material on the ground such as dirt. Notice the following:
- Plants need soil to grow.
- The farmland has rich soil.
Satellites landed on the surface
A satellite is a vehicle that usually orbits something like a planet and sends back date. Notice the following:
- Japan launched a new weather satellite.
- We get TV broadcasts from a satellite.
We've already sent a number of spacecraft to Mars
A spacecraft is a space vehicle like a rocket or satellite. Notice the following:
- NASA has lots of spacecraft.
- The spacecraft in Star Wars are cool.
Then we sent the rovers.
A rover is a small vehicle used to travel over rough terrain. Notice the following:
- We sent a rover to Mars.
- The rover moves slowly due to its large tires.
People are willing to go on a one-way trip to Mars.
When you are willing to do something, you are eager to do it. You want to do it on your own. Notice the following:
- I am not willing to agree to that.
- She was always willing to help him.
willing • rover • spacecraft