Asteroid Parallax
(Lab #2 - I know, it’s
confusing and weird)
February 23rd, 2016
Steve Mairs
So, how big would an asteroid have to be to
strike the earth and cause a global extinction?
Since the birth of our solar system,
only 42 collisions in asteroid belt
Goals of the day
1. Using 2 images and the power of thought - find the
distance to a Near Earth Asteroid!
2. Using a third image, find the speed it was traveling!
3. Calculate the size of the asteroid
using the wonders of math!
4. Leave the lab knowing a bit more about Linux
Parallax
Victoria!
Winnipeg!
Task Set #1!
1.
Measure X and Y for 10 stars in both the Victoria and Winnipeg Images
2.
Measure the X and Y for the Asteroid in both the Victoria and Winnipeg Images
3. Find the average X and Y Offset (from stars - just subtract)
4.
Find the Parallax angle of the Asteroid (Pixels x 1.997)
5. Measure the same 10 stars in the Second Victoria Image
6.
Measure the Asteroid in the Second Victoria Image
Finding the Distance from Parallax
D >> d
How do we find “d”
(linear distance from Victoria to Winnipeg)?
W
d
V
R48
Known
Angle!
R48
TOP DOWN!
How do we find “d”
(linear distance from Victoria to Winnipeg)?
R48
Re
48
Re
Side View of the Earth!
How do we find “d”
(linear distance from Victoria to Winnipeg)?
W
d
V
R48
Known
Angle!
R48
TOP DOWN!
Task Set #2!
1. Find the distance to the asteroid
The Size of the Asteroid
We use the flux!
There is a well-known formula
to convert from apparent
magnitude to relative flux!
And the flux just depends on
the distance and the radius!
Using a reference is a cheap
astronomy trick
Task Set #3!
1. Using your calculated distance the asteroid
and the radius and flux of the moon,
find the size of the asteroid
The Speed of the Asteroid
Images 10
minutes apart!
Task Set #4!
1. Find the Speed of the Asteroid
2.
Go Home ;p
https://www.youtube.com/watch?v=90Omh7_I8vI