Answers To Astronomy Questions In This Essay.

(a) What is the Ecliptic?

(b) The ecliptic plane intersects the celestial equator plane at an angle of approximately 23 degrees. Explain how this fact causes the seasons on Earth.

(a) Can the crescent moon be high above your head at midnight? Explain your answer.

(b) Why isn’t there a lunar eclipse every 28 days?

(a) The density of all Earth rocks is approximately 3000 kg/m3. The average density of the entire Earth is higher: 5500 kg/m3. Why does this explain the presence of a metal core at the heart of the Earth?

(b) Give one reason why we think that part of Earth’s core is liquid.

(a) Explain how the green house effect works on Earth.

(b) Explain one of the reasons why the green house effect on Venus became so strong.

Volcanos exist on Earth, Venus and Mars, though on Mars there is likely no active volcano today. On Earth we have volcanos at plate boundaries as well as in the middle of plates (shield volcanos), while on Mars and Venus we only have shield volcanos. Explain why that is the case.

(a) List two key pieces of evidence that liquid water once flowed on Mars.

(b) Can liquid water exist on the Martian surface today? Explain your answer.

Both Jupiter and Saturn emit more energy into space than that expected due to heating from the Sun. What is/are thought to be the source/s of the extra energy?

Both Jupiter and Saturn are not perfectly spherical, with both exhibiting a degree of oblateness.

(a) Why? Explain your answer. (b) Given their respective masses, what does the degree of oblateness infer about the relative sizes of the cores of the two planets?

Explain why Saturn's F-ring is confined to such a narrow band.

Neptune and Uranus both appear bluish in colour. Why is this?

What is the Ecliptic and how does it affect the seasons on Earth?

1A. It basically refers to the apparent path of the sun around the sky. The term eclipticis used to describe the circular path that the sun appears o follow within the course of the year. It is the circular path on the celestial sphere. It is the basis of the ecliptic coordinate system. This is also marks the annual path of the sun. It is the projection of the orbit of the Earth onto the celestial sphere.

1B.The seasons are usually caused due to the tilt of the rotational axis of the earth. The axis tilts away or towards the sun as in the course of its yearlong travel around the sun (Krisha et al2016).

2B. A lunar eclipse is usually caused when the Moon enters the shadow of the earth. This does not happen every month or after every twenty eight days because the orbit of the Earth around the sun is not the same plane in accordance to the orbit of the Moon around the Earth. Only at the time when the Moon is crossing the plane of the orbit of the Earth, the lunar eclipse can occur.

3A. As a general rule, metal have a higher density than rocks, so since the average density of all rocks is approximately 3000kg meter cube and that of the Earth is 5000 meter cube. This indicates a large metallic mass present inside the earth (Srivastava et al 2015). This metallic mass would also explain the cause the Earth’s magnetic field. Hence, from this it is apparent that the Earth contains a metallic B. It is because the temperature inside the earth increases at a rate of one degree centigrade for every 32m in depth. So, at the core which is the inner most layer of the earth, the temperature will be high enough to melt rocks. However, the core consists of molten material and is not exactly liquid in nature due to the tremendous pressure exerted by the overlying layers.

4A.The rays of the sun enter the earth and cannot escape due to the concentration of several gases like carbon dioxide and chloro fluro carbons. The constant concentration of these sun rays within the surface of the earth makes the earth warmer and also habitable. However it is seen in the present day scenario that due to large scale pollution, there is an increased amount if gases like carbon dioxide and other pollutants within the earth’s atmosphere, as a result of which, the sun rays can no longer escape the atmosphere of the earth and increases the earth temperature to a great extent, this causes the greenhouse effect.

Can a crescent moon be high above your head at midnight and why isn't there a lunar eclipse every 28 days?

4B.This greenhouse effect is particularly very strong in Venus because the planet Venus is very similar to that of the Earth in terms of its mass and size but at the same time the temperature of the surface of the planet Venus is about 460 degrees Celsius. This is very hot and can even melt a metal like lead. The atmosphere of Venus comprises of very large amount of carbon dioxide gas. This naturally has contributed in strengthening the greenhouse effect (Robitaille et al 2013).

5. Mars and Venus, acidic lava is nonexistent and basic lava forms shield volcanoes. As a result of this, there are only shield volcanoes found in these planets. Due to the absent of acidic lava, they do not have the conical volcanoes. However, in earth, there are both acidic and basic lava as well; therefore one can find both shield as well as conical volcanoes (Fredericks et al2014).

6A.Some signs show that there are same traces of water being found on Mars. One is the detection of hydrated salts in the slopes of the planet. Water plays a major role in forming the hydrated salts. As these salts are found in the slopes of the planet, it means that there must have been the traces of water in the planet mars. Evidence is that there is the trace of frozen water lying below the surface of the planet. This has given rise to the formation of strange layered craters, which further confirms the fact that there must have been presence of water on the surface of mars.

6B.In today’s scenario, it is tough or liquid water to exist on mars. Most of the water found is in the state of ice. Some quantities of water exist in the form of vapor in the atmosphere of the planet. But as this planet is devoid of both hydrogen and oxygen, water to exist in liquid sate becomes quite unlikely (Shiggavi and Vallado  2015).

7. Both Jupiter and Saturn emit more energy in the atmosphere because they have a huge amount of gases stored in them that heats up the temperature within the planets itself. It is also because of the extra surface area that reflects a more amount of energy.

8. Both Saturn and Jupiter are thick in the middle. As they spin, they bulge around the equator. Along the line of the equator, there is a circle formed between the north and the south poles, gravity is holding the edge. However Saturn and Jupiter are really huge and gravity still manages to hold them together. This is why there is a bulge in the middle and they appear oblate.Saturn is 10.7% thicker around the middle. Jupiter is 6.9% thicker around the middle.

9. The f rings are very narrow, perhaps the narrowest among all the other rings of the Planet Mars. It is made up of strings or strands that are intertwined with each other. There are two moons one inside and the other outside the rings of Saturn. These are called the shepherding moon and it is because of the gravitational pull of these moons that keep the f ring concentrated to kits narrow width.

10. The bluish color of planet Neptune is mainly because of its cloud tops. The upper atmosphere comprises of eighty percent of hydrogen, nineteen percent of helium and a mere trace of one percent of methane and other ices like ammonia and water.  It is this methane gas that absorbs the red ends of the colour spectrum. As a result of this, when the sunlight bounces back to the eyes, it appears blue.

References

Fredericks, A.C., Bartlett, J.L., Bell, S. and Stapleton, J.C., 2014, January. On-line Eclipse Resources from the US Naval Observatory: Planning Ahead for April 2024. In American Astronomical Society Meeting Abstracts# 223 (Vol. 223).

Knutson, H.A., Benneke, B., Deming, D. and Homeier, D., 2014. A featureless transmission spectrum for the Neptune-mass exoplanet GJ 436b. arXiv preprint arXiv:1401.3350.

Krishna, R., Anil, M.K., Neethu Raj, P. and Santhosh, B., 2016. Seed production and growth of Neopomacentrus cyanomos (Bleeker, 1856) in captivity. Indian Journal of Fisheries, 61(3), pp.50-56.

Lupisella, M., 2015. Life, intelligence, and the pursuit of value in cosmic evolution. The Impact of Discovering Life Beyond Earth. Murphy, T.W., McMillan, R.J., Johnson, N.H. and Goodrow, S.D., 2014. Lunar eclipse observations reveal anomalous thermal performance of Apollo reflectors. Icarus, 231, pp.183-192.

Robitaille, T.P., Tollerud, E.J., Greenfield, P., Droettboom, M., Bray, E., Aldcroft, T., Davis, M., Ginsburg, A., Price-Whelan, A.M., Kerzendorf, W.E. and Conley, A., 2013. Astropy: A community Python package for astronomy. Astronomy & Astrophysics, 558, p.A33.

Srivastava, V.K., Kumar, J., Kulshrestha, S., Srivastava, A., Bhaskar, M.K., Kushvah, B.S., Shiggavi, P. and Vallado, D.A., 2015. Lunar shadow eclipse prediction models for the Earth orbiting spacecraft: Comparison and application to LEO and GEO spacecrafts. Acta Astronautica, 110, pp.206-213.