How long would it take light from the sun to reach Ceres?

1 Answer
Nov 5, 2016

Somewhere between #1276# and #1486# seconds.

Currently (2016-11-05) #1433# seconds.

Explanation:

Ceres distance from the sun varies between #3.8262 xx 10^11 "m"# at perihelion and #4.4541 xx 10^11 "m"# at aphelion.

As I write, it is at about #4.297 xx 10^11 "m"#

The speed of light in vacuum is #2.99792458 xx 10^8 "ms"^(-1)#

So at perihelion it would take:

#(3.8262 xx 10^11) / (2.99792458 xx 10^8) ~~ 1276# seconds

and at aphelion it would take:

#(4.4541 xx 10^11) / (2.99792458 xx 10^8) ~~ 1486# seconds

At this time of writing it would take:

#(4.297 xx 10^11) / (2.99792458 xx 10^8) ~~ 1433# seconds