Page 42 - index

2020 ‫מועד קיץ‬ - 41 - ‫ פרק ראשון‬- ‫אנגלית‬

Text II (Questions 18-22)

(1) Every year, Earth is showered by an estimated 100,000 tons of material from outer
space. This extraterrestrial debris ranges in size from fine dust to huge chunks of stone.
The tiniest particles, called micrometeorites, fall constantly and arrive unnoticed. Much
larger are meteors – rocks that are burned by friction as they pass through Earth's

(5) atmosphere. As they fall, meteors produce a bright streak of light that can often be seen
in a clear night sky. For this reason, they are also referred to as shooting stars. The

relatively few meteors that survive the descent through the atmosphere and land on
Earth's surface are known as meteorites. These can be as large as boulders, weighing
100 kilograms or more, but the vast majority are very small. There are two kinds of
(10) meteorites. Iron meteorites are composed of about 90 percent iron; stony meteorites
are made up of iron, silicon, magnesium, oxygen, and other elements.

Meteorites can be identified by several distinctive features. They are denser than
rocks formed on Earth and have a black crust created when their surfaces melted as they
fell through the atmosphere. Some are marked by thumbprint-size depressions called

(15) regmaglypts, which also result from surface melting. A meteorite whose arrival is
observed and is recovered soon afterward is a ‫״‬fall‫״‬. A ‫״‬find‫ ״‬is a meteorite that is
discovered only after it has fallen. Whether meteorites are finds or falls, they are always
named after the place where they land. Many are on display in museum collections.
For example, the Nantan meteorite, a 70-kilogram rock that fell in 1516 in Nantan

(20) County, Guangxi, China, is housed in the rocks and minerals area of the Oxford
University Museum of Natural History.

Meteorites are an exciting source of knowledge. They provide significant clues
about the structure of Earth, the beginnings of life on our planet, and the origin, age,
and evolution of the solar system. Indeed, apart from the lunar rocks brought back from

(25) space missions, meteorites are the only material evidence we have from the universe
beyond our planet.

Questions

18. The main purpose of the first paragraph is to discuss -

(1) different types of extraterrestrial material
(2) the weight and size of meteorites
(3) how much space debris lands on Earth
(4) what meteorites are composed of

)‫© כל הזכויות שמורות למרכז ארצי לבחינות ולהערכה (ע"ר‬
.‫ בלא אישור בכתב מהמרכז הארצי לבחינות ולהערכה‬- ‫ כולה או חלקים ממנה‬- ‫ או ללמדה‬,‫אין להעתיק או להפיץ בחינה זו או קטעים ממנה בכל צורה ובכל אמצעי‬