Where were you on the 5 August 2011? This day has no special meaning to me so I have no clue what I was doing. For NASA, this day was the start of a very long journey for the Juno spacecraft. Juno will arrive at its destination on 4 July 2016. That is 1,794 days since Juno was launch into space. All this time Juno has been cruising along at about 14,400 miles per hour. As Juno nears Jupiter, it will accelerate to 144,000 miles per hour due to Jupiter’s gravitational pull. NASA will use Juno’s rocket engines to slow the spacecraft so that it can enter orbit around Jupiter. I don’t know about you, but a trip that is just shy of five years is a really long time.
To put all of this into perspective, the distance from Earth to Jupiter, when the two plants are closest to each other, is 365,000,000 miles.
A round trip flight from San Francisco to London is 10,703 miles. One would have to fly 34,106 round trip flights to equal the distance from Earth to Jupiter. Here on Earth, a round trip flight takes about 20 hours and 40 minutes to complete. One would have to spend 80.5 years flying between San Francisco and London, non-stop, to equal the distance to Jupiter at the average cruising speed of a passenger jet. Juno has been flying really fast to complete this journey in just under five years.
Most people are familiar with the great red spot on Jupiter (lower left in the picture above). Three plants the size of the Earth can fit inside this persistent anticyclonic storm. So not only is Jupiter a long ways away, but it is also a really big planet. Over the next several weeks, Jupiter will be one of the brightest objects in the night sky, not including the moon. If you are feeling small after reading this post, you are not alone.