The discovery of dark oxygen at an abyssal plain on the ocean floor generated a lot of interest. Could this oxygen source support life in the ocean depths? And if it can, what does that mean for places like Enceladus and Europa?
Launched on April 14, 2023, the European Space Agency’s (ESA) Jupiter Icy Moons Explorer (Juice; formerly known as JUICE) spacecraft has finally completed the unfurling of its solar panel arrays and plethora of booms, probes, and antennae while en route to the solar system’s largest planet.
A new era of exploration at Jupiter’s moons began last week with the launch of the European Space Agency’s Juice, the Jupiter Icy Moons Explorer. This mission will visit three of Jupiter’s largest moons — Europa, Callisto and Ganymede — to investigate whether they could be potentially habitable, a question that’s been highly debated since the first evidence of subsurface oceans on these moons was seen by the Galileo mission in the 1990s.
Jupiter is well known for its spectacular aurorae, thanks in no small part to the Juno orbiter and recent images taken by the James Webb Space Telescope (JWST). Like Earth, these dazzling displays result from charged solar particles interacting with Jupiter’s magnetic field and atmosphere. Over the years, astronomers have also detected faint aurorae in the atmospheres of Jupiter’s largest moons (aka. the “Galilean Moons“). These are also the result of interaction, in this case, between Jupiter’s magnetic field and particles emanating from the moons’ atmospheres.
Detecting these faint aurorae has always been a challenge because of sunlight reflected from the moons’ surfaces completely washes out their light signatures. In a series of recent papers, a team led by the University of Boston and Caltech (with support from NASA) observed the Galilean Moons as they passed into Jupiter’s shadow. These observations revealed that Io, Europa, Ganymede, and Callisto all experience oxygen-aurorae in their atmospheres. Moreover, these aurorae are deep red and almost 15 times brighter than the familiar green patterns we see on Earth.
Now less than one year until the projected launch date, ESA’s JUICE mission is in the final phases of development. The JUpiter ICy moons Explorer (JUICE) is now fully built with all ten instruments integrated into the spacecraft bus. Next comes all-up testing in a full flight configuration.
Launch is currently scheduled for April of 2023, with the mission slated to conduct detailed investigations of Jupiter and its system of moons, focusing on Europa, Callisto and especially Ganymede.
Is there a more complicated and sophisticated technological engineering project than a spacecraft? Maybe a particle accelerator or a fusion power project. But other than those two, the answer is probably no.
Spacecraft like the ESA’s JUICE don’t just pop out of the lab ready to go. Each spacecraft like JUICE is a singular design, and they require years—or even a decade or more—of work before they ever see a launch pad. With a scheduled launch date of 2022, JUICE is in the middle of all that work. Now its cameras are capturing images of Jupiter and its icy moons as part of its navigation calibration and fine-tuning.
Missing Jove? The largest planet in our solar system is currently on the far side of the Sun and just passed solar conjunction on September 26th, 2016. October now sees Jupiter slowly return to the dawn sky. Follow that gas giant, as an interesting set of double shadow transits transpires in late October leading in to early November.
This particular cycle of double shadow transits involves the large Jovian moons of Europa and Ganymede.
Europa and Ganymede double shadow transit season begins later this month, as both cast shadows on the Jovian cloud tops. This series of simultaneous shadow transits runs from October 17th to November 8th, and includes four weekly events.
The inner three large moons Io, Europa and Ganymede are in a 4:2:1 resonance. Europa orbits Jove once every 3.6 days and makes two circuits for Ganymede’s one. This means there’s a double shadow transit once every week in the current season:
When can you first spy Jupiter, post solar conjunction? Catching this particular series of double shadow transits is challenging this time around, owing to the planet’s position low in the dawn twilight. The first event on October 17th starts with Jupiter just 16 degrees west of the Sun, and the cycle ends with Jove 38 degrees west of the Sun on November 8th.
Keep in mind, it is possible to track Jupiter up in to the daytime sky, post sunrise. To do this, you’ll need a ‘scope with a solid equatorial mount and good sidereal tracking. The trick is to lock on to Jupiter before sunrise and track it up in to the dawn sky. Be sure to physically block that dazzling rising Sun out of view behind a hill or building, and NEVER aim your telescope at the Sun!
Using this method opens up the possibility of nabbing a given double shadow event to longitudes due east of the quoted locales above.
The waning crescent Moon also passes 1.4 degrees NNE of Jupiter on October 28th, offering another chance to spy the gas giant in the dawn sky, using the nearby crescent Moon as a guide.
And another interesting pairing is coming right up on the morning of Tuesday, October 11th, when Mercury passes just 0.8 degrees (48′) NNE of Jupiter. Both are only 12 degrees west of the Sun at closest approach, which occurs around 10:00 UT. Still, both will appear as an interesting pseudo-double star, with Mercury shining at magnitude -1.1 and Jupiter only half a magnitude fainter at -1.6.
You can even see Jupiter coming off of solar conjunction and headed toward dawn skies courtesy of SOHO’s LASCO C3 camera:
Callisto, the outermost large moon of Jupiter, ceased casting its shadow on Jupiter earlier this year on September 1st 2016. Callisto is the only large moon that can ‘miss’ the gas giant’s cloud tops. Callisto must be involved for a triple shadow transit to occur, and the moon resumes regularly casting its shadow on Jove on December 4th, 2019.
Callisto can also experience total solar eclipses similar to those seen from the Earth during the mutual eclipse season for Jupiter’s moons, albeit shorter in duration:
And don ‘t forget: we’ve got a spacecraft currently exploring Jupiter for the next year and a half: NASA’s very own Juno.
Be sure to check out the Jovian action over the next month, gracing a dawn sky near you.
Now just 7 days out from a critical orbital insertion burn, NASA’s Jupiter-boundJuno orbiter is closing in fast on the massive gas giant. And as its coming into focus the spacecraft has begun snapping a series of beautiful images of the biggest planet and its biggest moons.
In a newly released color image snapped by the probes educational public outreach camera named Junocam, banded Jupiter dominates a spectacular scene that includes the giant planet’s four largest moons — Io, Europa, Ganymede and Callisto.
Junocam’s image of the approaching Jovian system was taken on June 21, 2016, at a distance of 6.8 million miles (10.9 million kilometers) and hints at the multitude of photos and science riches to come from Juno.
“Juno on Jupiter’s Doorstep,” says a NASA description. “And the alternating light and dark bands of the planet’s clouds are just beginning to come into view,” revealing its “distinctive swirling bands of orange, brown and white.”
Rather appropriately for an American space endeavor, the fate of the entire mission hinges on do or die ‘Independence Day’ fireworks.
On the evening of July 4, Juno must fire its main engine for 35 minutes.
The Joy of JOI – or Jupiter Orbit Insertion – will place NASA’s robotic explorer into a polar orbit around the gas giant.
The approach over the north pole is unlike earlier probes that approached from much lower latitudes nearer the equatorial zone, and thus provide a perspective unlike any other.
After a five-year and 2.8 Billion kilometer (1.7 Billion mile) outbound trek to the Jovian system and the largest planet in our solar system and an intervening Earth flyby speed boost, the moment of truth for Juno is now inexorably at hand.
And preparations are in full swing by the science and engineering team to ensure a spectacular Fourth of July fireworks display.
The team has been in contact with Juno 24/7 since June 11 and already uplinked the rocket firing parameters.
Signals traveling at the speed of light take 10 minutes to reach Earth.
The protective cover that shields Juno’s main engine from micrometeorites and interstellar dust was opened on June 20.
“And the software program that will command the spacecraft through the all-important rocket burn was uplinked,” says NASA.
The pressurization of the propulsion system is set for June 28.
“We have over five years of spaceflight experience and only 10 days to Jupiter orbit insertion,” said Rick Nybakken, Juno project manager from NASA’s Jet Propulsion Laboratory in Pasadena, California, said in a statement.
“It is a great feeling to put all the interplanetary space in the rearview mirror and have the biggest planet in the solar system in our windshield.”
On the night of orbital insertion, Juno will fly within 2,900 miles (4,667 kilometers) of the Jovian cloud tops.
All instruments except those critical for the JOI insertion burn on July 4, will be tuned off on June 29. That includes shutting down Junocam.
“If it doesn’t help us get into orbit, it is shut down,” said Scott Bolton, Juno’s principal investigator from the Southwest Research Institute in San Antonio.
“That is how critical this rocket burn is. And while we will not be getting images as we make our final approach to the planet, we have some interesting pictures of what Jupiter and its moons look like from five-plus million miles away.”
During a 20 month long science mission – entailing 37 orbits lasting 11 days each – the probe will plunge to within about 3000 miles of the turbulent cloud tops and collect unprecedented new data that will unveil the hidden inner secrets of Jupiter’s origin and evolution.
“Jupiter is the Rosetta Stone of our solar system,” says Bolton. “It is by far the oldest planet, contains more material than all the other planets, asteroids and comets combined and carries deep inside it the story of not only the solar system but of us. Juno is going there as our emissary — to interpret what Jupiter has to say.”
During the orbits, Juno will probe beneath the obscuring cloud cover of Jupiter and study its auroras to learn more about the planet’s origins, structure, atmosphere and magnetosphere.
Junocam has already taken some striking images during the Earth flyby gravity assist speed boost on Oct. 9, 2013.
For example the dazzling portrait of our Home Planet high over the South American coastline and the Atlantic Ocean.
For a hint of what’s to come, see our colorized Junocam mosaic of land, sea and swirling clouds, created by Ken Kremer and Marco Di Lorenzo.
As Juno sped over Argentina, South America and the South Atlantic Ocean it came within 347 miles (560 kilometers) of Earth’s surface.
During the flyby, the science team observed Earth using most of Juno’s nine science instruments since the slingshot also serves as an important dress rehearsal and key test of the spacecraft’s instruments, systems and flight operations teams.
Continuing with our “Definitive Guide to Terraforming“, Universe Today is happy to present to our guide to terraforming Jupiter’s Moons. Much like terraforming the inner Solar System, it might be feasible someday. But should we?
Fans of Arthur C. Clarke may recall how in his novel, 2010: Odyssey Two (or the movie adaptation called 2010: The Year We Make Contact), an alien species turned Jupiter into a new star. In so doing, Jupiter’s moon Europa was permanently terraformed, as its icy surface melted, an atmosphere formed, and all the life living in the moon’s oceans began to emerge and thrive on the surface.
As we explained in a previous video (“Could Jupiter Become a Star“) turning Jupiter into a star is not exactly doable (not yet, anyway). However, there are several proposals on how we could go about transforming some of Jupiter’s moons in order to make them habitable by human beings. In short, it is possible that humans could terraform one of more of the Jovians to make it suitable for full-scale human settlement someday.
Watching the inky-black shadow of a Jovian moon slide across the cloud-tops of Jupiter is an unforgettable sight. Two is always better than one, and as the largest planet in our solar system heads towards opposition on March 8th, so begins the first of two seasons of double shadow transits for 2016. Continue reading “Double Shadow Transit Season for the Jovian Moons Begins”