IELTS Reading Matching Features Example 2

How bugs hitch-hike across the galaxy

A. On the apparently dead lunar surface, a colony of bacteria was thriving. The organisms were not native to the Moon but were visitors from Earth who had hitch-hiked a ride onboard one of Nasa’s five Surveyor probes from the 1960s. To the astonishment of biologists, between 50 and 100 Streptococcus bacteria survived the journey across space, at an average temperature 20 degrees above absolute zero with no source of energy or water, and stayed alive on the Moon in a camera for three years. Captain Conrad, who returned the bacteria to Earth, was later to confess: ‘I always thought the most significant thing we ever found on the whole Moon was the little bacteria that came back and lived’. Beagle’s heat shield doubled as its biological shield. So once the instruments were encased and sealed, the craft could be brought back into the real world. The shield heated up to 1,700 degrees on its descent through the Martian atmosphere, so bugs on the casing were not a worry. Mars Express – the craft carrying Beagle – did not need sterilising. Its trajectory was designed so that if something went wrong, the craft would not simply crash into the planet. Its course could be corrected enroute.

B. Eventually, space scientists hope to return samples of Mars to Earth. While the risks of alien bacteria proving hazardous on Earth may be remote, the rocks will still need to be quarantined. Moon rocks from Apollo were analysed in vacuum glove boxes for the first two missions. Later, researchers stored rocks in nitrogen. Prof Pillinger believed the first Mars rocks should be sterilised before they are studied on Earth. ‘For security purposes, it would be the most sensible thing to do. You don’t have to sterilise it all, you can contain some of it and then sterilise the sample you want to look at, but it would lower the risk and make it easier to analyse.’

1. Surveyor probe
2. Beagle 2
3. Mars express 
4. Apollo craft

The second answer is in the first paragraph, eighth line; “Beagle’s heat shield was also its ‘biological shield’. It was intended that it became so hot that no bacteria could survive on it. Therefore, bacteria on the ‘casing’ (outer structure) were not a problem.”

For the third question, the answer is toward the end of the first paragraph, eleventh line; “Mars Express was designed so that its ‘trajectory’ (the direction of its flight) could be changed during its journey (’corrected en route’) if something went wrong.”

For the fourth question, the answer is in the second paragraph; “At first, moon rocks found on Apollo missions were brought back in vacuum glove boxes, and in later missions, they were kept in nitrogen.”