ASTR 305 / HIST 305 Final Exam Practice Flashcards

Flashcards covering astronomical knowledge, history of astronomy, planetary motion, cosmology, and astrobiology based on the lecture notes.

Why do stars appear to rise in the east and set in the west?

Because Earth rotates west-to-east on its axis once every ~24 hours.

What is the definition of the Meridian?

An imaginary line running from north to south through the zenith.

What point in the sky is directly overhead?

The zenith.

What is the North Celestial Pole?

The point in the sky directly above Earth’s north pole.

What do the abbreviations a.m. and p.m. stand for?

a.m. = ante meridiem ("before midday"); p.m. = post meridiem ("after midday").

Why is the star Polaris important for navigation?

It lies very close to the North Celestial Pole, making it appear almost fixed and helping to determine the direction north.

What is the relationship between the altitude of the celestial pole and your location?

The altitude of the celestial pole above the horizon equals your latitude.

How do stars appear to move at the Earth's equator?

Stars rise and set vertically.

What is the difference between practical science and pure science?

Practical science focuses on useful applications (agriculture, navigation, calendars), while pure science is knowledge for understanding nature itself.

What was the significance of the development of Zero in ancient astronomy?

It enabled advanced mathematics, place-value systems, and complex astronomy calculations.

What is a sidereal compass in Polynesian astronomy?

A star compass using rising and setting stars for navigation.

What are the Marshall Island stick charts used for?

They represent wave patterns and island locations using sticks and shells.

The Great Pyramid of Giza was built for which Pharaoh?

Pharaoh Khufu (Cheops).

Why were Egyptian tombs usually built on the west bank of the Nile?

The west was associated with the sunset and the afterlife/death.

Which star's heliacal rising predicted the flooding of the Nile in Ancient Egypt?

Sirius.

Which ancient civilization is credited with dividing daylight into 12 hours?

The Egyptians.

What were the five ancient known planets?

Mercury, Venus, Mars, Jupiter, and Saturn.

What is the sexagesimal system used in Mesopotamian astronomy?

A base-60 numbering system that resulted in 360 degrees in a circle and 60 minutes in an hour.

According to Aristotelian physics, what five elements compose the universe?

Earth, Water, Air, Fire, and Ether (heavens).

What was the primary purpose of the Ptolemaic model (using deferents and epicycles)?

To explain retrograde motion within a geocentric universe.

Why do Moon phases occur?

We see different portions of the Moon’s sunlit half as the Moon orbits Earth.

What are the rise and set times for a Full Moon?

It rises at sunset and sets at sunrise.

What are the two conditions required for a total eclipse?

1. Correct Moon phase; 2. Moon must be near orbital nodes.

What is the "handmaiden thesis" in medieval history?

The view that science was a servant ("handmaiden") to theology.

What was a major argument against Nicolaus Copernicus’s heliocentric model at the time of its proposal?

The lack of observed stellar parallax and contradiction of Aristotelian physics.

What was unique about Tycho Brahe’s geo-heliocentric model?

The planets orbited the Sun, but the Sun orbited the Earth.

What are Johannes Kepler’s three laws of planetary motion?

1. Planets orbit in ellipses; 2. Equal areas swept in equal times; 3. $P^2 \propto a^3$.

List four major telescope discoveries made by Galileo Galilei.

Jupiter’s moons, Venus phases, sunspots, and mountains on the Moon.

What are the two primary types of telescopes and their main components?

Refractors use lenses; Reflectors use mirrors.

What is Newton’s law of universal gravitation?

$F = G \frac{m_1 m_2}{r^2}$.

Who discovered Uranus?

William Herschel.

What did Henrietta Swan Leavitt discover that enabled measuring galaxy distances?

The Cepheid period-luminosity relation.

What is the difference between Blueshift and Redshift in Doppler shift?

Blueshift indicates an object moving toward us; Redshift indicates an object moving away.

What is the Hubble Law formula?

$v = H_0 d$.

How is the age of the universe estimated using the Hubble constant?

$\text{Age of Universe} \approx \frac{1}{H_0}$ (currently estimated at ~13.8 billion years).

What equation represents mass-energy equivalence, and what is its significance in astronomy?

$E = mc^2$; it explains how mass can convert to energy, such as via fusion in the Sun.

When were the first gravitational waves detected by LIGO?

2015.

What did Carl Sagan mean by saying humans are "children of stars"?

The heavy elements in our bodies were formed inside stars.

What was the result of the Urey-Miller experiment?

It showed that organic molecules could form under the conditions of early Earth.

Which element is the backbone of DNA?

Carbon.

What is the Fermi paradox?

The contradiction that if intelligent life is common, there is no evidence or contact from it yet.

What was the first pulsar discovered, and why was it nicknamed LGM-1?

LGM-1 stands for "Little Green Men 1" because the pulses initially seemed artificial.

What are three potentially habitable environments in our Solar System outside of Earth?

Europa, Enceladus, and Titan.

What was the first exoplanet discovered orbiting a sun-like star, and why was it unusual?

51 Pegasi b; it was unusual because it was a "hot Jupiter."

What is the current primary lunar exploration program of NASA?

The Artemis Program.

What is the Gaia hypothesis?

The idea that Earth systems function together somewhat like a living organism.