# Life at a Mountain-Top Observatory

IELTS Academic Reading - 13 questions - 20 minutes - Table completion, True / False / Not Given

Source: Written by Testmigo.

## The passage

You should spend about 20 minutes on Questions 1-13, which are based on the passage below.

At several of the world's leading observatories, a medical check is a normal part of the job, because the telescopes stand on mountains where the air is thin. Astronomers choose these places for good reasons. The higher a telescope is, the less atmosphere lies between it and the objects it studies, and at the best sites the clouds usually stay below the summit. Dry air matters as well. Water vapour in the atmosphere absorbs much of the faint radiation that reaches us from space, especially the millimetre and submillimetre waves that reveal cold gas and dust. Clear views of the sky therefore come at a price, and it is paid by the people who keep the instruments running.

One of the most extreme workplaces of this kind is the Atacama Large Millimeter/submillimeter Array, known as ALMA, in northern Chile. Its 66 antennas are spread across the Chajnantor plateau, about 5,000 metres above sea level, in one of the driest places on Earth. Yet the observatory's staff spend most of their time far lower down, at an Operations Support Facility 2,900 metres up. Only those who maintain the antennas or move them to new positions need to visit the high site, a drive of about 45 minutes that takes them more than 2,000 metres higher. Staff work on a roster of eight days at the observatory followed by six days off, and their time at the top is increased step by step. Nobody goes up on the first day of a roster. The limit is then four hours on the second day, six on the third and eight from the fourth day onwards.

The main danger is hypoxia, a shortage of oxygen in the body. According to ALMA's safety manager, it can harm a worker's sleep, attention span and short-term memory, so the rules are strict. Every worker has a high-altitude medical evaluation once a year, which is more often than the Chilean authorities require. Above 3,000 metres, carrying portable oxygen is compulsory, and the big, heavy cylinders used in the past have been replaced by light tanks made of carbon fibre. The technical building on the plateau is now permanently supplied with extra oxygen. Drivers on the mountain road must have a co-pilot, staff work in teams of at least two, and no one is permitted to sleep at the high site.

Conditions are less severe on Mauna Kea, a volcano on the island of Hawaii that is home to several major telescopes. Its summit is 4,205 metres high, and the air there holds about 40 per cent less oxygen than at sea level. Members of the public who drive up are asked to spend at least half an hour at a visitor information station at around 2,800 metres before going any higher. Pregnant women, children under 13 and anyone who has been scuba diving in the previous 24 hours are advised to go no further than this point. The astronomers and technicians who work at the summit do not live there either. Instead, they stay at Hale Pohaku, whose name means 'stone house' in Hawaiian. Built at an intermediate height, it has living facilities for up to 72 people.

Night work brings its own difficulties. Telescopes that collect visible light can only be used in darkness, so the astronomers who use them have always worked through the night. At the W. M. Keck Observatory on Mauna Kea, however, this has changed. All observing on the Keck telescopes now takes place remotely, either from special rooms at the observatory's headquarters in Waimea, a town about 32 kilometres from the summit, or from other approved remote locations. The observatory states that it no longer supports observers working at the summit.

The Roque de los Muchachos Observatory on La Palma, one of Spain's Canary Islands, is lower again, with its main telescopes at about 2,400 metres. It sits on the rim of an ancient volcanic crater and is usually above the clouds. From the island's airport, the road up winds for more than 40 kilometres through hundreds of bends. Close to the telescopes is a residencia, a building where staff and visiting scientists can sleep and eat. Because someone may be sleeping at any hour of the day or night, everyone is asked to avoid making noise in and around the building. After dark, drivers should also switch off any unnecessary lights and use as little light as possible, or none at all.

The island as a whole helps to protect these conditions. In 1988 the Spanish parliament passed a law, usually known as the Sky Law, which controls outdoor lighting on La Palma. The same law limits radio and other electromagnetic signals that could interfere with the instruments, and it regulates the routes of aircraft flying over the observatories. For the people who work on these mountains, then, the job involves much more than looking at the sky. It also means following careful rules about oxygen, sleep, light and noise, designed to protect both the workers and the view of the universe.

## Questions

### Questions 1-6: Table completion

Complete the table below. Choose ONE WORD AND/OR A NUMBER from the passage for each answer.

Observatory | Altitude of the site | Where people are based | Rules and practices
ALMA, Chile | about 5,000 m | staff spend most of their time at a support facility at **(1)** _____ m | workers must carry portable **(2)** _____ above 3,000 m; nobody is allowed to **(3)** _____ at the high site
Mauna Kea, Hawaii | 4,205 m | summit staff live at Hale Pohaku, which has room for up to **(4)** _____ people | Keck astronomers can observe remotely from the headquarters in **(5)** _____
Roque de los Muchachos, La Palma | about 2,400 m | a residencia where people sleep and eat | people must not make **(6)** _____ near the residencia; drivers use little or no light at night

### Questions 7-13: True / False / Not Given

Do the following statements agree with the information given in the passage? Choose TRUE if the statement agrees with the information, FALSE if the statement contradicts the information, or NOT GIVEN if there is no information on this.

7. Moisture in the air can prevent some signals from space from reaching telescopes.

8. Most people employed at ALMA work at the antenna site on a daily basis.

9. ALMA checks the health of its workers more frequently than national rules require.

10. Several ALMA employees have left their jobs because of the effects of hypoxia.

11. Visitors to Mauna Kea are advised to wait at a lower point for a period before continuing towards the summit.

12. Astronomers using the Keck telescopes can still choose to observe from the summit if they wish.

13. The Sky Law was introduced after astronomers complained about lighting on La Palma.

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