Daily Archives: August 13, 2013

Juno Halfway to Jupiter

Cartoon depiction of Juno's location enroute to Jupiter.  Click for expanded view. Credit: NASA
Cartoon depiction of Juno’s location enroute to Jupiter. Click for expanded view. Credit: NASA

Yesterday at 12:25 UTC the Juno spacecraft marked the halfway point in its journey to Jupiter. The odometer just turned 1,415,794,248 km or 92,955,807.273 miles. In easier numbers its 9.464 astronomical units. Since one astronomical unit is the mean distance from the Sun to Earth ( 149,597,870.7 km / 92,955,807.3 miles) you would think it would be a lot further away than it appears in the cartoon depiction of Juno’s flight path. In fact you could make the argument that Juno it appears, is closing in on planet Earth!

You would be correct, Juno was only 55.46 million km / 34.46 million miles away and approaching. Although the cartoon is a little dated, it was approxiamtely accurate on 8 Aug 13, just a few days ago. So what’s going on? Mission managers plotted out a circuitous route that takes advantage of an Earth gravity assist and that is coming in October when on the 9th when it will fly by at just 559 km (337 miles)! The flyby will increase the velocity of Juno by 7.3 km/sec or 1,330 mph. Two years later Juno arrives at Jupiter.

To get a nice overview of what Juno is going to be doing once it gets to Jupiter check out the NASA webpage:  Juno Mission to Jupiter: Unlocking the Secrets of a Giant Planet.

You can get map updates from Eyes on the Solar System.