Qtr. 1 Lesson 1: Our World At A Glance Flashcards
(33 cards)
This model describes our universe forming from a sudden and rapid expansion from which all known matter is said to have emerged.
Big Bang model
As the universe began to stabilize, temperatures gradually decreased and particles began to coalesce, forming _____. These _____, in turn, began to form the elements that would become the foundation of matter in our universe.
atoms
The first heavenly bodies formed small knots in great gas clouds that became _____.
galaxies
An important discovery which greatly supports the Big Bang model is the discovery of _____.
cosmic background radiation
It is the most widely accepted model of the formation and evolution of our solar system.
Nebular Hypothesis
The ___ is the dominant astronomical object in our system, composing 99.9% of the entire mass of the solar system.
Sun
The ____ is situated in the most optimal distance from the sun—not too close as to experience extreme temperatures and radiation, and not too far away as to become too cold.
Earth
Other objects such as the dwarf planets ___, ___, and ___, asteroids, meteors, and comets are also within our solar system.
Pluto, Eris, and Ceres
At present, several _____ orbit our planet, with a number of them orbiting the vast expanse of our solar system as probes that study the other planets and other astronomical objects.
man-made satellites
_____ is the study of the origins and eventual fate of the universe. Cosmologists look at how the universe evolves and the natural laws that keep it in order.
Cosmology
_____ is the study of celestial objects and other interstellar phenomena.
Astronomy
_____ is a branch of astronomy that studies physical properties of celestial objects, their behaviors, and interactions.
Astrophysics
_____ is a massive system composed of stars, interstellar objects, and dust clouds. This system contains several star systems and clusters.
Galaxy
_____ refers to groups of galaxies bound together in a loose or tight formation often displaying the same pattern of movement across the universe.
Cluster
_____ is a large group of clusters. These are among the largest structures in the universe.
Supercluster
_____ is an interstellar cloud of dust and gas in the universe. Stars and planets were formed in nebulas.
Nebula
_____ is a Greek word that means “wanderer” or “wandering star”
Planet
The conditions of Earth upon its formation about 4.5 years ago is described as “_____”.
hellish
Scientists have described the Eartg as being in the “_____” in the solar system, where the conditions were sufficient to encourage the emergence of life on the planet.
“habitable zone”
About 2.5 million years ago, the surface of the Earth became more solid and stable, and within a few million years several developments occurred which rendered the Earth more habitable.
True
The early oceans played an important part in changing the early climate.
True
The first signs of life emerged from these oceans, one-celled organisms called _____.
prokaryotes
_____ is a single cell organism which include bacteria. These organisms are able to survive environments with harsh conditions, such as high temperature and salinity.
Prokaryotes
A number of early organisms called cyanobacteria produced food through _____.
photosynthesis
