measuring the size of jupiter’s great red spot from your backyard

7/25/2019 Measuring the Size of Jupiters Great Red Spot From Your Backyard

1/13

Measuring the Size of Jupiters G

Red Spot from your Backyar

Mehdi Bozzo-Rey ([email protected]), January 2016
mailto:[email protected]:[email protected]:[email protected]


2/13

Why Jupiter ?

fed as a kid with Voyager, Galileo, HST images

structures, satellites Jupiter is a very vast moving world on its

Mehdi Bozzo-Rey: [email protected]

Voyager-Credit NASA/JPL Caltech,

1979

Galileo - Credit NASA/JPL Caltech,

1997

HST - Credit
http://hubblesite.org/newscenter/archive/releases/2008/27/http://photojournal.jpl.nasa.gov/catalog/PIA00489http://voyager.jpl.nasa.gov/gallery/images/jupiter/redspotx.gif


3/13

Background

Observe, measure and think about it !

Data acquisition is one thing, but what can we do with it ? measurement

Amateur astronomy and amateur science



4/13

Can I really add something with my C8 ???

The thing is I only have a C8 and a DSLR C8

CANON EOS 6D

Skywatcher AZ-EQ6 Powermate 2.5x

Backyard EOS

The SkyX Pro

EQ-MOD

Registax6

PixInsight

My great dark site does not add anything

Luck helps for events (triple transit)

Do I need more aperture ? something that includes 16 and SCT in the product name ?



5/13

Back to basics: optical system



6/13

What do I know and what do I need to calcu

Backyard EOS in planetary mode with my DSLR: 1:1 mapping (o

= one pixel) D: distance earth planet

Sccd: size on the CCD sensor. Pixel pitch: 6.5 micrometers in m

Sp: planet size

f: focal length of the ENTIRE optical train

Are the values from the vendors to be trusted ? How to deal with my Powermate ?



7/13

First attempt: polar and equatorial diameters

My old greek friends tell me that:

So

or



8/13

First surprise using vendor values for f

Cant find the right value for the polar diameter (142984 kms) !

What does that mean ? I am off few pixels

vendor values for f are slightly wrong and I am more around 2x than 2.5x for

Mehdi Bozzo-Rey: [email protected] televue powermates specifications
http://www.televue.com/engine/TV3b_page.asp?id=53&Tab=_apphttp://www.televue.com/engine/TV3b_page.asp?id=53&Tab=_app


9/13

Second surprise: where does the GRS stop


987 kms per pixel


10/13

PixInsight and range selection

generates a mask by defining a range of pixel values

close the loop !



11/13

I do believe in statistics !

calculation done on the 13 pictures

and averaged

final values: 16587 kms (equatorial)

and 10020 kms (polar)

Value measured by NASA (equatorial)

using HST data in 2014: 16500kms



12/13

What did I learn ?

Always good to have old friends from Greece

How to insert math equations in my Google presentations

Real life introduction to mathematics, astronomy, and scientific p

kids : success !

A small C8 can produce scientifically viable data when coupled

software

When you do send emails to NASA scientists, they do respond

I can measure planetary objects from my backyard !

More details:

Diameter measurement

GRS measurement

https://bozznet.wordpress.com/2015/03/22/measuring-jupiters-great-red-spot-from-your-backyard/https://bozznet.wordpress.com/2015/03/22/measuring-jupiters-great-red-spot-from-your-backyard/https://bozznet.wordpress.com/2015/03/03/jupiter-equatorial-diameter-measurement/


13/13

Next steps

Focal length (or equivalent) is available for all the scientific instru calculations using HST /other cameras

Lets introduce time in the equation

gives access to speed

Projects: speed of different bands

size of SL9 impacts (HST, Galileo) speed of the shockwave for SL9 impacts ? (HST)

size of Saturns hexagon (CASSINI)


measuring the size of jupiter’s great red spot from your backyard

Documents