Imagem de fundo

Mark the alternative that presents the correct statement...

Moss in space: spores survive nine-month ride outside of the ISS


By Nicola Davis


01 Matt Damon’s character grew potatoes for survival in the movie “The Martian,” but

02 researchers say mosses could one day help ____ (turn) the dust and rocks of other planets into

03 fertile soil. Physcomitrella patens, or “spreading earthmoss,” is already known as a pioneering

04 species – mainly for ____ (be) an early plant on the scene in areas of barren mud. Now,

05 researchers have ____ (find) that spores of the moss can ____ (survive) for at least nine months

06 stuck to the outside of the International Space Station (ISS) and still reproduce once back on

07 Earth.

08 Although the plant is inedible, researchers say the findings could be important for space

09 exploration. Dr. Tomomichi Fujita, the lead author of the study, from Hokkaido University in

10 Japan, said: “While moss may not be on the menu, its resilience offers insights into developing

11 sustainable life-support systems in space. Mosses could help with oxygen generation, humidity

12 control, or even soil formation.” It is not the first time researchers have highlighted the

13 remarkable survival abilities of moss, or sent such species to the ISS. Indeed, such plants are

14 known to tolerate a host of extreme conditions on Earth. At the same time, scientists have found

15 that the desert moss species Syntrichia caninervis can withstand Mars-like conditions in

16 experiments on Earth.

17 Writing in the journal iScience, Fujita and colleagues report how they exposed three

18 different moss structures to a simulated space environment on Earth. They found that moss

19 spores encased in a structure known as a sporangium were the most resilient and were able to

20 germinate after exposure to UVC radiation levels that exceeded 100,000 joules per square metre.

21 Further tests suggested these encased spores were also resilient to vacuum conditions,

22 deep-freezing, high temperatures, and radiation within a vacuum. The researchers then sent

23 encased spores to the ISS on board the Cygnus NG-17 spacecraft. These were attached to the

24 outside of the ISS in sample holders with different filter settings and left there for nine months.

25 After the samples were returned to Earth, the researchers found that all showed high rates

26 of germination, noting that even those that had been fully exposed to UV radiation in space had

27 an 86% germination rate – compared with a 97% germination rate for spores that had remained

28 on Earth. However, a type of chlorophyll in the space-exposed samples showed signs of

29 degradation. “If such spores can endure long-term exposure during interplanetary travel and

30 then successfully revive upon rehydration and warming, they could one day contribute to

31 establishing basic ecosystems beyond Earth,” Fujita said. He noted that the study focused only

32 on survival under space exposure: “Whether moss can germinate and grow under various

33 extraterrestrial conditions – including different gravity levels, atmospheric compositions and

34 radiation levels – remains an open question.”

35 Dr. Agata Zupanska, of the SETI Institute, who was not involved in the work, welcomed

36 the study but said it was already known that dormant, desiccated biological forms, such as

37 spores or seeds, exhibited significantly greater resistance to environmental extremes than

38 hydrated cells or tissues. She said similar seed exposure experiments, including on space crop

39 seeds, had already been conducted outside the ISS. Zupanska also stressed that the external

40 ISS environment, while harsh, did not fully represent the complexities of true deep space

41 conditions, including those on the Moon or Mars. “The value of space plants is realized only if

42 they can actively grow and thrive away from Earth,” she said. “While spore resilience is important,

43 it represents only an initial step toward the broader goals of growing plants in extraterrestrial

44 environments.”


(Available at: theguardian.com/science/2025/nov/20/moss-spores-survive-outside-international-spacestation-iss – text specially adapted for this test).

Mark the alternative that presents the correct statement about the highlighted word “While” (l. 10) in the context presented in the text.


A

It means “during the time that, or at the same time as”.


B

It means “compared with the fact that”.


C

It could be replaced by “although” with no significant changes in meaning or sentence structure.


D

It means “a length of time”.


E

It could be replaced by “but” with no significant changes in meaning or sentence structure.