Our Solar System Mercury

8/14/2019 Our Solar System Mercury

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Mercury

Compiled by Donnette E Davis

www.staidenshomeschool.com


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Our Solar System

St Aidens Homeschool 2009 ~ All Rights Reserved Donnette E Davis 26

Mercury

Mercury is the closest planet to the Sun. It is a terrestrial planet. That means a

planet made from rock like Earth. It does not have a gas atmosphere, so there is

no weather. For a long time, only one spacecraft, Mariner 10, had visitedMercury. In January 2008, the MESSENGER spacecraft went by Mercury. It will go

by Mercury two more times before starting to go around the planet in 2011.

How Big Is Mercury?

Mercury is 4879 km across. Mercury's diameter is just less than half the diameter

of the Earth. It is the smallest planet in the Solar System. Only dwarf planets like

Pluto are smaller. Mercury's small size and its closeness to the Sun sometimes

make it difficult to see without a telescope or binoculars. The best time to spot

Mercury in the sky is just after the sun goes down at night or shortly before it rises

in the morning.

What is Mercury's surface like?

Mercury has craters like those on the Earth's moon. The largest crater on Mercury

is the Caloris Basin. It is about 1300 km wide. It was created by a huge asteroidhitting Mercury. The asteroid was probably 100 km wide, but it hit Mercury's

surface so hard that it made a much bigger hole.

'Mercury Facts'

Mercury orbits around the Sunfaster than any other planet.

Mercury's surface temperaturecan vary from -180C (-300F)

to 430C (800F). On Earth,

the hottest temperature wasrecorded at 58C (136F).

There may be ice on the topand bottom of Mercury.


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Our Solar System


The surface also has big cliffs called scarps. They were made long ago when

Mercury cooled down. It shrank, causing the surface to get wrinkled in some

places. This wrinkling created the scarps.

How long is a day on this planet?

Mercuryrotates (spins around) much more slowly than the Earth. It takes Mercury

58 days to spin once. Because Mercury orbits the sun very quickly, a day on

Mercury lasts longer than 58 days. If you were standing on Mercury, at the

equator and timed how long it took the sun to go from directly overhead to

sunset to sunrise and then rise directly overhead again, it would take 176 Earth

days. These long days and nights allow for the temperatures to rise as high, and

fall as low, as they do.

How long is a year on Mercury?

Mercury has the shortest year in the Solar System. It is about 88 Earth days long.

It used to be believed that the same side of Mercury always faced the Sun. In

order for this to be true, Mercury would have to take the same amount of time to

rotate (spin around) as it does to circle the sun. Through careful observation we

now know that Mercury's rotation is somewhat faster than its orbit. Because of

the way the orbit and rotation work together, on Mercury, a day is actuallyalmost twice as long as a year.

There may also be ice on the

top and bottom of Mercury.

Like the Earth, these areas

(called poles) don't get much

warmth from the Sun. Any ice

there won't melt.

It is very hot during the day

(over 400C) because Mercury

is so close to the Sun. At night it

is very cold because Mercury

loses almost all its heat since

there is almost no atmosphere

to keep the warmth there. The

temperature can fall to almost

-175C.


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Our Solar System


What is Mercury made of?

The centre of Mercury is made of iron in partly-molten (liquid) form. We know that

it is iron at the centre because the planet generates a magnetic field. It contains

more iron for its size than any other planet in the Solar System. The rest of

Mercury, its thick crust, is made of a special type of rock called silicate rocks

.There are craters near the poles that are constantly in shadow. Some of these

craters contain ice. There is a huge crater on Mercury called Caloris Basin. It was

formed when a comet hit the planet and lava or molten rock filled the impact

crater. The round wall of this crater is over 2km tall.

How much would Mercury's gravity pull on me?

If you were on Mercury, it would pull you down less than half (38%) as much as

the Earth. An item that weighs 100 Newton on Earth, would only weigh 38

Newton on Mercury.

Who is this planet named after?

In Roman mythology, Mercury was the messenger of the gods. He wore a hat

and sandals with wings on them, allowing him to travel around the world very

quickly. The planet Mercury was named after him because it moves around the

Sun faster than any other planet in the Solar System. It moves nearly 48 km every

second!

A planet is a large space object which revolves around a star. It also reflects that star's light. Eightplanets have been discovered in our solar system. Mercury, Venus, Earth, and Mars are the planets

closest to the Sun. They are called the inner planets. The inner planets are made up mostly of rock.

The outer planets are Jupiter, Saturn, Uranus, and Neptune. Jupiter, Saturn, Uranus, and Neptune

are large balls of gases with rings around them. All eight planets travel around the Sun in a

different orbit. In its orbit, there are not many other objects like the planet.

Dwarf planets are objects that are similar to planets except that they orbit the Sun in areas where

there are many similar objects.

The Inner Planets The Outer Planets Dwarf Planets

Mercury Jupiter Pluto

Venus Saturn Ceres

Earth Uranus Eris

Mars Neptune Haumea

Makemake


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Mercury is the smallest planet in our solar system. Mercury is

about the same size as our Moon. It is very close to the Sun.Mercury travels around the Sun faster than any other planet.

That is how it got its name. It was named after Mercury, the

swift messenger of the gods in ancient Roman mythology.

Mercury can only be seen from Earth just before sunrise or

just after sunset, but not in the middle of the night. That is

because Mercury always appears near the Sun when viewedfrom Earth. Mercury has a very thin atmosphere. Humans

would not be able to live there. The surface of Mercury has

holes in it where objects such as meteorites and asteroids

crashed into it.

TheTheTheThe temperature on Mercury getstemperature on Mercury getstemperature on Mercury getstemperature on Mercury gets so hot it could melt a tinso hot it could melt a tinso hot it could melt a tinso hot it could melt a tinpan.pan.pan.pan.

Mercury can be seen by people on earth just before sunriseMercury can be seen by people on earth just before sunriseMercury can be seen by people on earth just before sunriseMercury can be seen by people on earth just before sunriseor just after sunset on some clear nights.or just after sunset on some clear nights.or just after sunset on some clear nights.or just after sunset on some clear nights.


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Fact Sheet


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What is Mercury?

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How big is Mercury?

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What is Mercury's surface like?

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How long is a day on this planet?

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How long is a year on Mercury?

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What is Mercury made of?

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How much would Mercury's gravity pull on me?

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Who is this planet named after?

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Our Solar System Mercury