Juno swings back towards Jupiter

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Juno has now passed the farther point from Jupiter in its first orbit and has started dropping back down to the gas giant.

Juno arrived at Jupiter on July 4, firing its main rocket engine as planned for 35 minutes. The flawless maneuver allowed Jupiter’s gravity to capture the solar powered spacecraft into the first of two 53.4-day-long orbits, referred to as capture orbits. Following the capture orbits, Juno will fire its engine once more to shorten its orbital period to 14 days and begin its science mission.

But before that happens, on Aug. 27, Juno must finish its first lap around Jupiter, with a finish line that represents the mission’s closest pass over the gas giant. During the encounter, Juno will skim past Jupiter at a mere 2,600 miles (4,200 kilometers) above the cloud tops.


  • Alex

    I do not see the necessary for those “capture orbits”. Waste of time (about 82 days).

  • Localfluff

    Juno will at perijove be about 10 times as far from Jupiter as the ISS is from Earth. But Jupiter has 11 times the diameter, so an image of Jupiter from Juno then will be like an image of Earth from the ISS. Only a small part of Jupiter will be visible at once. The link below shows a great image of the Great Red Spot, taken by the Galileo orbiter 20 years ago (imaging technology has improved a great deal since then). From 1,500,000 km distance (four Lunar distances). Let’s see how it looks when 300 times closer!

    And Juno will sometime end its mission by crashing into Jupiter. That’ll show us some alien cloud tops. The Galileo probe could not send any images from its crash down. Because its main antenna never unfolded, it did not have time to transmit image data during the descent. And Cassini will crash into Saturn late next year.

    When one looks into such decisions like orbital insertions, one always finds that they have good reasons. I suppose they could’ve made both the burns at the same time. One reason I’ve heard is that they need these first 50 days or so to calibrate the instruments anyway. It carries unique magicians wands and potions and has never been done before, so the sorcerer’s apprentice needs to adjust to the new world it now is at, before the spells cast will work.

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