Unit 1 Assignment Questions With regards to astronomy, the ancient Mayan culture is best known for... Developing a sophisticated calendar that incorporated the changing positions of Venus among the stars of the right. Astronomers measure the objects east/west position in the sky using a measure called… Right Ascension What is the maximum angle that the moon can appear above or below the ecliptic plane? 5.2 Degrees A penumbral lunar eclipse occurs when At least some part of the moon passes through the earth’s outer shadow The apparent motion of celestial objects across our sky that is due to Earth’s rotation is called “Diurnal motion”. True When measuring Right Ascension across the sky, "1 hour" of right ascension is equivalent to an angle of _______ degrees of arc. 15 The earliest type of device humans used for keeping track of time was probably some sort of sundial. It reckoned the time by using the position of the Sun in the sky. Now, we call the type of time that sundials measure as... Apparent solar time A photon travelling away from the sun at the speed of light would cover a distance of ___ in a year 9.46 trillion kilometers On average, approximately how fast does the shadow of the moon move as it crosses the surface of the earth? 1500 km/h Lunar eclipses can only happen during a... Full moon If the Moon's disk appears half lit in the sky and is almost overhead just as the Sun is rising, its phase is called __________________. Third Quarter As the Earth rotates, celestial objects visible in the night sky are seen to rise over the eastern horizon, move across the sky and eventually set below the western horizon. Their path across the sky is at some angle to the southern horizon due the observer's latitude location on Earth. This means that at some point in their path across the sky, they reach a position where they appear due south from the observer. At this point, the objects are at their highest point above the horizon. When it reaches this location, astronomers say the object has reached its Transit Points The Moon's orbital path around the Earth is not perfectly circular. For this reason, the moon's apparent size in the sky changes slightly during each cycle around our planet. When the moon is at its farthest from Earth Apogee Because of "precession", the Earth's polar axis will align with a different "North Star"14,000 years in the future. What is the name of this star? Vega There are two types of solar eclipse that are visible from Earth's surface. During an annular solar eclipse.... The moon in its orbit, is farther from earth than its average distance As the moon moves in its orbit, it appears to an observer to shift eastward relative to the stars around it each night. About how far eastward does the moon appear to move relative to the stars around it each hour? The moon appears to move eastward 0.5 degrees every hour In the northern hemisphere of Earth, the period from late June to late September is the warmest season of the year because... 1) During this time period, the Earth is closer to the Sun in its orbit than at any other time of the year. 2) During this time period, the Sun is above the horizon in the northern hemisphere longer than at any other time of the year. 3) During this time period, sunlight in this hemisphere reaches the ground and warms it more efficiently than at any orther time of the year. 4) During this time period, the Earth's north pole is tilted more towards the Sun that at any other time of the year. only answers 3) and 4) are correct Because of Earth's motion in its orbit while the moon circles around it, a synodic month takes ___________________________________________ than a sidereal month. 2.2 Days more If you are on the Earth's surface and standing inside the Earth's umbra, then... You must be experiencing a Total solar eclipse When viewed from the Earth's surface, the Sun's apparent path moving through the constellations of the celestial sphere each year (due to Earth's motion around the Sun) is known as... The ecliptic On the day of a "solstice", there will be equal hours of daylight and darkness at every location around the world. False According to our textbook, if we mapped the time that our universe has existed on a calendar, with the moment of the start of the universe (the "Big Bang") occurring at the first instant of January 1st and the present moment on the last tick of the day on December 31st, on which day of that cosmic calendar year did our solar system form? Around September 10th Although scientific theories can never be proven to be correct with 100% certainty, they can be proven wrong with 100% certainty. True When we look up at the night sky, there is a group of constellations through which the other planets and the Sun appear to travel over the course of a year. This sets this group of constellations apart from the others that we recognize in the sky. This collection of constellations is referred to as... the zodiacal constellations Unit 2 Assignment questions In Bohr's model of the atom, electrons Only makes transitions between orbits of specific energies Max Planck was the first to show theoretically that light can behave as both a wave and as a particle. False You count 6 wave crests (5 complete waves) pass your anchor rope in exactly 60 seconds. What is the frequency of the waves? 0.083 Hz Which of the following sequences, place the types of electromagnetic waves listed in the correct order from shortest wavelength --> to --> longest wavelength? Ultraviolet, Visible Light, Infrared, Microwave, Radio Wave In order to explain how light waves were able to travel through space, many astronomers of the 19th century believed that space itself must be made up of tiny undetectable particles which they called "bosons". False Known as the Zeeman effect, it was determined that phenomenon was caused by … The increase and decrease in strength of the magnetic fields around sunspots "The intensity of light arriving from a source in space (eg. a star) weakens at an accelerated rate as the distance from the source increases". This statement describes.... The inverse square law Which of the following properties cannot be determined through analyzing spectral lines? an object's rotation rate (or even if there is one) the chemical composition of an object the average density of the object the average surface temperature of the object the line-of-sight velocity of the object relative to Earth Stefan-Boltzmann's Law notes that the total energy radiated by a 'blackbody' is proportional to the ____________________ of its overall temperature. Fourth power In the Kelvin temperature scale, the temperature of "absolute zero" is equivalent to... Zero Kelvins (See part 3 of lecture slides or resources folder) about doppler effect moving towards/away from us and calculating speed In which of the following portions of the EM spectrum are electromagnetic waves able to penetrate the atmosphere and reach Earth's surface? All waves in the visible portion of the spectrum, some in the infrared region and some radio wavelengths can penetrate and reach the surface. An absorption spectral line results from an electron falling from a higher to lower energy orbital around its atomic nucleus. False Which of the following statements best describes the types of particles that are responsible and the conditions under which they create the EM waves? Only particles with either a negative charge or a positive charge that are accelerating or decelerating within an object create EM waves. In trying to visualize the size of specific forms of electromagnetic waves, it can be said that ultraviolet waves have wavelengths comparable in size to a(n)... microscopic virus GO OVER KIRCHOFF’s LAWS Joseph Fraunhofer was the German astronomer who in 1815... first identified hundreds of absorption lines in the Sun's visible light spectrum. Who was the first scientist to experimentally prove that the Electromagnetic Theory (that light is actually made up of electromagnetic waves) was correct? Heinrich Hertz What is true of a blackbody? Its temperature controls the wavelength at which its energy output is the strongest. Which of the following colours has a wavelength longer than the others? RED In general, the spectral lines of molecules are More complex than those of atoms A gaseous nebula, glowing because its atoms are being excited by energy radiated from hot young stars nearby, emits its own spectrum of electromagnetic waves that is observed by astronomers as... only emission lines on a black background. Unit 3 Assignment Questions The point in an object's orbit where it is farthest from the planet that it is orbiting (and traveling the slowest in its orbit) is known as... The Apogee Point History shows that there was an astronomer in the ancient world who was the first to deduce the Earth's rotation, first to propose a sun-centred model of the universe with all the planets in the correct orbital order, and who was also the first to argue that the Sun was larger than the moon - up to twenty times larger. However, due to the politics of his time, his astronomical work was basically ignored for over 1000 years. Who was he? Aristarchus An asteroid with an orbital period of 8.3 years. Using Kepler’s third law what is the average distance from the Sun? About 4 astronomical units What is meant by Kepler's second law, which states that as a planet moves around its orbit it sweeps out equal areas in equal times? a planet travels faster when it is nearer to the Sun and slower when it is farther from the Sun. Which of the following best defines " 1 astronomical unit" ( 1 AU)? The average distance from the earth to the sun One famous astronomer made such thorough and accurate drawings and written observations of the Moon, that it convinced many of those who saw/read them to believe that the Moon might be not so different from Earth. This conclusion led the astronomer to further argue that Earth itself could also be a celestial body, like other planets. Who was this astronomer? Galileo What was the most significant reason for Galileo's hard work to improve the design of his first refracting telescope? He thought he could make money selling it to Venetian merchants The type of orbits of most comets visiting the inner solar is _____________________. Parabolic planets were thought to orbit (grey circle) around a central point (violet dot) that was embedded in a crystal sphere (red circle) that itself rotated around the Earth. This supposedly created the looping motion observers saw planet making as they moved across the sky. What was the name given to the grey circle to which a circling planet is attached? (Name the object indicated by the grey arrow) Epicycle A golfer hits a golf ball such that it leaves the tee on upward-angled trajectory towards the flag on the green. While the Earth exerts a gravitational pull on the ball that alters the ball’s path and pulls it back toward the ground, the ball is itself exerting a gravitational pull of equal strength back on the Earth. True What does the Greek word "planet" mean? Wanderer The geocentric system for predicting planetary positions that remained in use for some 1,500 years was created by_________? Ptolemy The motion of a body that is under the gravitational influence of two or more other bodies can only be calculated accurately through the use of power computer processors. (hint: see online textbook section 3.6) True According to Newton's Universal Law of Gravitation, which of the following factors effect the strength of the gravitational pull between two objects? 1) the mass of object A 2) the mass of object B 3) the distance between the centres of object A and B 4) the strength of the gravitational field of each particle in each object "For every action there is an equal and opposite reaction" (or: the mutual actions of two bodies upon each other are always equal and act in opposite directions). This statement is a description of... (Hint: see online textbook, section 3.2) Newton's Third Law of Motion _______________________'s very accurate observations were valuable in the development and testing of ___________________'s theories. Tycho Brahe; Kepler The heliocentric model of the solar system that Copernicus proposed was different from earlier geocentric models in several important ways. One key prediction that it made was that as Venus moves through its orbit, observers should be able to see it illuminated in different phases from Earth. Which of the phases does his model predict we would see? 1) Crescent 2) New 3) Gibbous 4) Full Imagine a boy sitting on a spinning stool. He sits with his arms out. His friend then begins to spin him on the stool. What happens to his spin speed when he pulls his arms inward? His speed increases because the distance to the spin axis has decreased. Who compiled the only surviving "textbook" of constellations, star charts, and data on planetary positions, preserved from the ancient world? Ptolemy According to Copernicus, the retrograde motion for Mars must occur at opposition, when the Earth overtakes Mars and passes between Mars and the Sun. With the invention of his astronomical telescope, Galileo was able to make several important observations that convinced him that the ideas of the geocentric model that had been taught for over 1500 years in Europe were wrong. Which of the following was NOT one of those observations? He saw white polar caps on Mars grow and shrink in a repetitive pattern that matched with the orbital period of the planet. The speed that a spacecraft needs to escape the Earth's gravitational pull and move out of Earth orbit is known as the 'escape velocity' for the Earth. How fast does a spacecraft need to be traveling to reach escape velocity? 11 km/s To describe the eccentricity of a planet's orbital path around the Sun, an observer would need to know two other properties of the planet's elliptical orbit. First, they would need to know the distance between the two foci in its elliptical path. Second, they would also need to know the ___________________. Length of the orbit’s major axis Astronomers refer to a planet’s apparent eastward motion through the constellations over many months as __________ motion across the sky. Prograde Pythagoras was the first to measure the approximate diameter of the Earth by first using geometry to measure the angle of the Sun's light in Alexandria, Egypt on the day of the Summer Solstice. False
