Intro to Airspace HW

The HW is so easy level and it should be solved in the file I attached.

Thanks you.

SPS1020: Intro to Space Sciences
Homework #1
Due Tuesday, September 26, at the beginning of class (11:00 a.m.)
Instructions:
It is beneficial to read over this assignment and look at the questions as soon as you receive it.
You should begin work on it early, as it will be difficult/impossible to get help from me in the
last 2-3 hours before it is due. If you tend to procrastinate, pretend like it is due on Monday
morning (i.e., do it Sunday night).
The majority of the instructions for this assignment are in the Instructions for Submission of
Problem Sets Handout that is available on CANVAS or by request. Please read that information
carefully before starting. Keep in mind that it is not a requirement to type up the answers but you
should write neatly, clearly identify page and question numbers, use words to briefly explain
your reasoning, show your work, use scientific notation with the appropriate amount of
significant digits, and box your answers. If I can’t read your homework, I can’t give you points.
If you need to find some data (diameters, distances, orbital periods, etc.), please cite your
sources. You may use any reasonable assumption in your solution that you briefly justify in
writing. Note that the statement “I assumed that the solution is X” is not a reasonable
assumption.
Collaboration is allowed if you adhere to the following steps. 1) Try all the problems yourself
first. 2) Meet with a small group of other students and discuss questions you had difficulty with.
3) Work together to develop your personal understanding of how to solve the problem. 4) Write
up your own completely independent solution in your own words and equations. 5) List all
collaborators on your problem set write-up.
The homework solutions need to be submitted via canvas, as a single pdf file. Late submissions
will not get accepted (see the syllabus) without a pre-arranged approval in the case of serious
extenuating circumstances.
Questions
1) Imagine that you could drive your car at a constant speed, even across oceans and in space.
(a) How long would it take to drive around Earth’s equator on the Equatorial Highway? (speed
limit 70mi/hr)
(b) How long would it take to drive from the Earth to the Moon with the same speed?
(c) How long would it take to drive from the Sun to Mars on the Planetary Freeway? (speed limit
of 700 mi/hr)
(d) How long would it take to drive to the nearest star, Alpha Centauri, that is 4.4 light-years
away using the Interstellar (not the movie) Expressway that has a speed limit of 7000 mi/hr?
2) Humankind is planning its first trip to Mars. Roughly what is the distance (in everyday
“units’’) between Earth and Mars on the 1-to-10 billion scale described in Section 1.1 (or see
lecture slides)?
3) About how many times larger is the diameter of the Milky Way Galaxy than the diameter of
Neptune’s rings? Feel free to use Google to find the sizes of these two objects.
4) The cosmic calendar of Section 1.2 in the Cosmic Perspective (section 1.9 in the OpenStax
book) explains where we are in the universe in time. But time and space are connected through
the speed of light. How far could light travel in 1 hour of the “cosmic calendar” in light-years?
What astronomical object in Figure 1.1 (Cosmic Perspective, or see “Cosmic Address” lecture
slides) is approximately this size?
5) Section 1.3 and Figure 1.16 in the Cosmic Perspective (figure 26.17 on p893 in the OpenStax
book, or see lecture slides) describe the Raisin Cake analogy for understanding why a uniform
expansion of the universe appears as if all galaxies are moving away and more distant galaxies
are moving faster. Consider Raisin #2 away from the “Local Raisin”, which had a distance
before baking of 3 cm and after baking of 9 cm. Let’s say you accidentally forget to turn the
oven off and the cake expands by another factor of 3 after another hour. How far away is Raisin
#2 now? Comparing the rough average speed during the first hour and the rough average speed
during the second hour, did its speed seem to increase, decrease, or stay the same?
6) The textbooks claim that astronomy and technology develop hand-in-hand.
(a) Verify this by identifying one example of an astronomy computer software (can’t use
Stellarium).
(b) Find an astronomy app that could be installed on your mobile device that looks interesting to
you (you don’t need to install anything if you don’t want to). Or you can use a Google to search
for free astronomy software and list a software program that looks interesting to you
(c) Briefly describe (no more than two sentences) what was the appeal of this particular app, why
did it seem interesting.
7) You are standing on the surface of Jupiter’s moon, Europa (wouldn’t that be awesome). If
you’re looking at Jupiter from there, what is the planet’s angular size? How big (in terms of
angular size) would the Sun look from the surface of Europa?
8) Estimate the diameter of the supergiant star Betelgeuse, using its angular diameter of about
0.05 arcsecond and distance of about 600 light-years. Compare that diameter to the size of the
Sun; which one is bigger and how many times bigger? Compare the Diameter of Betelgeuse to
the average distance between the Earth and the Sun.
9) You stay up all night on the roof of the Olin Physical Sciences building watching the stars and
find one star that doesn’t seem to move. What is the approximate azimuth and altitude of this
unmoving star?
10) What zodiacal constellation is the most visible all night long on September 21. (Like many
questions, you can solve this using a figure from the book or from the lecture slides.) Briefly (1-2
sentences) justify your answer.
11) When it is the hotter part of the year (i.e., summer) in the Northern hemisphere (of Earth), is
it the colder part of the year in the Southern hemisphere? Mercury has no axis tilt, but a very
eccentric orbit (i.e., at times it is much closer to the Sun than at other times. We will learn about
this in details in the upcoming weeks). When it is the hotter part of the year in the Northern
hemisphere of Mercury, is it the colder part of the year in the Southern hemisphere? Explain
your answer in 2-3 sentences.