Online Midterm
Which one of the following ranks the major structures of the Universe from largest to smallest as far as we are concerned? Earth, Local Group, Universe, Virgo Supercluster, Milky Way, Solar System
Local Group, Milky Way, Universe, Earth, Solar System, Virgo Supercluster
Solar System, Earth, Local Group, Milky Way, Virgo Supercluster, Universe
Universe, Virgo Supercluster, Local Group, Milky Way, Solar System, Earth
Just above, Figure 1, is an image of Supernova 1987A that exploded in the Large Magellanic Cloud, an irregular galaxy that is part of the Local Group. The Large Magellanic Cloud is about 170,000 light years away, meaning that the star exploded
2016 – 1987 = 29 years ago
at a distance of 170,000 kilometers.
170,000 years after the Big Bang.
170,000 years ago.
Pluto was reclassified as a dwarf planet because it does not meet one of the three criteria a Solar System object must meet to be called a planet. The three criteria are listed below. Which criteria (or criterion) does it fail?
It is in orbit around the Sun.
It has “cleared the neighborhood” around its orbit.
It has sufficient mass to assume hydrostatic equilibrium (a nearly round shape).
Pluto fails all of the criteria.
The following is a list of “theories.” Three are defined by the everyday meaning of the word “theory.” Which one is the scientific theory?
A brainstorming session leads to an idea of what might make the Earth rotate.
Someone uses their intuition to guess whether a pair of dice will roll a seven.
A thoroughly tested and verifiable model that can predict when a tornado will form.
A sports fan makes a prediction of who will win next year’s football superbowl.
In the northern hemisphere, the altitude of Polaris (current star closest to the North Celestial Pole) above the northern horizon is equal to a person’s latitude on Earth. Let’s say you were sailing north from the Galápagos Islands that lie across the Earth’s equator. If you took readings of Polaris each night you would find that
Polaris got lower and lower in the sky.
Polaris got higher and higher in the sky.
Polaris rose in the north and set in the south.
Polaris’s height above the northern horizon did not change.
