This table gives data about some of the planets. You will need thisinformation to answer questions 1, 2 and 3.

Planet / Distance from Sun in millions of kilometres / Time to orbit the Sun in Earth years
Earth / 150 / 1
Mercury / 60 / 0.25
Mars / 230 / 1.9
Pluto / 5900 / 248
Jupiter / 780 / 12
Saturn / 1400 / 29

HELP

1Copy and complete these sentences.

aThe planet furthest from the Sun is .

bThe planet nearest to the Sun is .

cMars is colder than Earth because ...

dSaturn takes longer to orbit the Sun than Mars because...

eMercury takes the least time to orbit the Sun because...

CORE

2aUse the data in the table to plot a line graph of the distancefrom the Sun (horizontal) against the time to orbit the Sun(vertical) for the planets Mercury, Earth, Mars and Jupiter.Do not include Saturn or Pluto on your graph.

bIf Venus has an orbit time of 0.6 Earth years, approximatelyhow far is it from the Sun?

cImagine that astronomers have discovered a new planet,between Mars and Jupiter, which is 500 million kilometres fromthe Sun. Use your graph to estimate how long it would take forthe new planet to orbit the Sun once.

© Harcourt Education Ltd 2003 Catalyst 1

This worksheet may have been altered from the original on the CD-ROM.

EXTENSION

3The diagram shows the relative positions of the Earth, Mercury and Mars around the Sun, on 1July. Copy the diagram and use the table of data on Sheet 1.

aiMark an X on the diagram where the Earth would be six months later.

iiMark a Y on the diagram where Mercury would be six months later.

iiiMark a Z on the diagram where Mars would be six months later.

bExplain why, six months after the starting point, it would no longer be possible to see Mercury in the night sky.

cExplain why, six months after the starting point, Mars could still be seen from Earth but in a different part of the night sky.

4aThe table shows the length of time between each appearance of some comets that can sometimes be seen fairly easily from the Earth.

Comet / Time betweenappearances (years) / Last appearance
Halley / 76 / 1986
Hale-Bopp / 4000 / 1997
Kahoutek / 6 / 1997
Hyakutake / 65 000 / 1997
Temple-Tuttle / 33 / 1998

iWhat is a comet?

iiWhich of the comets listed has the largest orbit and how do you know?

iiiWhen will Halley’s comet next be easily visible from the Earth?

ivWhich of the comets will be the next one to come close to the Earth?

bMost meteorites that fall towards the Earth burn up in the atmosphere. They are often called ‘shooting stars’. The Moon’s surface is covered with craters caused by meteorites regularly hitting its surface. What does that tell you about the Moon?

© Harcourt Education Ltd 2003 Catalyst 1

This worksheet may have been altered from the original on the CD-ROM.