Ahem. Regular readers well-know how these interplanetary space science events fire our imagination, here. [Just one of our prior stories on Juno is here. Use the search box above, for the rest -- another ten or fifteen of them.]
So it is that on Sunday morning (tomorrow, around 8 AM local -- as imaged by faded half-tones, at right, in the disks), the lilting, long-legged Juno, a twisting copper-colored shepherded moonlet (of sorts), will once again dip dangerously close to the Jovian North Pole, and brave perhaps the most daunting space environs a spacecraft has ever encountered inside our solar system (save only a brush against the sun itself).
She will be moving extremely fast, as fly-bys go, at 129,000 miles an hour (to minimize time in the danger zone, and not get trapped in a gravitational death spiral), enduring crazy hot radiation @ 20 million RAD; a magnetic field 20,000 times stronger than Earth's -- coming rapidly out of minus 280 degrees Fahrenheit, straight into an unimaginably vast and powerful microwave oven, on full-blast. "Charred on the outside, frozen on the inside," indeed.
All of this, some 520 million miles away from any possible Earth-based software repair (and thus a 48 minute lag -- at the speed of light, for commands to be received). So, as she speeds past this third time, she will leave one of her eight instruments off (needing a software update, not yet completely uplinked across the 500 million mile expanse -- by radio frequency). But the other seven will be. . . on, and recording. We will be keeping a good thought -- that her graceful copper-colored limbs aren't fried by the radiation, or fouled by the magnetic storms, as she collects data on what Jupiter hides beneath those occluding cloud-tops. [We now know there is a thick layer of hydrogen, but at the pressures created by Jupiter's great mass, that hydrogen is thought to be a metallic liquid. We cannot "make" metallic liquid hydrogen on Earth, as we lack a pressure cooker powerful enough to achieve it. But what a sight that swirling silvery grayish ocean of molten metallic hydrogen would be. . . wow. But I digress.]
Here's a bit, from NASA, this clear cold Saturday morning:
. . . .On Sunday, December 11, at 9:04 a.m. PST (12:04 p.m. EST, 17:04 UTC) NASA’s Juno spacecraft will make its third science flyby of Jupiter.
At the time of closest approach (called perijove), Juno will be about 2,580 miles (4,150 kilometers) above the gas giant’s roiling cloud tops and traveling at a speed of about 129,000 mph (57.8 kilometers per second) relative to the planet. Seven of Juno’s eight science instruments will be energized and collecting data during the flyby.
"This will be the first time we are planning to operate the full Juno capability to investigate Jupiter's interior structure via its gravity field,” said Scott Bolton, principal investigator of Juno from the Southwest Research Institute in San Antonio. “We are looking forward to what Jupiter’s gravity may reveal about the gas giant's past and its future.”
Mission managers have decided not to collect data with the Jovian Infrared Auroral Mapper (JIRAM) instrument during the December flyby, to allow the team to complete an update to the spacecraft software that processes JIRAM’s science data. A software patch allowing JIRAM’s operation is expected to be available prior to the next perijove pass (PJ4) on Feb. 2, 2017. . . .
It will take several weeks to download all the data, but we fully expect much new astro-physical science will be understood, even a year from now, about how Jupiter does. . . what it does -- 'tis jaw-slacking, indeed. Closer to home, I am quite excited to be hosting an old college roomie here in the city this weekend -- galleries, museums and dining ahead. Smile. . . .