21st Century Astronomy
6th Edition
ISBN: 9780393428063
Author: Kay
Publisher: NORTON
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Chapter 1, Problem 37QP
(a)
To determine
The time that takes for light from Neptune to reach Earth.
(b)
To determine
The problem when
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Suppose we find an Earth-like planet around one of our nearest stellar neighbors, Alpha Centauri (located only 4.4 light-years away). If we launched a "generation ship" at a constant speed of 1500.00 km/s from Earth with a group of people whose descendants will explore and colonize this planet, how many years before the generation ship reached Alpha Centauri? (Note there are 9.46 ××1012 km in a light-year and 31.6 million seconds in a year.
While looking through the Mt. Palomar telescope, you discover a large planetary object orbited by a single moon. The moon orbits the planet every 7.35 hours with the centers of the two objects separated by a distance roughly 2.25 times the radius of the planet. Fellow scientists speculate that the planet is made of mostly iron. In fact, the media has dubbed it the ''Iron Planet'' and NASA has even named it Planet Hephaestus after the Greek god of iron. But you have your doubts. Assuming the planet is spherical and the orbit circular, calculate the density of Planet Hephaestus.
Suppose you send a probe to land on Mercury, and the probe transmits radio signals to earth at a wavelength of 52.0000 cm. You listen for the probe when Mercury is moving away from Earth at its full orbital velocity of 48 km/s around the Sun. What wavelength (in cm) would you have to tune your radio telescope to detect that signal?
Use the doppler shift formula Note: the speed of light is 3.0 ✕ 105 km/s. Give your answer to at least four decimal places.)
Chapter 1 Solutions
21st Century Astronomy
Ch. 1.1 - Prob. 1.1CYUCh. 1.2 - Prob. 1.2CYUCh. 1.3 - Prob. 1.3CYUCh. 1 - Prob. 1QPCh. 1 - Prob. 2QPCh. 1 - Prob. 3QPCh. 1 - Prob. 4QPCh. 1 - Prob. 5QPCh. 1 - Prob. 6QPCh. 1 - Prob. 7QP
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- Please answer the following A) Suppose an object takes 1000 years to orbit the Sun. How many times farther from the Sun is it, when compared with Earth? B) Communications with the spacecraft Alpha using radio waves require 2000 years for the round trip (there and back). This implies that Alpha is how many light years away from Earth?arrow_forwardYou are working for a new assistant professor in astronomy who is interested in exoplanets. One day, a scientific rumor begins circulating that there is a Jupiter-sized planet around Alpha Centauri, 4.28 light-years away. Your professor has access to viewing privileges for the Hubble Space Telescope (aperture diameter 2.4 m, 100 nm to 2 400 nm), the Hale Telescope on Palomar Mountain in California (aperture diameter 5.08 m, visible light), the Keck Telescope on Mauna Lea, Hawaii (aperture diameter 10.0 m, visible light), and the Arecibo Radio Telescope in Puerto Rico (aperture diameter 305 m, 75-cm radio waves). He asks you to advisehim as soon as possible as to which telescope he should request time on in order to resolve an image of the planet.arrow_forwardKepler’s First Law: Elliptical Planetary Orbits: The solar system major planet in the most elliptical solar orbit is little Mercury, which is the closest planet to the Sun. At Perihelion, Mercury’s distance from the Sun (Rp) is 0.31 AU. At Aphelion, Mercury’s distance from the Sun (Ra) is 0.47 AU. The intensity of Sunlight (I) that a planet receives from the Sun is inversely proportional to the square of that planet’s distance from the Sun (R). in other words, I = Constant / R2. Calculate how much more intense the Sunlight received by Mercury is at perihelion (p) than at aphelion (a): Rp2 = Ra2 = Ip / Ia = Ra2 / Rp2 =arrow_forward
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