The Inner Planets Part 1Mercury (5th grade)

The inner planets include Mercury, Venus, Earth, and Mars.

Mercury is the closest planet to the sun.

https://youtu.be/z8aBZZnv6y8

Watch this 2:41 video on the planets’orbits around the sun. Keep in mind that the scale is not accurate. The real scale is so large, it would be difficult to see each planet.

Which planet orbits the sun thefastest?

Question: Which planet revolves around the sun the fastest and why?

Answer:

Mercury’s orbit is the fastest because it’s the closest to the sun, so its orbital ring is much smaller than the other planets’.

https://youtu.be/f6foCDF6zI0

Here is another video of the planets’ orbits.Pay attention to how fast Mercuryrotates on its axis compared to Earth.

Also, pay attention to which directionVenus rotates.

Question: Which rotates faster...Earth or Mercury?

Question: How did Venus rotate compared to the other planets?

Answers:

Mercury rotates very slowly compared to Earth.

Venus rotates in the opposite direction of the other planets.

The sun rises in the West, if you’re on planet Venus!

Mercury

This picture of Mercury was taken by NASA's MESSENGER spacecraft.

Mercury hasno moons.

How Did Mercury Get Its Name?

The Romans believed that gods and goddesses were in charge of everything on Earth. Mercury is named after the messenger for their gods.

...The Roman god Mercury had wings on his helmet and shoes. He could travel very quickly from place to place to deliver messages. The planet Mercury moves quickly around the sun. That is how it got its name.

Mercury’s orbit takes the small planet as close as 29 million miles and as far as 43 million miles from the sun. This is because its orbit is not a perfect circle.

Mercury’s transit

The dots are Mercury, showing how it orbits in front of the sun from our viewpoint.

Mercury is the closest planet to the sun.

It is about 35.98 million miles from the sun.

If one could stand on the scorching surface of Mercury when it is at its closest point to the sun, the sun would appear more than three times as large as it does when viewed from Earth.

Computer generated picture ofMercury Earth

How Big Is Mercury?Mercury is a little bigger than Earth's moon. It is

made of heavier materials, like iron. If you could weigh Mercury and the moon, Mercury would weigh a lot more. Mercury is heavy, but it is small. It would take more than 18 Mercurys to be as big as Earth.

Moon Mercury

Mercury is largely made of iron (scientists believe). This planet is like a large metal ball of iron with a very thin silicate crust (think powdery sand).

iron

Silicates are minerals that are made ofsilicon and oxygen.

Mercury's core makes up about 75% of the planet. Its thin mantle is only about 300 to 400 miles thick. Next to Earth, Mercury is the second most dense planet in our Solar System.

How much would you weigh on Mercury? You would not weigh as much as you do on Earth because Mercury is smaller, and so has less gravity. If you weigh 70 pounds on Earth, you would weigh only about 27 pounds on Mercury.

You could leap like the astronauts did on the moon!

It takes Mercury 88 Earth days to make a complete orbit around

the sun.

Mercury’s year would end on Earth’s March 29th!

A day on Mercury lasts a lot longer

than a day on Earth. One day on Mercury lasts 59 Earth days.

The tilt of its axis is only 0.1 degrees.

Mercury is heavily cratered bymeteor impacts.

Photo taken from MESSENGER probe

Photo taken from MESSENGER probe

Mercury does not have much of an atmosphere. Therefore, it experiences

extreme temperature changes.

The side of Mercury experiencing night-time can be as cold as -290 0 F.

super coldsuper hot

The side that is in daylight can get to 8010 F. That’s hot enough to melt lead.

Even so, Mercury is NOT the hottest planet in the solar system! (Can you guess what it is?)

Did you guess correctly? Venus is the hottest. We’ll learn more

about Venus next time.

How do we know so much about Mercury?

In 1973, NASA launched the Mariner 10.

Mariner 10 was an unmanned probe that was designed to fly

by Venus and Mercury.

Mariner 10 was the first probe to ever visit Mercury. It reached Mercury in 1974 and did a fly-by, taking photographs.

31 years later, NASA launched the MESSENGER spacecraft. It was 2004.

https://youtu.be/RSYsHy5A2-w

Click the above link to watch a 2:05 min. video of the launch of the MESSENGER spacecraft.

The MESSENGER reached Mercury in 2008. It flew by Earth once, Venus twice, and Mercury 3 times. It was the 1st probe to actually orbit Mercury.

The MESSENGER spacecraft had many instruments to take measurements and photographs.

Its mission lasted 10 years. MESSENGER finally ran out of fuel in

2015 and crashed into Mercury, leaving a 50 foot crater on its surface.

Mercury is often called a morning star. This is because it shines brightly in the early morning just before the sun rises. It has also been called an evening star for the same reason. Mercury is often visible for a brief period of time just after the Sun sets.

Photograph of the moon, Mercury, and Venus.

Mercury

Okay, it’s time to quiz yourself:

How many moons does Mercury have?

Answer:

0 moons

Which is bigger...Mercury or Earth’s moon?

Answer:

Mercury is a little bigger.

Question:

What was the first probe to fly by Mercury and took the first

photos we have of this planet?

Answer:

Mariner 10. It reached Mercury in 1974.

Question:

What was the 2nd probe sent to Mercury and the only one to

actually orbit Mercury?

Answer:

The MESSENGER spacecraft, which reached Mercury in 2008.

Bonus Question:

Why do you think NASA named this probe the “MESSENGER”?

Answer:

It was named after the Roman god Mercury, who was the

messenger to the other gods.

Question:

How long does a Mercury year last?

Answer:

88 Earth days

Question:

How long is a Mercury day?

Answer:

59 Earth days

Question:

What is Mercury made of?

Answer:

Mostly iron (in its core), with a thin rocky layer as the crust.

Question:

Which planet has a greater tilt...Earth or Mercury?

Answer:

The End

This PowerPoint was created by Mrs. Burch