The penguin that turns and walks in the opposite direction is walking southwards. This is because the South Pole is located at the southernmost point of the Earth, and any direction away from it would be towards the north.
Two reasons that indicate the Earth is spherical are:
1) The shape of the Earth's shadow during a lunar eclipse: When the Earth passes between the Sun and the Moon, it casts a curved shadow on the Moon. This curved shape indicates that the Earth is spherical.
2) The way ships disappear over the horizon: As a ship sails away from shore, it gradually disappears from view bottom-first. This happens because the Earth's surface curves away from the observer, making the ship disappear over the horizon.
To calculate the circumference of the Earth, we can use the formula: Circumference = π x Diameter.
Circumference = 3.14 x 13,000 km ≈ 40,840 km.
In winter, the sun appears more to the north and lower in the northern sky than in summer because the Earth is tilted on its axis. During the winter solstice, the northern hemisphere is tilted away from the sun, resulting in less direct sunlight and colder temperatures.
Solstice: A solstice occurs twice a year when the Sun reaches its highest or lowest point in the sky at noon, marked by the longest and shortest days of the year. The summer solstice is the longest day of the year, while the winter solstice is the shortest day of the year.
Equinox: An equinox occurs twice a year when the Sun is directly above the equator, resulting in equal day and night length. The spring equinox marks the beginning of spring, while the autumn equinox marks the beginning of autumn.
The "Land of the Midnight Sun" refers to regions near the Earth's poles, where the sun remains visible for 24 hours a day during certain parts of the year. This phenomenon occurs because of the tilt of the Earth's axis, causing the sun to remain above the horizon for extended periods of time.
The Earth's surface travels at different speeds at different latitudes due to the Earth's rotation. As we move away from the poles towards the equator, the rotational speed of the Earth increases. Therefore, in Darwin, which is closer to the equator, the Earth's surface is traveling faster (about 1500 km/h) compared to Melbourne, which is located at a higher latitude and travels at a slower speed (about 1000 km/h).
On planet Mercury, which is not tilted, the days and nights would each last for about 59 Earth days. The year on Mercury would be about 88 Earth days, as it takes that long for it to orbit the sun. The lack of tilt on Mercury would mean no variation in seasons.
The star trails in the photo appear as straight lines when pointed straight up at the equator because the stars appear to move in circles around the celestial poles. At the equator, the celestial poles are directly overhead, resulting in the stars appearing to move in straight lines as the Earth rotates.
Two penguins are standing at the South Pole.
One walks northwards, and the other turns and
walks in the opposite direction. What direction
is this? Explain.
How do we know that the Earth is spherical?
Give at least two reasons.
The diameter of the Earth is about 13 000 km.
Calculate its circumference.
In winter the sun is more to the north (lower in
the northern sky) than it is at the same time in
summer. Why is this?
Find out the meanings of the terms solstice and
equinox.
Where is the ‘Land of the Midnight Sun’? Why is
it called this?
In Darwin, the Earth’s surface is travelling at
about 1500 km/h. In Melbourne it is travelling at
only 1000 km/h. Why is this?
The planet Mercury is not tilted. It rotates slowly
on its axis once every 59 Earth days, and
revolves around the sun in 88 Earth days. What
would the days, nights, years and seasons be
like?
Look at the photo of the star trails.
If you were at the equator and pointed the camera straight up, the trails would
be straight lines. Try to explain this.
1 answer