Which hemisphere has the most water, the northern or the southern hemisphere?
DISTANCE
FROM SUN:
93 million miles
REVOLUTION AROUND SUN: 365 days
ROTATION: 24 hours
DIAMETER: 7,900 miles
AVERAGE TEMPERATURE: 60°F
SATELLITES: 1
Earth, our home planet, is a beautiful blue and white ball when seen from space. The third planet from the sun, it is the largest of the inner rocky planets, just a little larger than Venus. Earth is the only planet known to support life and to have liquid water at the surface.
Earth's average temperature is about 60 degrees
Fahrenheit. That sounds pretty comfortable, but scientists are worried that the
temperature is rising because of global warming. Certain gases that
are in the Earth's atmosphere trap the sun's heat and keep the Earth
warm. This is called "the greenhouse effect." Usually, this is a
good thing, but some of these gases seem to be building up in the atmosphere,
which could make the Earth get too warm.
What do you think the term "greenhouse effect"
means?
What could happen if the Earth got
too warm? Try to think of obvious and not-so-obvious
results.
The
Earth has an atmosphere that is made up mostly of nitrogen and oxygen, but there
are other gases, too. The atmosphere gives us air to
breathe. The atmosphere also shields us from nearly all of the
harmful radiation coming from the sun and other stars. It protects us from
meteors, most of which burn up in the atmosphere before they can strike the surface.
Give 3 reasons our atmosphere is very important.
Because the Earth spins so fast and has a center core of liquid nickel and iron, it has a strong magnetic field. Our planet's rapid spin and molten nickel-iron core create a strong magnetic field. This also helps to protect us from radiation.
The Earth orbits
around the Sun. The orbit is elliptical. It takes one year to go around the
sun one complete
time. The Earth also rotates,
or spins, on its axis.
It takes one day to spin around one complete time. The Earth's axis is
not straight up and down, but tilted a little bit. This tilt causes us
to have seasons and unequal day and night. If the axis were not tilted, the
temperature where you live would hardly ever change.
We mark time on Earth by
what is happening in the heavens.
An Earth year = one
complete orbit (revolution) of the Earth around the sun. How many days
does it take the Earth to orbit the sun?
An Earth day = one complete
rotation of the Earth on its axis. How many hours does it take the Earth
to spin one time on its axis?
Did you know that.....????
Almost 75% of the Earth's surface
is covered by water. That is almost 3/4 of the Earth!
Which fraction below shows 3/4?
Which hemisphere has the most water, the northern or the southern hemisphere?