Question 5
Passage to evaluate:
On 30 June 1908, a farmer in central Siberia saw a raging forest fire. He heard sounds like cannons. The blast knocked down about 80 million trees over an area of 2150 km². This incident is known as the Tunguska event.
Scientists debated for many years about what could have caused this event. In 2013, fragments from the Tunguska site were found and analysed. Scientists think that the incident was caused by a comet. Comets are made of rock and ice. Although a comet is smaller than an asteroid, it could strike Earth at high speeds and so cause much more damage than a larger asteroid.
The comet involved in the Tunguska event was captured in the Earth–Moon system and remained in Earth's orbit for a long time. It gradually broke into pieces and caused unusual twilights over northern Europe between 25 June and 1 July in 1908.
What do scientists now think about the cause of the Tunguska event? What supported their belief?
On 30 June 1908, a farmer in central Siberia saw a raging forest fire. He heard sounds like cannons. The blast knocked down about 80 million trees over an area of 2150 km². This incident is known as the Tunguska event.
Scientists debated for many years about what could have caused this event. In 2013, fragments from the Tunguska site were found and analysed. Scientists think that the incident was caused by a comet. Comets are made of rock and ice. Although a comet is smaller than an asteroid, it could strike Earth at high speeds and so cause much more damage than a larger asteroid.
The comet involved in the Tunguska event was captured in the Earth–Moon system and remained in Earth's orbit for a long time. It gradually broke into pieces and caused unusual twilights over northern Europe between 25 June and 1 July in 1908.
What do scientists now think about the cause of the Tunguska event? What supported their belief?
