Jovian Joviality: Juno is a Healthy Spaceship, On-Track for 2016 Jupiter Rendezvous

Artist's impression of the Juno flyby (NASA)
Artist’s impression of the Juno flyby (NASA)

Last week’s Juno flyby of Earth was an exciting event. NASA’s Jupiter-bound mission buzzed our planet on Wednesday (Oct. 9) only 350 miles from the surface, providing amateur astronomers with an opportunity to snapshot Juno as she flew past, stealing a little momentum from Earth and sling-shotting toward the largest planet in the Solar System. Alas, the flyby event wasn’t without incident.

The spacecraft dropped into “safe mode” shortly after its terrestrial encounter. Safe mode is a fail safe on spacecraft that protects onboard instruments from an unexpected condition. This can come in the form of a power spike or some other instrumental error. It is not known at this time what triggered this particular event, but the upshot is that Juno is back in its nominal state.

From a Southwest Research Institute news release:

“Onboard Juno, the safe mode turned off instruments and a few non-critical spacecraft components, and pointed the spacecraft toward the Sun to ensure the solar arrays received power. The spacecraft acted as expected during the transition into and while in safe mode.”

Juno’s planned trajectory was not impacted during the flyby and it is expected to make orbital insertion around Jupiter in July 2016.

The mission was launched from Cape Canaveral, Fla., in 2011 and, through a wonderful bit of orbital mechanics, was commanded to do one 2-year orbit around the Sun. Then, last week, it ended up where it started to use our planet as a speed booster, flinging it further out into the Solar System toward Jupiter’s orbit. This acceleration “freebie” was needed as the launch vehicle, an Atlas V rocket, didn’t have the oomph to propel the spacecraft deeper into space.

Once Juno arrives at Jupiter, it will give the gas giant a thorough full-body examination, investigating what lies beneath its clouds, how it generates its powerful magnetic field and how it evolved. The repercussions of Juno’s one-year primary mission will hopefully expose not only how Jupiter is formed, but how Earth evolved into its current state.

As Juno sped past on Wednesday, I allowed myself an early celebration of some fine flying by NASA scientists with a Gin & Tonic (or a Juno & Tonic) in my special JPL-bought Juno glasses.

Good luck Juno, will look forward to seeing you at Jupiter in a little under three years time!

MORE: Read my Discovery News post about the possibility of Juno exhibiting the mysterious “flyby anomaly.”

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Amateur Captures Solar Eclipse, By Io… On Ganymede

io-ganymede-shadow-still

Of all the amazing things I plan to look at through my future telescope (yes, I’m still saving), this event didn’t even cross my mind. Not surprising really, it’s probably never been observed before: Io’s whole shadow transiting across the large Jovian moon, Ganymede.

But on August 16th, that changed when Christopher Go from Cebu, Philippines used his 11-inch Celestron telescope to capture the sequence of events as Io passed in front of the Sun, casting a near-perfect shadow on the large moon of Ganymede. If you were standing on Ganymede’s surface, looking at the Sun, you would have seen an Io solar eclipse.

io-gann-eclipse

My favourite thing about this animation is that both moons are very detailed, even at this resolution. You can see mottled shades on Ganymede, and I think the spin of Io may even have been captured.

A wonderful testament to Christopher Go’s astronomy skills and a fantastic example of how advanced our amateur astronomical equipment is becoming…

Source: Spaceweather.com

UPDATE: It turns out that little Io is getting its own back for last July’s eclipse by Ganymede, plunging the smaller moon into darkness. In the following video by OccultDave on YouTube, over a period of about 16 minutes, Io (the dot to the far-right) dims dramatically as Ganymede (the dot in the middle, next to the bright disk of Jupiter) blocks the sunlight:

Brown Dwarfs: “Over-Achieving Jupiters” not “Failed Stars”

browndwarf3

Why is the term “failed star” synonymous with brown dwarfs? On the one hand, brown dwarfs lack the mass to sustain nuclear fusion in their cores. On the other hand, who said brown dwarfs were trying to be stars? Who ever said that becoming a star was the pinnacle of stellar living? Perhaps brown dwarfs are perfectly happy the way they are. In a world of equality and political correctness, brown dwarfs could be viewed as “over-achieving Jupiters”, or gas supergiants
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Astroengine Interview with Dr Richard Greenberg: “Unmasking Europa”

A future mission to the Jovian moon Europa could incorporate a life-searching robotic submersible under the icy crust (NASA)
A future mission to the Jovian moon Europa could incorporate a life-searching robotic submersible under the icy crust (NASA)

On Wednesday (Feb. 18th), NASA and ESA decided to “prioritize” a mission to Jupiter. Set to be launched in 2020 (for a 2026 arrival in the Jovian system), NASA will work on a spacecraft called the Jupiter-Europa mission and ESA will work on the Jupiter-Ganymede mission. Both probes will be launched at the same time to carry out this unprecedented planetary mission. However, this doesn’t mean a mission to Saturn will be off the cards; NASA hinted that a return trip to the ringed gas giant will also be planned in tandem (following in the footsteps of the Cassini Equinox Mission). But Jupiter comes first.

In an enlightening interview earlier today, Dr Richard Greenberg, an eminent Europa scientist, discussed this recent NASA/ESA announcement with Astroengine Live and his excitement that there will be a return mission to the Jovian system. He is an expert in celestial mechanics and worked on several NASA projects at the University of Arizona’s Lunar and Planetary Laboratory. Dr Greenberg has also published a book called “Unmasking Europa” (of which I am very excited to receive a copy soon), detailing the science under the icy crust of the moon, where there is a tantalizing possibility life may thrive in tidally-heated sub-surface oceans.

But that’s not the best part. Dr Greenberg provides an exciting narrative about what form this Europa (European?) life may take… It’s not just microbial extraterrestrials that could survive in these environments

Be sure to listen in to my radio show, Astroengine Live on Wednesday, February 25th to hear the full recording of my conversation with Dr. Richard Greenberg.

Moon, Venus, Jupiter Conjunction Dazzles California

Tonight is a very special night. Three celestial bodies clustered together in the sky, signifying a rare conjunction between the Moon, Venus and Jupiter. If you missed it, you’ll have to wait five years until the natural satellite of the Earth and two planets align in a similar pattern again in 2013.

Having been a frustrated astronomer for many years, I decided to get outside to investigate the conjunction over California for myself. Sure enough, from dusk, I could see a bright, thin crescent Moon with two very bright dots to the right and below in the southwest. The same scene has been repeated across many nations, but from my perspective I was able to capture the moment with some basic equipment and a very steady hand (plus some folded business cards)…
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