Planetary Science Honor

Nature Study

Requirements

  1. Have the Astronomy Honor.
  2. What are the three units of astronomical distance measurement classically used?

    Answer: The three classic units are: the Astronomical Unit (AU) — the average distance from Earth to the Sun (about 150 million km), used within the solar system; the light-year — the distance that light travels in one year (about 9.46 trillion km), used for stars and galaxies; and the parsec (about 3.26 light-years), used in parallax measurements. — Each unit serves a scale: AU for the solar system; light-year and parsec for the distances between stars and galaxies.

  3. What is the name and size of the galaxy we live in? What is the galaxy closest to ours?

    Answer: We live in the Milky Way galaxy, a spiral galaxy with a diameter of about 100,000 light-years and more than 100 billion stars. The nearest large galaxy is Andromeda (M31), about 2.5 million light-years away — although satellite galaxies, such as the Magellanic Clouds, are much closer. — The Milky Way is our 'city of stars'; Andromeda is the great neighbor with which it is one day expected to merge.

  4. What is a cosmic cloud and what is its relation to the formation of new stars and planets?

    Answer: A cosmic cloud (nebula) is a large cloud of gas (mainly hydrogen) and dust in space. Under the action of gravity, it contracts and heats up; the dense center forms a new star, and the disk of gas and dust left over around it gives rise to the planets. This is why nebulae are called 'star nurseries'. — Stars and planets are born from the collapse of these clouds of gas and dust — the raw material of the universe.

  5. What is the Oort cloud?

    Answer: The Oort cloud is an immense spherical region of icy bodies that surrounds the solar system, far beyond Pluto's orbit, at its most distant boundaries. It is believed to be the origin of long-period comets, which are occasionally launched toward the Sun. — The Oort Cloud is the icy frontier of the solar system and the reservoir from which many comets originate.

  6. Give the following characteristics of the planets of the solar system:
    • Sidereal revolution;
    • Relative gravity;
    • Number of moons.

    Answer: 1) Sidereal revolution (time to complete one full orbit around the Sun): Mercury about 88 days; Venus about 225 days; Earth about 365 days; Mars about 687 days; Jupiter about 12 years; Saturn about 29 years; Uranus about 84 years; Neptune about 165 years. 2) Relative gravity (taking Earth = 1.00): Mercury about 0.38; Venus about 0.90; Earth 1.00; Mars about 0.38; Jupiter about 2.5; Saturn about 1.07; Uranus about 0.90; Neptune about 1.14. 3) Number of moons: Mercury 0 moons; Venus 0 moons; Earth 1 moon; Mars 2 moons; Jupiter more than 90 moons; Saturn more than 140 moons; Uranus about 28 moons; Neptune about 16 moons. — Comparing period, gravity, and moons shows how unique each planet is — from the small and fast ones (Mercury) to the slow giants full of moons (Jupiter and Saturn).

  7. What is the importance of meteorites for the study of the universe?

    Answer: Meteorites are 'free' samples from space that reach Earth. Since many come from the early solar system and have barely changed, they allow us to study the composition and age of celestial bodies, understand how the planets formed, and even obtain information about asteroids, the Moon, and Mars — without having to travel there. — Studying meteorites is like reading pages of the history of the solar system that have fallen into our backyard.

  8. Using a telescope (which can be homemade or built from a kit), observe the night sky and identify the visible planets.