Page 81 - You - South Africa (February 2020)

YOU PRIMARY SCHOOL

NOW
YOU KNOW THE IMPACT
Large meteorites
such as the Tswaing When the meteorite hit, a crater formed
one could hit Earth at and the meteorite and all rock formations
any time, but so far and life forms in a 1,13km radius of the
it’s happened only crater simply vaporised because of the
about once very incredible heat the impact generated.
1 600 years. Material vaporises 1,13km

SALT PAN
The lake in the middle of the crater is small – it has a di-
ameter of 100m and is only 3m deep at its deepest point
in the middle of the crater. The water is made up of foun- THE CRATER
tain water, groundwater and rainwater and has a high salt
concentration. Salt was mined here from 1912 until 1956, Diameter: 1,13km HOWA CRATER FORMS
when it was no longer commercially viable. The water The incredible impact of a meteorite as it hits
here is 13 times saltier than the Dead Sea in Israel. the planet’s surface causes a round hole (impact
crater) to form. The Tswaing crater is one of
about 170 known impact craters worldwide. The
Vredefort crater in the Free State is the largest
verified impact crater on Earth. Measuring more
than 300km across, it was formed when a
meteor the size of Table Mountain collided with
Earth FOUR million years ago.
Meteorite
impact

Shockwave

The energy of a fast-travelling object hit-
ting Earth’s surface is transformed into
intense heat- and shockwaves.

Shattered
material
ejected

MUSEUM FOR PRESERVATION
Tswaing Meteorite Crater is preserved in
a museum of 2 000 hectare (2 800 soccer Rebound
pitches). The museum is also known for
its 480 plant species, 240 bird species After the rock is compressed by the
rock
the
the
After
compressed
by
is
and game such as kudu, impala and zebra. impact, it almost immediately re-
bounds outward – the ejection phase.
Melting

The intense heat melts some of the
material shot from the crater.
METEOROID, METEOR is called a meteor. When you see a Rocks and debris fall
AND METEORITE beam of moving light in the night sky back to earth
B A meteoroid is a small piece of – a so-called “shooting star” – you’re
rock that’s broken off a comet or seeing a meteor as it’s being burnt up
asteroid and is orbiting the sun. in the atmosphere.
Larger rocks are called asteroids. B If a meteor enters Earth’s atmos- Fracture
B A meteoroid or asteroid that burns phere without burning up and hits the system
up upon entering Earth’s atmosphere surface, it’s called a meteorite.
Ejected material falls back to earth, set-
tling on the crater’s rim. There’s a fracture
system in the rockbed under the crater.

SOURCES: TSHWANE.GOV.ZA, MIELIESTRONK.COM, GAUTENG.NET, NASA.GOV, SMITHSONIANCHANNEL.COM,
GO.DISCOVERY.COM/TV-SHOWS/AFRICA, SPACE.COM, PASSC.NET/EARTHIMPACTDATABASE, BRANDSOUTHAFRICA.COM you.co.za 6 FEBRUARY 2020 | 79