TS ICET 24 May 2018 Shift 1 Paper

Read the following passage and answer questions 191-195: For centuries sky watchers have reported seeing mysterious flashes of light on the surface of the Moon. Modem astronomers have observed the same phenomenon, but no one has been able to satisfactorily explain how or why the Moon sporadically sparks. However, researchers now believe they have found the cause. Researchers have examined the chemical content of Moon rocks retrieved by astronauts during the Apollo missions and have found that they contain volatile gases such as helium, hydrogen and argon. The researchers suggest that stray electrons, freed when the rock cracks, may ignite these gases. Indeed lunar rock samples when fractured in the lab, throw off sparks. What causes these rocks to crack on the lunar surface? The flashes are most often seen at the borders between sunlight and shade on the Moon, where the surface is being either intensely heated or cooled. A sudden change in temperature may cause thermal cracking. Another possibility is that meteors may strike the rocks and cause them to crack. Finally, lunar rocks may be fractured by seismic events - in other words, by tiny moonquakes.