Sun and Stars Quiz

Sun and Stars

• The sun is composed primarily of hydrogen (73%) and helium (25%), with smaller amounts of heavier elements.
• It is estimated to be 4.5 billion years old.
• The sun emits heat and light energy through radiation.
• Astronomers determined the sun's mass (2 x 10³⁰ kg) using Newton's law of gravity and planetary orbits.
• The sun has six layers: Corona, Chromosphere, Photosphere, Convective zone, Radiative zone, and Core.
• A constellation is a group of stars that appear to be in a recognizable pattern from Earth.
• Stars vary greatly in size, distance, and brightness.
• A nebula is a large cloud of gas and dust, a crucial stage in star formation.

Stars: Life Cycle

• Protostars form from nebulae condensing under gravity.
• Protostars contract, increasing temperature and pressure, leading to nuclear fusion (hydrogen nuclei fusing to form helium).
• This fusion process powers the star, creating a main sequence star.
• Small/medium stars evolve into red giants, increasing size significantly.
• Then the red giant sheds outer layers forming a planetary nebula, while the core condenses into a white dwarf.
• Massive stars become red supergiants, which undergo further nuclear fusion and become extremely luminous.
• Finally, red supergiants explode in a supernova, potentially leaving behind a neutron star or black hole.

Solar System

• Inner planets (Mercury, Venus, Earth, Mars) are rocky with solid surfaces.
• Outer planets (Jupiter, Saturn, Uranus, Neptune) are gas giants composed mainly of hydrogen and helium.
• Inner planets are smaller than outer planets and have less mass.
• Inner planets have fewer moons and no rings.
• Outer planets have numerous moons and prominent ring systems.
• Inner planets orbit closer to the Sun and have shorter orbital periods, while outer planets are further away and have longer orbital periods.
• The asteroid belt is located between Mars and Jupiter.

Other Celestial Objects

• Meteoroids are small pieces of rock or debris in space.
• Meteors are meteoroids that burn up in Earth's atmosphere, creating a "shooting star" effect.
• Meteorites are meteoroids that survive atmospheric entry and land on Earth's surface.
• Comets are balls of ice, rock, and dust that orbit the Sun.
• Asteroids are small, irregularly shaped, rocky bodies orbiting the Sun.
• The Oort Cloud is a vast, icy shell surrounding our solar system.
• The Kuiper Belt is a region beyond Neptune containing icy bodies similar to asteroids.

Galaxies

• Galaxies are large groups of stars bound by gravity.
• The observable Universe contains billions of galaxies.
• The Milky Way galaxy is a barred spiral galaxy.
• Galaxies can interact and merge, creating different structures.
• Dwarf planets, like Pluto, Haumea, and Makemake, exist in the Kuiper Belt.
• KBOs are icy objects made primarily of frozen volatiles like methane, ammonia, and water.
• Comets originate from regions like the Kuiper Belt or Oort Cloud.
• A black hole is a region in space with immense gravity, trapping everything, even light.
• Dark matter is a mysterious substance making up a substantial portion of the universe's mass but not interacting with light.

Scientific Measurement

• Astronomical Units (AU) measure vast distances in space, equivalent to the average distance between the Sun and Earth.
• Light years (ly) calculate distances based on the speed of light traveling through space in a year.