Question 110
HardOriginal questionNear the North and South Poles, the night sky sometimes fills with moving curtains of coloured light. These light shows are called auroras. Near the North Pole they are known as the aurora borealis, or northern lights; near the South Pole they are the aurora australis, or southern lights.
They begin at the Sun, which is always sending energy and tiny out into space. Most of these never reach us, because the Earth's field acts as a . During a solar storm, however, the Sun can throw out huge bubbles of gas. Some of the particles become trapped in the Earth's magnetic field and travel along it towards the poles. There they rush down into the atmosphere and react with the gases in the air, which give off light.
The colour depends on the gas. Oxygen gives off green and red light, while nitrogen glows blue and purple.
Auroras are not found only on Earth. Jupiter and Saturn have them too: Saturn's appear as red swirls around its south pole, and Jupiter's have been photographed in ultraviolet light. Scientists think that any planet with an atmosphere and a magnetic field probably has auroras of its own.
According to the passage, which kind of planet would be least likely to have auroras?
Show the answer and explanation
Correct answer: C
Explanation
Scientists think "any planet with an atmosphere and a magnetic field probably has auroras".
Without either, there is nothing to trap the particles and no gases to give off light.
Worth noting
Jupiter is named in the passage as a planet that does have auroras.
- Concept
- Applying a stated rule to a new case
- Typical timeTypical
- 50 s
- Your timeYours
- —
Ten questions from Factual passages, at your own pace.