Sen—In little more than a year's time in July 2016, NASA's Juno spacecraft will enter in to orbit around Jupiter. It might seem a long way off, but the mission's team is already preparing for the event. In particular the team is getting ready by enlisting amateur and professional astronomers in monitoring Jupiter from Earth before and after Juno's arrival for their JunoCam experiment.
Before I get to JunoCam, let's talk more about Juno and its mission. Launched in 2011, Juno is the second of NASA's medium-sized New Frontiers missions, (the first being the New Horizons probe, scheduled to rendezvous with Pluto in July, and the latest in this line of missions being OSIRIS-REx, a Near Earth Asteroid sample return mission set to launch next year). The spacecraft is expected to observe Jupiter for one year coming within 5,000 km of the top of the planet's atmosphere.
Unlike its predecessor Galileo, Juno is solar powered thanks to improved solar panel technology and construction. Juno will be the furthest operating solar-powered NASA spacecraft: Both Voyager probes, currently moving ever further into the outer Solar System, Saturn's Cassini probe and New Horizons on its way to the Kuiper belt are nuclear powered.
The aim of Juno is to better understand Jupiter's formation and structure as well as study the planet’s dynamic aurorae.
For the largest planet in our Solar System, there's a lot we don't know. Juno will probe deep into the interior of Jupiter’s atmosphere to measure its physical properties including composition, temperature, and velocities of cloud belts and storms. Juno will provide a window into the giant planet's interior structure by measuring Jupiter's gravitational field and magnetic field to the highest precision to date.
Like many of the robotic missions on-going in our Solar System, Juno is searching for water, but this time it's looking in Jupiter's atmosphere. In 1995, NASA's Galileo spacecraft dropped a probe that parachuted through Jupiter's atmosphere measuring composition, pressure, and wind speeds before it was crushed by the enormous gravitational forces deep in the planet's atmosphere. Surprisingly, the probe measured very little water in the atmosphere. The measurement was way lower than expected by formation models that assumed Jupiter would have incorporated icy planetesimals into its interior and atmosphere early on during its formation.
One possible explanation is that planetary scientists were just very unlucky. The probe took one line through Jupiter's atmosphere. There's a chance the craft's trajectory could have missed the water-rich regions and simply descended in a water-starved area at the edge of two weather bands in Jupiter's atmosphere. Juno should once and for all put to bed the mystery of the missing water in Jupiter's atmosphere. The probe will be able to measure water abundance as a function of latitude, longitude, and depth within the giant planet's atmosphere by looking for its signature in the microwave wavelength. If there’s water there, Juno should find it.
Another interesting aspect to Juno's payload is the JunoCam outreach experiment. Thanks to Juno's North to South orbit, JunoCam will have an unprecedented vantage point, providing the first up close color views of Jupiter's poles. Although the polar areas will be stunning, Juno's 11-day orbit will cover all latitudes on Jupiter, and where JunoCam points and what regions of Jupiter are imaged will be decided with input from the general public. In essence, JunoCam is the people's camera and will be a collaboration between planetary scientists, amateur astronomers, and the general public.
Deciding where on Jupiter JunoCam should image will require full globe images of Jupiter to obtain the current state and structure of the cloud belts and storms. JunoCam itself won’t be able to provide that. JunoCam needs your images of the planet. The JunoCam team is asking the amateur community to help provide the crucial context images it needs. It’s hard for planetary astronomers to get dedicated telescope time to continuously monitor Jupiter, but high-resolution full disk images of Jupiter can be readily obtained from relatively small ground-based telescopes and video imaging. Roughly one month before JunoCam will image, using the submitted ground-based observations, the JunoCam team will narrow down the possible areas of interest. From the list, the final target will decided by the general public voting via the JunoCam webpage.
If you're interested in taking part in the JunoCam ground-based observational effort, check out this information pamphlet the team has put together. It explains what the science team is looking for and the format they require.
As a test run for Juno's arrival, the JunoCam team is asking amateur astronomers to send a small number of Jupiter observations, starting on April 28 through May 26, 2015. The idea is to check out the system to transmit and process the ground-based observations and also give the observing community a chance to become familiar with the setup for submission. Then later on this year, the Juno submisison site will open again to officially start collecting any and all current observations of Jupiter that you're willing to obtain and contribute.
I am excited to see what this collaboration between planetary scientists, amateur astronomers, and the public will bring once Juno arrives at Jupiter.
A tip of the hat to Leigh Fletcher for bringing this to my attention on Twitter.