5(a). What is the angle of the ecliptic with respect to the celestial equator?
The angle of the ecliptic with the respect to the celestial equator is approximately 23.6 degree. It was measured by finding the intersection between the celestial equator marking and ecliptic marking, then zooming in to make these two marking straight, and finally measuring the angle of intersection by a protractor.
5(b). Explain why this ecliptic path exists.
Ecliptic is the apparent path of the Sun’s motion. Because the Earth is circling around the Sun, the path of the sun is observed as circular on Earth. This path stays relatively constant throughout years because the orbits of Earth and other planets in our galaxy lays on the ecliptic plane, which is defined by ecliptic path. Therefore, the constant existence of this path is the proof of heliocentric model of our solar system. Because the Sun is the center of our solar system, the constant ecliptic path exists.
5(c) How does this path change throughout the year? Why does this happen? Try to refer specifically to its declination.
The declination of ecliptic path fluctuates throughout each year. It has a periodic pattern. The sun’s declination in January is around -23 degrees. Then, the degree of declination starts to increase towards positive and reach 0 degree in the middle of March. It reaches the maximum declination of approximately +23 degrees in mid-June. The declination then starts to drop towards negative. It reaches 0 degree again in mid-September and finally returns to -23 degree as the time approaches to January. If this process is graphed with time at x-axis and declination at y-axis, the fluctuation within a year can be seen as a cycle of cosine function. This happens because the angle between the ecliptic and celestial equator is around 23 degrees. The Earth travels around sun on ecliptic plane, which is defined by ecliptic path. The ecliptic path has a 23.6°angle between celestial equator. Since the declination is measured from the celestial equator, the declination of the sun’s path observed from Earth should theoretically vary from -23.6° to +23.6°.
7(a) What planets are visible tonight at 10pm?
Viewing from Ottawa, with ground turned on in Stellarium, the only visible planet is Jupiter at 10pm.
8(a) What planets are near the sun right at 1300hr?
At 1300hr, Mercury and Venus are near the Sun.
8(b) Are there any planets that always appear near the sun? Explain.
Mercury and Venus always appear near the sun. Because the orbits of Mercury and Venus are relatively closer to the sun, their distance to the sun is shorter; thus, these two planets always appears near the Sun. Sometimes, other planets, such as Mars, appears to be near the Sun as well, yet the frequency is low due to the distance difference.
10(a). What phase is the Moon in?
The moon is only visible around 2am tonight, and only left-half of the Moon is visible. Therefore, the Moon is in “Waning Gibbous” phase.
12(a) How many moons...