Adventist Youth Honors Answer Book/Nature/Stars (South Pacific Division)

Stars (South Pacific Division)
Nature South Pacific Division	Skill Level 1
	Year of Introduction: 2001

Contents

1

a) Name the closest star beyond the solar system.

Alpha Centuri the brightest of the Pointers in the Southern Cross. This star is actually comprised of three stars. Two are bright blue stars that move around each other. The third is a red dwarf that revolves around the other two. The red stars name is Proxima Centuri and at present is the closest.

b) Compare the distance from the earth of this star with the distance of the moon to the earth.

Closest Star: 4.243 light years

Moon: 386,000 km

c) What governs the tide?

The tides are governed by the Moon, and to a lesser extent, by the Sun. Spring tides are when the pull of the moon and sun is greatest and neap tides is when the pull is least.

d) What causes an eclipse?

An eclipse is caused when the Sun, Earth, and Moon are in a direct line with one another. When the Earth is between the Sun and the Moon, we see a lunar eclipse, which is the Earth's shadow falling on the moon. When the Moon is between the Sun and the Earth, we see a solar eclipse, which is when the Moon's shadow falls on the Earth (blocking the Sun).

e) What is a shooting star?

A shooting star is not a star at all, but rather a meteor. A meteor is any celestial body (usually quite small) that falls to the Earth. Most burn up in the atmosphere before reaching the surface, leaving a bright, short-lived streak in the sky. A meteorite is the fragment that reaches earths surface sometimes creating a crater..

f) How fast does light travel?

300,000 km per second. So the distance in a year is called a light year.

2

Make a diagram showing relative positions and movements of the earth, sun, and moon. Show positions and movements for eclipses of the sun and moon.

One may demonstrate by using an orange, walnut, and marble, or similar objects, to show positions and movements of the earth, sun, and moon when there is an eclipse of the sun and when there is an eclipse of the moon. Then draw simplw diagrammes.

Place the "sun" model in the center. Place the "earth" some distance from the sun, and show how it travels in a near circle around the sun. The moon travels around the earth, but it always shows the same face to the earth (it's rotation on its axis takes the same amount of time as its orbit around the earth.)

Lunar eclipse

Solar eclipse

3

Make a diagram of our solar system and be able to name the planets in order from the sun

Solar System diagram showing the relative sizes of the planets (plus Pluto, a dwarf planet)

The planets in our solar system, starting from the Sun, are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune. Pluto was also considered a planet from 1930 until 2006 when the International Astronomer's Union (IAU) was prompted by the discovery Eris, a body larger than Pluto, to come up with a formal definition of the word "planet." For years leading up to this announcement there had been rumblings in the scientific community that classifying Pluto as a planet had been a mistake, much as the classification of Ceres, the largest asteroid had been a mistake in the 1800's. After the discovery of Ceres, more and more asteroids were discovered, and it became increasingly clear that it was not a planet. The same thing began to happen in the late 1900's when astronomers began to discover several Pluto-like objects in the Kuiper belt. The debate came to a head with the discovery of Eris, which has a diameter that exceeds Pluto's by 70 miles (110 km). The IAU would have to either recognize Eris as the tenth planet or "demote" Pluto. The demotion of Pluto, though not popular with the general public, makes the most scientific sense and demonstrates that science is capable of correcting its errors.

The new definition of a planet requires that an object a) orbit a star (such as the Sun), b) not orbit another planet (such as a satellite), and c) dominate the vicinity of its orbit. Pluto did not make the cut because its orbit is dominated by Neptune, and there are many objects orbiting in its vicinity that Pluto has no effect upon.

There are a number of mnemonic phrases that are easily memorized for remembering the names of the planets, including "My Very Energetic Mother Just Served Us Noodles.

4

What is the difference between planets and fixed stars? Identify in the sky eight fixed stars.

The word planet means wanderer because the planets appear to wander about the sky relative to the stars. The fixed stars do not move in relation to one another (although they all appear to move together because of the Earth's rotation on its axis).

Which eight stars you choose to teach your Pathfinders to identify will depend on the season (spring, summer, winter, or autumn), although some stars are visible year-round.

Alpha Centauri, Beta Centauri (pointers in Southern cross), Canopus (Argo), Sirius (Canus Major), Aldebaran (Taurus), Castor, Pollux (Gemini), Rigel, Betelguse (Orion), Antares (Scorpio).

5

What is a constellation? Name and point out six. Name two constellations visible throughout the year.

A constellation is a pattern of stars that look grouped together. The ancient Greeks gave them names and made up myths about them. By naming constellations they made a map of the sky.

Southern Cross or Crux Australus, Orion, Virgo, Centaur, Scorpio, False Cross, Canis Major, Leo. Different constellations are visible in different seasons.

Part of the Southern Cross are on the following countries flags: Australia, Brazil, New Zealand, Niue, Papua New Guinea, Samoa, Tokelau

What two constellations are visible throughout the year? Southern Cirumpolar Constellations.

Southern Cross, False Cross, Triangulum Australe, Apus, Centaurus, Musca, Diamond Cross, Carina.

6

For the Northern Hemisphere: draw a chart of the Big Dipper, Cassiopeia, and the North Star. For the Southern Hemisphere: draw a chart of the Southern Cross, Orion and Scorpio.

A series of charts is needed because the constellations are sometimes far apart.

Note 1. The Southern Cross constellation is a mix of a complete constellation Crux (cross) and the pointers from the constellation Centauri.

Note 2. Orion the hunter. In the Northern Hemisphere this is an upright hunter but in the Southern Hemisphere the hunter is up side down so is commonly referred to as The Pot or in some parts of Australasia The Saucepan

Note 3. Scorpio is also upside down in the Southern Hemisphere. Most times it is viewed perpendicular to the horizon.

A chart of constellation Orion

Crux chart part of the Southern Cross

Scorpio constellation

For the Northern Hemisphere constellations refer to the GC version of the Star Honour.

7

What is the Milky Way? Observe the Milky Way in the night sky.

The Milky Way is the name of our galaxy. A galaxy is a disc of stars, and since the Earth and the rest of our Solar System are in that disc, the Milky Way appears as a faint strip in the sky. To view it properly, you will need a very dark sky.

8

What is the morning and evening star? Why does it carry both names?

The morning star and evening star are one and the same body - the planet Venus.

Because it is nearer to the Sun than the Earth is, it always appears in the sky near the Sun. This means it can only be seen either in the morning within a few hours of sunrise, or in the evening within a few hours of sunset. Venus is the third brightest object in the sky, after the Sun and the Moon, so it is fairly easy to spot. When it appears in the evening, it will always be in the West. When it appears in the morning, it will always be in the East. You may need to consult an almanac to know whether it will appear in the morning or in the evening.

9

Explain zenith and nadir

Zenith is the point directly above a location.

Nadir is the opposite of Zenith. It is the direction that gravity pulls from a location.

10

What is the Aurora Australis? What causes it?

An Aurora is a beautiful natural phenomenon that often occurs near the polar regions of Earth.

The immediate causes of aurora are precipitating energetic particles from the Sun. These particles are electrons and protons that are energized in the near geospace environment. This energization process draws its energy from the interaction of the Earth's magnetosphere with the solar wind.

Notes

The requirements for this honour were updated by the South Pacific Division in 2013, and those changes are reflected here.

References

This version the latest from the SPD uses information from the previous. Edited by Geoff Harvey. Invercargill Pathfinder Club.