Monday, October 10, 2016

It's been a year since NASA said that Pluto is not a planet and now we have the pictures. How long does it take to get that data?

NASA had nothing to do with demoting Pluto from being a planet to being a dwarf planet.

The signal from New Horizons travels at the speed of light.  The spacecraft is about 32 AUs (astronomical units) from Earth.  That means it is 32 times farther away from the Earth than the Sun is from Earth.  It takes sunlight about eight minutes to reach Earth.  Multiply that out by 32 and we can see that it takes about 4 hours and 25 minutes for a signal to travel from New Horizons current location to the receiving antennae on Earth.

But that doesn't mean an image reaches Earth 4 hours and 25 minutes after it was taken.  At New Horizon's great distance, it has to transmit at a very low data rate to keep the signal quality acceptable.  New Horizons can transmit the data at about 1000 bits per second.  That means it takes about 45 minutes to send back one picture.

So, as New Horizons flew past Pluto it took as many images and instrument readings as it could and stored all of that information on solid state recorders.  It will slowly trickle all of that information back to Earth over the next 16 months or so.  The process is not continuous, because sometimes there isn't a good line-of sight and sometimes the vehicle needs to send other data.


Read other answers by Robert Frost on Quora: Read more answers on Quora.

from Quora http://ift.tt/2dYTFQF

No comments:

Post a Comment