How can you prove the
earth is round?
AMY, AGE 9, BRACKNELL
Answer: There are a few things you could do to
prove the Earth is round. The easiest is to go to the seaside and watch
a boat disappear out to Sea.
As it goes, you will notice that it slowly disappears
and seems to sink into the horizon. The same is seen if you are on a boat
and watch buildings on the shore as you sail out. Another way is to watch
a lunar eclipse.
The shadow of the Earth is seen on the Moon during the
eclipse and shows us its shape.
Rocket flying over Mars |
If a rocket exploded in space, how far away would
you hear the blast?
CHEE MIN LO, AGE 13, TAIPEI, TAIWAN
Answer: If a rocket explodes in space, even if
you stood very close to it, you would hear nothing!
For sound to travel, it needs something to travel through.
Since the vacuum of space is empty there is nothing for it to travel through.
You would see the explosion and feel it but would hear nothing.
Could you please tell me how you could make gravity
if you wanted to grow plants on a planet like mars?
DENISE, AGE 10, AUSTRALIA
Answer: Plants do not need gravity to grow! This
has been shown when they have been grown on board the space craft in orbit
around the Earth.
Because of the way space craft orbit Earth, to anyone
or anything on board, it feels like they have no gravity and plants grow
just fine.
Is the Earth the only terrestrial planet to experience
total solar eclipses?
ROBI, AGE 12, USA
Answer: Yes is the short answer to this question.
To see any type of solar eclipse, the planet in question must have a moon.
Mercury and Venus have no moons so they do not get any
type of eclipse. Mars has two moons but they are too small to completely
eclipse the Sun from view in the Martian sky.
Of the four terrestrial planets, Earth is the only one
to experience total solar eclipses.
How many miles are there in a light year?
ANON
Answer: A light year is a measure of distance
and tells us how far light can travel in one year. Astronomers use this
as a measure of distance instead of miles or km because the numbers would
be too big. One light year is equal to 5.8 million million miles or 9.4
million million km.
Andromeda |
I've read that the Andromeda Galaxy and our galaxy
are slowly being pulled together. What will happen when the two galaxies
finally collide?
NATALIE, AGE 16, NORFOLK
Answer: It is true that the Andromeda Galaxy is
heading for our own galaxy the Milky Way. However don't panic. It's going
to happen in about 3 billion years time.
When it does happen, there won't be a huge bang because
galaxies are made up of billions of stars and a lot of empty space.
Instead the galaxies will just flow through each other.
As they do, their gravity is likely to cause a burst of star formation
but that's about it.
Could we ever achieve light speed?
SAM, AGE 12, BETTWS
Answer: I think I am safe in saying no to that
question. You may have heard of a scientist called Einstein. He found
that the faster you travel, the heavier you get.
When you reach the speed of light you are infinitely
heavy. It's not possible to measure how heavy because there are not enough
numbers to explain it! So as you get nearer and nearer to light speed
it gets harder and harder to make you go faster.
It may be possible to get to a speed faster than light
but you would somehow have to do it without going at the speed of light
on the way!
How long would it take a radio message to get from
the Moon to the Earth?
AMBER, KCMO
Answer: Radio signals travel at the same speed
as light signals. It would take 1.3 seconds to get a radio (or light)
signal from the Moon to the Earth.
Sputnik, a Russian satellite |
What was the first object launched into space?
ALEX, AGE 12, DOWNHAM MARKET
Answer: The first man made object sent into orbit
around the Earth was a Russian satellite called Sputnik 1 which was launched
in 1957 and returned back to Earth about a year later.
In space there are nine planets. Do you think there
are other solar systems with more planets than we have?
JAZ TALBOT, AGE 11, SOUTH LONDON
Answer: We know
that there are definitely other stars out there with planets around them
but we have not yet found any with more planets than our own. This is
probably because the telescopes aren't accurate enough yet to see them
all.
What is an astronomical unit?
DANNIELLE, AGE 12, DUNDEE
Answer: An astronomical unit is a measure of distance
that astronomers use. It's based on the average distance between the Earth
and the Sun.
This works out to be 150 million kilometres. The average
distance to Pluto is 5.5 thousand million km but it's much easier to easier
to deal with when you change it into astronomical units.
Using this scale, Pluto is 38 astronomical units away.
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