"That's a good question" as they say. And the answer is "It depends" ...on the local time directly below GOES, the Sun's latitude when viewed from the Earth, and where on the Earth the observer is stationed. X-rays travel at the same speed as all electromagnetic waves - 300,000 kilometres per second in round figures. The time difference depends mainly on the difference in the distance between the Sun and the Earth, and the distance between the Sun and the GOES. Again, using round figures and dealing with the simplest case of a zero inclination orbit at the time of an equinox, it will vary between -36,000 kilometres and +49,000 kilometres in a 24 hour cycle, as GOES moves along its orbit. When it is local noon at the sub-GOES point, the satellite will see the x-rays about 0.12s before they hit any point on the Earth. when it is midnight, then GOES will see the x-rays about 0.16s after they first hit any point on the Earth. These are two simple scenarios, there are many other answers covering the scenarios in between. And of course..... there are multiple GOES in different locations. Bob Christy Thomas Ashcraft wrote: > I have a math question for anyone here: > > The GOES satellites monitor X-rays from the Sun. What would be the > difference in time ( a matter of seconds?) between when solar x-rays > hit the GOES sats and then hit the surface of the Earth? > > I hope the question is clear and if not I will re-ask. > > Thanking you in advance for your reply. > > Thomas Ashcraft > New Mexico > > > ------------------------------------------------------------------------- > Subscribe/Unsubscribe info, Frequently Asked Questions, SeeSat-L > archive: http://www.satobs.org/seesat/seesatindex.html > > ------------------------------------------------------------------------ > > > No virus found in this incoming message. > Checked by AVG - www.avg.com > Version: 8.0.233 / Virus Database: 270.10.23/1949 - Release Date: 02/11/09 18:11:00 > > ------------------------------------------------------------------------- Subscribe/Unsubscribe info, Frequently Asked Questions, SeeSat-L archive: http://www.satobs.org/seesat/seesatindex.html
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