Concept explainers
(a)
The speed of earth in its orbit.
Answer to Problem 26Q
The speed of earth in its axis is
Explanation of Solution
Given:
The radius of Earth orbit is,
Formula Used:
The expression of speed of earth in its axis is given by,
Calculation:
The speed of earth in its axis is calculated as,
Conclusion:
The speed of earth in its axis is
(b)
The wavelength of transmission which Earth receives.
Answer to Problem 26Q
The wavelength of transmission which Earth receives is
Explanation of Solution
Given:
The frequency is
Formula Used:
The expression of wavelength is given by,
Calculation:
The wavelength is calculated as,
Conclusion:
The wavelength of transmission which Earth receives is
(c)
The shift in wavelength using Doppler Effect.
Answer to Problem 26Q
The shift in wavelength is
Explanation of Solution
Formula Used:
The expression of shift in wavelength is given by,
The expression of percent shift in wavelength is given by,
Calculation:
The shift in wavelength is calculated as,
The percent shift in wavelength is calculated as,
Conclusion:
The shift in wavelength is
(d)
The importance that SETI radio receivers be able to measure frequency and wavelength to very high precision.
Explanation of Solution
Introduction:
SETI pioneer Bernard Oliver was the first one who draws attention to a range of relatively noise-free frequency in the neighbor-hood of the microwave emission lines of hydrogen and hydroxide.
It is essential to track all the frequency and wavelength sent by civilization in another planetary system. So, there is a requirement of high precision technology to detect that frequency to communicate with them.
Conclusion:
Therefore, there is a requirement of a high precision radio receiver which able to measure frequency and wavelength.
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Chapter 27 Solutions
UNIVERSE (LOOSELEAF):STARS+GALAXIES
- In a globular cluster, astronomers (someday) discover a star with the same mass as our Sun, but consisting entirely of hydrogen and helium. Is this star a good place to point our SETI antennas and search for radio signals from an advanced civilization? Group of answer choices No, because such a star (and any planets around it) would not have the heavier elements (carbon, nitrogen, oxygen, etc.) that we believe are necessary to start life as we know it. Yes, because globular clusters are among the closest star clusters to us, so that they would be easy to search for radio signals. Yes, because we have already found radio signals from another civilization living near a star in a globular cluster. No, because such a star would most likely not have a stable (main-sequence) stage that is long enough for a technological civilization to develop. Yes, because such a star is probably old and a technological civilization will have had a long time to evolve and develop there.arrow_forwardWhen Mars is 90 million km (9 x 10^10 m) from Earth, a) How long would it take for a radio wave from a video camera mounted on the back of a Mars Rover to tell ground control on earth that the Rover is about to go over a cliff? b) How long would it take for a radio signal from Earth to reach the Rover saying "STOP". c) Why do our Mars Rovers have to be "intelligent" enough to figure out how to deal with obstacles themselves?arrow_forwardYou decide to go on an interstellar mission to explore some of the newly discovered extrasolar planets orbiting the star ROTOR. Your spacecraft arrives in the new system, in which there are five planets. ROTOR is identical to the Sun (in terms of its size, mass, age and composition). From your observations of these planets, you collect the following data: Density Average Distance from star (AU] Planet Mass Radius Albedo Temp. [C] Surf. Press. MOI Rotation [Earth = 1] (Earth = 1] [g/cm³] [Atm.] Period (Hours] Factor SIEVER EUGENIA 4.0 0.001 2.0 0.1 5.0 1.0 0.3 20 0.8 N/A 3.0 0.2 N/A 0.3 0.4 0.35 20 10 500 1000 5.0 4.0 0.5 0.8 0.4 0.7 -50 MARLENE CRILE 1.0 1.0 3.0 8.0 1,5 0.0 0.50 0.50 0.25 150 0.4 JANUS 100 12 0.1 10 -80 0.2 200 Figure 1: А Rotor 850 890 900 Wavelength (nm) A Sun В C 860 900 910 Wavelength (nm) 2414 a asarrow_forward
- We think the terrestrial planets formed around solid “seeds” that later grew over time through the accretion of rocks and metals. a) Suppose the Earth grew to its present size in 1 million years through the accretion of particles averaging 100 grams each. On average, how many particles did the Earth capture per second, given that the mass of the Earth is = 5.972 × 10 ^24 kg ? b) If you stood on Earth during its formation and watched a region covering 100 m^2, how many impacts would you expect to see in one hour. Use the impact rate you calculated in part a. You’ll need the following as well: the radius of the Earth is = 6.371 × 10 ^6 m and the surface area of the Earth is 4??^2Eartharrow_forwardSince 1995, hundreds of extrasolar planets have been discovered. There is the exciting possibility that there is life on one or more of these planets. To support life similar to that on the Earth, the planet must have liquid water. For an Earth-like planet orbiting a star like the Sun, this requirement means that the planet must be within a habitable zone of 0.9 AU to 1.4 AU from the star. The semimajor axis of an extrasolar planet is inferred from its period. What range in periods corresponds to the habitable zone for an Earth-like Planet orbiting a Sun-like star?arrow_forwardFor which of the following reasons (select all that apply), is it useful/important to send rovers to other planetary bodies in our solar system? O a. The engineering innovations developed to produce successful/viable rovers and landers on other planets can help lead to developments in the technology used here on Earth that may have taken far more time to develop without the limitations provided by space travel to foreign worlds. O b. The data collected can help improve our understanding of the evolution/development of our solar system. O. Rovers/landers can be outfitted with various tools and equipment that can be used to inform of us of the geological histories of each of the planets they visit. O d. More direct probes of the planetary surface are possible to detect signs of the building blocks of life. O e. Rock samples can be used to calibrate our estimations of the age of the solar system.arrow_forward
- Calculate how long radio communications from the spacecraft will take when it encounters Mars. The furthest distance from Earth to Mars is 2.66 AU. Remember that 1 AU = 1.5 x 1011 m and that light travels at 3 x 108 m/s. So how long will the radio messages take to travel this greatest distance of 2.66 AU? If two way communication between the Earth and the spacecraft involve a 1 s time lapse before an acknowledging signal is sent by the spacecraft, how long a time is there between sending a command to the spacecraft and receiving a reply?arrow_forwardTutorial A radio broadcast left Earth in 1923. How far in light years has it traveled? If there is, on average, 1 star system per 400 cubic light years, how many star systems has this broadcast reached? Assume that the fraction of these star systems that have planets is 0.50 and that, in a given planetary system, the average number of planets that have orbited in the habitable zone for 4 billion years is 0.40. How many possible planets with life could have heard this signal? Part 1 of 3 To figure out how many light years a signal has traveled we need to know how long since the signal left Earth. If the signal left in 1923, distance in light years = time since broadcast left Earth. d = tnow - broadcast d = 97 97 light years Part 2 of 3 Since the radio signal travels in all directions, it expanded as a sphere with a radius equal to the distance it has traveled so far. To determine the number of star systems this signal has reached, we need to determine the volume of that sphere. V, = Vb…arrow_forwardThe Pioneer 10 spacecraft has left our Solar System and is traveling at a speed of 45,000 km/h (andhas been doing so for years). Explain why this object is moving so fast although it ran out of fuel longago.arrow_forward
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