PSU Astro 7N Midterm Exam 1 2025

What two properties of a planet affect the gravity we feel on its surface? - Correct Ans-Mass and radius Two planets have the same radius. If Planet A is 5 times more mass than Planet B, how does gravity differ on the surfaces of the two planets? - Correct Ans-Gravity is 5 times stronger on planet A Say that there were a planet X in our Solar System with a mass 1/4 the mass of Earth and a radius 1/2 the radius of Earth. How will the gravity on its surface compare to the surface gravity of Earth? - Correct Ans-Surface gravity on planet X is the same as on earth A planet in a nearly circular orbit with its rotation axis tilted by 5 degrees relative to its orbital plane around its star would ... - Correct Ans-Have seasons that are not very different from each other as compared to Earth The rotation axis of the Earth is ... - Correct Ans-Tilted at about 23 degrees relative to the axis of the Earth's orbit around the Sun In the diagram above, what season and planet is being represented by the red X on the planet on the left in orbit around the Sun? - Correct Ans- When is the waning gibbous moon highest in the sky? - Correct Ans-About 3 am What phase is the Moon in, when observed by the person standing on the Earth in the diagram above? - Correct Ans-New At what time will the Moon set on the day of a Solar eclipse? - Correct Ans-Sunset Stars that are in the same constellation ... - Correct Ans-are likely to be at very different distances from us. The "North Star" is a star in the constellation of Ursa Minor, which lies just above the North pole of Earth. Which of the following is true? - Correct Ans-Ursa Minor is a Zodiac constellation in the summer but not in the winter A particular Zodiac constellation is high in the sky at midnight in April. Where will it be in October? - Correct Ans-Near the Sun in the daytime sky What do you expect the spectrum of an object that is 1,000,000 Kelvin to be like? - Correct Ans-It should peak at X-ray wavelengths As compared to a cool star, a hotter star emits ... - Correct Ans-Shorter wavelength, higher frequency, bluer color Radio waves can travel large distances without interference because ... - Correct Ans-They have longer wavelengths than visible light Compared to ultraviolet radiation, X-rays have a wavelength that is ... - Correct Ans-Shorter Star A is 4000 K, and Star B is 8000 K. Which of the following is true? - Correct Ans-The color of Star A is redder than Star B In the diagram above, what is happening in the box in the center? - Correct Ans- A star is a hot, dense gas surrounded by a cooler, low density atmosphere. What type of spectrum will a star create? - Correct Ans-Absorption Spectrum What makes a transition from a lower energy state to a higher energy state when a photon is absorbed into an atom? - Correct Ans-Electron An emission line is produced when: - Correct Ans-An electron passes from a higher to a lower energy level Bright lines in an emission spectrum represent: - Correct Ans-particular energies of light that are emitted from a distant object The faintness of an object that a telescope can observe is mostly determined by the ... - Correct Ans-Diameter of the opening of a telescope In what ways does a 5 meter telescope outperform a 1 meter telescope?I - Correct Ans-its images are 25 times brighter than a 1 meter A mountain top is a good location for optical telescopes because the site ... - Correct Ans-Is above much of the atmosphere Which statement about the rotation of the Inner planets is true? - Correct Ans-Venus rotates in the opposite direction from the three other inner planets Which of the following is TRUE? - Correct Ans-Mercury rotates exactly one and a half times for every one revolution around the Sun. Why do the orbits of the planets all lie in nearly the same plane? - Correct Ans-The early solar nebula flattened into a disk. Of these choices, which planet has the most moons? - Correct Ans-Saturn has more than Earth, Mercury, Mars, and Venus Venus is visible to us ... - Correct Ans-only near sunrise or sunset A planet is in orbit around the Sun. The semimajor axis of the orbit is 5 Astronomical Units (AU). Use P^2 = a^3 to calculate the period of the orbit, in years. - Correct Ans-11.2 years In the above diagram, how should the parameters of the white curve be changed in order that it matches the observed distance versus time graph of Callisto? - Correct Ans-increase P and shift the curve How do most craters on moons form? - Correct Ans-impact of asteroids Which planet has a temperature of 800 degrees Fahrenheit on the side facing the Sun and -290 degrees Fahrenheit on the side opposite the Sun? - Correct Ans-Mercury How many Earth years does it take Uranus to orbit the Sun? - Correct Ans-84 Meteors are ... - Correct Ans-asteroids or comet debris that passes into Earth's atmosphere and burns up Which feature of Neptune is most responsible for its blue color? - Correct Ans-methane in its atmosphere Which of the following statements is TRUE? - Correct Ans-The planet Saturn has more than 30 moons. The surface of Venus is hotter than the surface of Mercury because ... - Correct Ans-Venus is more massive and is able to retain a thick atmosphere. Which of the following is moving fastest in the orbit? - Correct Ans-Venus at its perihelion (closest point to Sun) Which of the following is FALSE? - Correct Ans-Saturn has a density of 4.8 grams per cubic centimeter, similar to metals like aluminum and iron Which of the following objects have a dark/black sky, even in the daytime? - Correct Ans-both the Moon and Mercury Which of the following is the largest distance? - Correct Ans-the distance from Jupiter to Saturn Where on the Venn diagram, above, does the clue "Tail always points away from the Sun" belong? - Correct Ans-C (See practice questions) Which of the following is NOT required in order to classify a Solar System object as a planet (instead of a dwarf planet)? - Correct Ans-It must be larger than all of the moons in the Solar System Which of the following planets looks the most like the Earth's Moon? - Correct Ans-Mercury Which is NOT a characteristic of a comet? - Correct Ans-most orbit the Sun in between the orbits of Mars and Jupiter Which of the following is the cause of an aurora? - Correct Ans-Solar wind particles that hit the atmosphere of a planet In the diagram above, which planets have temperatures lower than -200 degrees Fahrenheit? - Correct Ans-all the Jovian planets (See practice questions) Which planet is this in the picture? (to the right) - Correct Ans-Venus (See practice questions) The moon has about 1/100th the mass of Earth and 1/4 the radius. What is the surface gravity of the Moon compared to the Earth? - Correct Ans-16/100 What did Newtons law of Universal Gravitation tell us about how gravity works? - Correct Ans-The force of gravity from the Sun will be stronger on a larger mass object According to Newton's second law of motion, if the net force acting on the object increases while the mass of the object remains constant, what happens to the acceleration? - Correct Ans-acceleration increases Longest day of the year in the northern hemisphere - Correct Ans-June 21 Shortest day of the year in the Northern Hemisphere - Correct Ans-December 21 What time of year is it dark all day (and night) at the South pole? - Correct Ans-June Earth's Moon was Full on May 1, 2007. When was it next in the First Quarter phase after this Full Moon? - Correct Ans-May 22 A moon orbits a planet in exactly the same plane as the planet orbits its star. How often does this planet experience a solar eclipse? - Correct Ans-Once every orbit of its moon (its month) When is the best time for you to be able to see the constellation that is your sign of the Zodiac? - Correct Ans-At midnight six months after your birthday Constellations close to the North pole of Earth - Correct Ans-Move in a circl