Level 1 - Absolute Beginner
Scientists want to send people to Mars. The trip is very long. They ask: Can the heart stay strong in space?
A new study looked at astronauts on the space station. They stayed there for six months. At first, their hearts got a little smaller.
But the astronauts did exercise every day. Their hearts became healthy again. Exercise is very important in space.
- Mars
- A red planet near Earth.
- heart
- The body part that pumps blood.
- astronaut
- A person who travels in space.
- space station
- A big home in space where people work.
- exercise
- Moving your body to stay strong.
- study
- A careful look at a question.
- healthy
- Strong and well.
- trip
- A journey.
Level 2 - Elementary
A long trip to Mars could take months in space with very little gravity. Doctors worry about astronauts' hearts. A new study in the journal Circulation checked how well hearts do on a long space mission.
Researchers followed about a dozen astronauts during six-month stays on the International Space Station. They used ultrasound scans before, during and after each mission. In the first two weeks, the hearts shrank slightly and changed shape.
Over time the problems got better, thanks to regular exercise. After the astronauts returned to Earth, the team tested them on a tilting table that copies Mars gravity. They showed no big signs of strain.
- gravity
- The force that pulls things toward a planet.
- journal
- A magazine where scientists publish research.
- mission
- A special trip with a task to do.
- ultrasound
- A scan that uses sound waves to see inside the body.
- shrink
- To become smaller.
- strain
- Too much stress on the body.
- tilting table
- A table that can lean to copy different gravity.
- regular
- Done often, at the same times.
Level 3 - Intermediate
Before humans can travel to Mars, doctors need to know whether the cardiovascular system can survive months of weightlessness and then cope with the pull of Martian gravity, about 38 percent of Earth's. A study published in the journal Circulation, by researchers from Northwestern Medicine, UT Southwestern Medical Center and UTHealth Houston, offers encouraging evidence.
The team monitored 13 astronauts, according to most reports, during six-month missions on the International Space Station, using ultrasound scans before, during and after flight. In the first two weeks in orbit every astronaut showed changes in heart structure and function, and their hearts shrank slightly. Those changes gradually improved, which the authors link to consistent exercise under NASA's countermeasures program.
After landing, the astronauts were placed on a tilt table that simulated Martian gravity. They showed no significant signs of cardiovascular strain. The researchers caution that the sample is small and that a real Mars mission would last far longer, but the results suggest that exercise could be the main defence of the heart on the way.
- cardiovascular
- Relating to the heart and blood vessels.
- weightlessness
- The feeling of having no weight in orbit.
- encouraging
- Giving hope.
- monitored
- Watched and checked regularly.
- structure
- The way something is built or arranged.
- countermeasures
- Actions taken to reduce a problem.
- simulated
- Imitated to test real conditions.
- sample
- A small group used to represent a larger one.
Level 4 - Advanced
Among the many obstacles to a crewed Mars mission, the behaviour of the human heart in prolonged weightlessness has long sat near the top of flight surgeons' worry lists. A new study in Circulation, by teams at Northwestern Medicine, UT Southwestern Medical Center and UTHealth Houston, provides some of the most reassuring data yet. It followed 13 astronauts, by most accounts, through six-month stints on the International Space Station, imaging their hearts with ultrasound before, during and after flight.
The early picture was not benign. Within two weeks of reaching orbit, every astronaut exhibited alterations in cardiac structure and function, and their hearts shrank modestly, a plausible consequence of the heart no longer working against gravity. Yet those deviations gradually receded in crew members who adhered to NASA's exercise countermeasures program, suggesting that sustained training can preserve cardiac fitness over months.
On return, volunteers were placed on a tilt table that reproduced Martian gravity, roughly 38 percent of Earth's, and displayed no significant cardiovascular strain. The authors temper their optimism: the cohort is small, six months is far shorter than a Mars round trip, and radiation exposure is a separate threat. Even so, the findings reframe exercise from a pleasant routine into essential medical equipment for deep space.
- prolonged
- Lasting a long time.
- reassuring
- Making someone feel less worried.
- benign
- Not harmful.
- alterations
- Changes.
- deviations
- Departures from what is normal.
- adhered to
- Followed closely.
- cohort
- A group of people studied together.
- temper
- To moderate or reduce in strength.
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