Science

PSC 1210, Assignment 8 Name ____________________

Due Nov 1st , Midnight

The Scale of Space, Habitable Zones and Exoplanets (24 pts)

A. The scale of space. (8 points)

Using the discussion and formulae presented in class, calculate the following (if you want part credit, I would recommend showing your work). Also try and convert seconds into a more meaningful unit. For example, there are 3600 seconds/hour, 86400 seconds/day etc etc):

1. At the speed of the New Horizons space craft, how long for it to go from NY to San Francisco? (might need Google Earth to get the distance from NY to San Fran)

2. At the speed of the New Horizons space craft, how long for it to go from the Earth to the moon?

3. How long for it to go from Earth to the Sun (if we sent it on a suicide mission!)

4. How long will it take to reach the nearest star?

B. Scaling the Habitable Zone (4 points)

Open the Habitable Zone Scaling Tool (an XLS file)

You should see a yellow dot in the middle with two dashed green circles surrounding it. As the slide says (lower right hand side). The habitable zone is in between these circles. Then things to play with:

The relative luminosity, in blue at the top. The arrows next to it make it go up or down.

The orbits of Earth Venus and Mars- boxes on the right which you can check or uncheck.

PSC 1210 Assignment 8, page 2 Name ______________________

Habitable Zone scaling, continued

1. With the orbit boxes unchecked…. Just practice scaling the sun’s luminosity between 0.5 to 2.0. What does the habitable zone do as you go from 0.5 to 2.0?

2. Then check all three orbit boxes. With the luminosity set to 2.0, what planet or planets are in the habitable zone?

3. With the luminosity set to 0.5, what planet or planets are in the habitable zone?

Feel free to add any explanation if you think it’s hard to tell. (optional)

C. Go to the Exoplanet Catalog: https://exoplanets.nasa.gov/exoplanet-catalog/ (12 points)

Scroll down. Look on the right side, under where it says Planet Type.

1. What is the most common type of exoplanet seen so far?

2. Then go to “Search” and type “Proxima”. You should see one entry.

a. What category is this? Is this planet closer to Earth in size or to Neptune or Jupiter?

b. Compared to general distances in the galaxy discussed in class, is this star close or far away?

3. Click where it says Proxima B in blue on the left. You will see a hypothetical artist conception. Look at the data underneath the image (“orbital radius” means distance from the star). Compared with planets in our solar system, where does this planet’s orbit lie?

PSC 1210 Assignment 8, page 3 Name ______________________

4. Click on the eye in the blue box on the right. And select star and the click the box again to compare with sun. What do you see? How does Proxima Centauri compare with our sun?

5. How does your expectation for the habitable zone for Proxima Centauri square with the distance of Proxima Centauri b from the star. Could it be in the habitable zone- yes, no or maybe? They key is to justify your answer based upon what you know about stellar luminosity.

6. Extra credit for a point (its extra credit because the web page may be buggy). Go back and start over, but this time when you hit the blue box hit “compare with system”. You’ll have to zoom out (like you would do on Google Earth or Google Maps) and what do you see?