Earth is one of ___ planets that orbit the sun in our solar system
eight
the sun has no solid surface, but rather it is a huge ball of very hot gas containing ___ % of H (hydrogen), and ___% of He (helium)
75% of H
25% of He
the planets in our solar system orbit the Sun in the same direction
true/false?
true
What are the terrestrial planets in our solar system?
Mercury, Venus, Earth, and Mars
Describe the terrestrial planets
small, rocky, inner plannets
What are the Jovian planets in our solar system?
Jupiter, saturn, uranus, neptune
Describe the Jovian planets
huge, outer planets, also referred to as "gas planets"
What are the small bodies in the solar system called?
when its 1000km or less in diameter, it is a asteroid and/or a comet
Asteroids are rocky or ____ objects
metallic
Most asteroids lie in the "asteroids belt" _____ the orbits of Mars and Jupiter
between
Comets are ___ bodies
icy
Comets are found in two "reservoirs" called
!.
2.
1.The Kuiper Belt (Directly Observed)
2.The Oort Cloud (Theoretical)
Define the Nebular Hypothesis of the origin of the planets
the solar system originated from a rotating, flattened disk of gas and dust known as the solar nebula
how did planets and moons form?
from dust clumping together to form plantesimals which further clumped into planets
The Earth's _____ is its only natural satellite
moon
the eaths moon is about ____ the diameter of the Earth
1/4th
Mercury is the _______ inner planet, and resembles Earth's moon in both size and apperance
smallest
Mercury has
1. ____ atmosphere
2.Large ___ core
1. no atmosphere
2.Large iron core
Venus has the ______ planetary surface in the solar system
hottest
Venus has a thick ___ atmosphere which creates a _______ effect
CO2, greenhouse
Mars has a diameter about ____ of Earths and has the most _____-like structures
half; Earth
Mars is where our teacher aspires to go... because of all the aspects that make it Earth-like, for example, its thin ___ atmosphere, about __% as thick as Earths