12. Beyond Earth
Answers to in-text questions, activities and Let us enhance our learning. NCERT Curiosity, Class 6 Science (CBSE).
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In-text Questions
Join some stars with lines to make a shape like an animal or an object. Give it a name and make up a story.
No. Everyone’s patterns, names and stories are different.
The patterns help us recognise stars in the sky. Long ago, sailors and travellers used them to find directions. They are still used as a backup in emergencies.
The Sun is the star closest to us. After the Sun, the nearest star is Proxima Centauri.
The Sun is much closer to us than other stars. So it looks big. Other stars are very far away, so they look like points.
In the daytime, the Sun is extremely bright. So we cannot see other stars.
Stars appear to twinkle a lot. Planets do not twinkle much.
We can see them with a pair of binoculars or a telescope.
Yes. Objects that move around planets are called satellites. Moons are natural satellites. The Earth has one Moon and Mars has two moons.
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Look at the two stars at the end of the Big Dipper’s cup. Imagine a line through them towards the north.
At about five times the distance between these two stars, the line leads to a star that is not very bright. This is the Pole Star.
First find three bright stars in a short straight line. They are the belt of Orion.
Imagine a line through these three stars towards the east. It leads to Sirius, the brightest star in the night sky.
There are many other galaxies beyond the Milky Way.
We do not know yet. Scientists are searching for life on exoplanets but have not found any evidence so far.
Let us enhance our learning
| Column I | Column II |
|---|---|
| (i) Satellite of Earth | (d) Moon |
| (ii) Red planet | (c) Mars |
| (iii) Constellation | (a) Orion |
| (iv) Planet commonly called an evening star | (b) Venus |
(i) M (in MAN, not in CAN), A (in ACE and FAN), R (in RAT, not in CAT), S (in SUN, not in FUN). The planet is MARS.
(ii) Riddle 1: My first letter is in VAN but not in CAN. My second is in PEN and also in TEN. My third is in NET but not in SET. My fourth is in SUN but not in SIN. My fifth is in SAT but not in CAT. I am the brightest planet. — VENUS
Riddle 2: My first letter is in BEE but not in BAT. My second is in CAT and also in MAP. My third is in RUN but not in SUN. My fourth is in TOP but not in MOP. My fifth is in HAT but not in CAT. I am the Blue Planet. — EARTH
(i) Sirius — it is a star far outside the Solar System.
(ii) Pluto — it is now called a dwarf planet.
Sirius is brighter. It is the brightest star in the night sky. The Pole Star is not very bright.
No. In the figure, Earth and Venus are interchanged. Saturn and Uranus are also interchanged.
Correct order: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune
The two end stars of the Big Dipper’s cup point towards the Pole Star, which is the end star of the Little Dipper’s handle. (Not to scale.)
The Big Dipper has seven bright stars — four form a cup and three form a handle. The Little Dipper looks similar but is smaller and dimmer.
Join the two end stars of the Big Dipper’s cup and extend the line. It reaches the Pole Star, the last star in the handle of the Little Dipper.
- Find the three stars in a short straight line in the middle. Join them — this is the belt.
- Join the four bright stars around the belt — two above (shoulders) and two below (knees).
- Extend the line of the belt. It leads to the very bright star on the left. Label it Sirius.
The stars are in the sky during the day also. But the Sun is extremely bright and lights up the whole sky. So the faint stars cannot be seen.
At dusk the Sun sets and the sky becomes dark, so stars appear. At dawn the sky becomes bright, so stars fade away.
Yes. The Big Dipper appears to move in a circle around the Pole Star. The Pole Star stays nearly at the same place.
This happens because the Earth rotates.
In your sketch, draw the Pole Star in the centre. Draw the Big Dipper at 8 pm, 10 pm and 12 midnight at different positions around it, and write the time near each.
The Night Sky
When the Sun goes down and the sky turns black,
The stars come out and twinkle back.
The Big Dipper shows me where to go,
The Pole Star shines in the north, soft and low.
Orion stands with his belt so bright,
And Sirius sparkles through the night.
The Moon looks down with a gentle smile,
Come, let us watch the sky a while!