Astronomy - Quiz 2

Ancient Greek Astronomers

used models and observations to be the first to use a careful and systematic manner to explain the workings of the heavens; their idea of using logic and mathematics as tools for investigating nature is still used in modern society.

Retrograde Motion

When a planet moves from east to west relative to the stars. The explanation of retrograde motion was one of the main reasons why the Earth being located at the center of our solar system was rejected.

The Geocentric Model

developed to explain the general east to west motion of objects; the model featured the Earth being at the center of the universe.

Epicycles

When the geocentric model was improved by Ptolemy of Alexandria, he assumed each planet moved on a small circle, where in turn its center moves on a much larger circle centered on the Earth. These small circles were called ________.

Copernicus

An astronomer who lived till 1473-1543, he could not reconcile centuries of data with Ptolemy’s geocentric model, he reconsidered Aristarchus heliocentric model with the sun at the center of the solar system. His success included publishing the first heliocentric model, where it explained retrograde motion as a natural consequence of the two planets passing each other. In addition to that, he could also derive the relative distances of the planets from the Sun and explain why Venus and Mercury were always close to the Sun.

Galileo Galilei

An astronomer who lived until 1564-1642.  He worked in the same period as Johannes Jepler, being the first person to use the telescope to study the heavens and offer interpretations. He also observed that the Sun has spots, and it is not perfect, it changes its appearance and rotates. In addition to that, he found that Jupiter has four objects orbiting it, which are moons. Lastly, He identified that the Milky Way was populated by an uncountable number of stars, making the Earth-centered universe too simple.

Tycho Brahe

An astronomer who lived until 1546-1601, he designed and built instruments of far greater accuracy than any yet devised; made meticulous measurements of the planets of the solar system.

Johannes Kepler

An astronomer who lived until 1571-1630, Upon Tycho’s death, his data was passed to Kepler, his young assistant. He used the very precise Mars data, showing the orbit of Mars to be an ellipse.

Isaac Newton

An astronomer who lived until 1642-1727. He was born the same year Galileo had died. Made many major advances in math, physics and astronomy. Isaac Newton realized that the motion of the falling apple and the motion of the Moon were both actually the same motion, caused by the same force (gravitational force). He also realized that the force that brought the apple to the ground was the same force that caused the Moon to orbit the earth.

Refractor

A _____ telescope is composed of at least two lenses; it uses a lens at the front of the closed tube to gather and focus light, known as the objective lens.

Sacharias Janssen

A spectacle maker in Middelburg who lived until 1585-1632. One of the possible inventors of the telescope, his son said that his father built his first telescope before 1609, following an Italian device dated 1590.

First Observation of the Moon

Discovered craters and mountains, which concluded that celestial bodies were not smooth and perfect.

First Observation of the Sun

Harriot, Galileo, Scheiner and Johannes Faricius found dark spots on it.

The First Observation Of Jupiter

Galileo observed with a refractor enlarging 20 times where He saw three giant stars that appeared close to the planet. They were indeed not stars but satellites orbiting it, and they also do not revolve around our planet.

Reflecting Telescopes

Glass is not the only thing with peculiar properties. Instead of combining lenses, mirrors can be used. Isaac Newton built the first one in 1668.

Aperture

A telescope's ability to collect light is directly related to the diameter of the lens or mirror that is used to gather light. The larger the aperture the more light the telescope collects

Magnification

The telescope's eyepieces ability to enlarge an image. It depends on the combination of lenses used. Any magnification can be achieved by almost any telescope by using different eyepieces. Aperture is a more important feature than magnification.v ff

Filters

A piece of glass or plastic that you can place in the barrel of an eyepiece to restrict the wavelengths of light that come through in the image. Used to enhance the viewing of faint sky objects in light-polluted skies, enhance the contrast of fine features and details on the moon and planets and to safely view the sun.

Characteristics of The Moon

A satellite that only reflects the light from the sun; does not provide any light on its own. It has a nickel-core. The moon wobbles (libration) which makes it possible for humans to see roughly 51% of the Moon’s surface. It has many different features including mare (seas or lava formed plains, terra (highlands), craters (created from asteroid and meteorite impacts and mons (mountains.)

Nebular/Condensation Theory

The Earth and Moon were produced

or created at the same time in the same or close

nebulas during the creation of the Solar System.

Capture Theory

Where Earth’s gravity pulled the Moon in while it was passing near Earth.

Collision Theory

an asteroid or something large in size hit the primordial Earth forcing back of the remnants (orbiting clouds of debris) soon clustered together over time to become our Moon.

Phases of the Moon.

During a period of about 30 days, the Moon goes through a complete set of phases: waxing crescent, first quarter, waxing gibbous, full, waning gibbous, third quarter, waning crescent

Eclipse

when the Sun, Earth, and Moon are directly in line with each other

Solar Eclipse

occurs when the Moonpasses between the Sun and Earth, with the Moon casting its shadow on the Earth causing a midday sky to become dark as night for a few minutes

Lunar Eclipse

occurs when the Earth passes between the Sun and Moon, with the Earth casting its shadow on the Moon giving it a dull red color

Red Moon

Earth’s atmosphere bends some sunlight into the shadow; light reaching the moon is red because interactions with particles in the air bend red light more than other colors of the rainbow.

Blue Moon

During the course of a year, it is possible to have 13 Full Moons. In the case of a 13-Full-Moon year, one month has two full moons. When a month has TWO FULL MOONS, the second Full Moon is called the ____________.