Good Luck to Phoenix

Just wanted to wish the Phoenix mission good luck and I hope their landing on the Martian northern plains goes off without a hitch.

Update: Phoenix landed! WOOT!

Io Volcanic Observer at LPLC

Yesterday was the second and final day of the Lunar and Planetary Laboratory Conference in Tucson, Arizona. This is a small conference where researchers at the University of Arizona's Lunar and Planetary Laboratory can share their current work with their colleagues here. Many of the talk in the morning where dedicated to dynamics and space physics. I am amazed I stayed awake...

The afternoon sessions included Titan and other satellites in the Solar System. I gave a talk on Cassini images of Titan, particularly those of Titan's polar regions. Alfred McEwen, my advisor, gave a talk on the Io Volcanic Observer (IVO, pronounced eye-voh), a mission concept in the Discovery & Scout Mission Capability Expansion (DSCME) program. I have reported on this concept study previously and on the abstract McEwen submitted to the conference.

The talk provided a few new details on this mission concept. The IVO team is aiming for a 2013 launch on an Atlas V with a back-up launch date in 2014. The spacecraft would be launched into a Venus-Earth gravity assist trajectory with an arrival at Jupiter in the 2019 timeframe. Once at Jupiter, IVO would flyby Io shortly before Jupiter orbit insertion, which would lower JOI delta-V and provide an insurance flyby in case any issues occur during the JOI burn. Once at Jupiter, IVO would be injected into a 200-day orbit around Jupiter with a 45 degree inclination.

Over the course of the 1-2 year mission, IVO would use 5-10 Io flybys to bring its orbital period down to 30 days. Each flyby would have a close-approach distance between 500 and 1000 km with 100 km flybys possible later in the mission. The high-inclination orbit would provide much needed polar coverage, which would be complementary to observations acquired by Galileo and the Europa orbiter mission. Flybys would occur at similar solar longitudes on Io to reduce the variables when comparing images between flybys.

The base payload for IVO includes a narrow-angle camera, a Thermal Imager, a Neutral Mass Spectrometer, and a Radiation detector for a total payload weight of 34 kg (44 kg with 30% margin). The nominal narrow angle camera planned would weigh 15 kg and would have a resolution of 10 microradians per pixel (the same as Galileo SSI). The goal for this camera is to observe Io's ever-changing surface by observing the same volcanic features during each flyby. The camera would also be used to measure Io's limb topography, which would help constrain Io's tidal bulge and thus provide constraints on Io's current tidal heating. The camera will make use of active pixel sensors, which have increased radiation hardness compared to traditional CCDs. These sensors will also allow the IVO team to acquire simultaneous multi-spectral imaging. This would make acquiring color mosaics a much simpler task as well as help support lava temperature measurements, since lava fountains can change on the order of seconds.

The Thermal Imager would be similar to the THEMIS instrument on the Mars Odyssey spacecraft. The IVO team is looking for an instrument that would acquire near- to mid-IR imaging at 3, 8, and 20 microns, to measure Io's heat flow. Assuming something akin to THEMIS is used (which is possible considering that the PI for THEMIS, Phil Christensen, is on the IVO team), the Thermal Imager would have a 4.6 deg. FOV with 250 microradians/pixel resolution (effectively 1 km/pixel per 4000 km).

Unfortunately, Alfred was nearing his alloted time by the time he finished discussing the Thermal Imager so he didn't spend time covering NMS, UVS, and the Radiation Detector. He pointed out that the "Powerpoint" mission might have a chance in Hell of flying, considering that Io is a world of fire and brimstone, there is a team member named Dante, and that Alfred will be 66 years old when IVO arrives at Jupiter (assuming that IVO flies on the back-up 2014 VEEGA trajectory).

Io Wallpaper

Wanderspace has posted two new Io wallpapers for your computer's desktop. These graphics are based on mosaics I put together a few months ago. One graphic uses a mosaic from I27 and covers Sobo Fluctus, a volcano between Chaac and Camaxtli on Io's anti-Jovian hemisphere (seen on the right side of the graphic at left). The other uses a mosaic of Tvashtar Patera from I32 that was then colorized by UMSF reader Ricardo Nunes.

Link: Volcanic Io Wallpapers [wanderingspace.net]

Awesome Images of Io transiting Jupiter

I haven't posted any links to images acquired by amateur astronomers lately, but trust me, Io is still there. Paul Haese acquired a couple of very nice views of Io transiting in front of Jupiter on May 10. The detail is good enough to easily make out the difference in brightness between the equatorial and polar regions. Christopher Go and Tomio Akutsu acquired several images of an Io transit on May 1.

Geologic Mapping of the Zal region of Io

There is a new article in press in the journal Icarus titled, "Geologic Mapping of the Zal region of Io," by Melissa Bunte, David Williams, and Ron Greeley. A summary of their results was presented in March at the Lunar and Planetary Sciences Conference and was reported on here. Now the full paper is available on the Icarus website (subscription required to view paper). This paper is based on imagery acquired during the I25 and I27 Galileo encounters with Io.

Like many of the regions mapped by the ASU previously, such as near Camaxtli Patera, Tohil Mons, Amirani, and Thor, the authors mapped 5 basic units in the region: mountains/plateaus, smooth/layered plains, patera floor material, flow material, and diffuse materials. The flow features in this area appear to be generated from a small patera lying near the western margin of South Zal Montes (they propose the name "Rustam Patera" for this volcano) or from a fissure that runs north from "Rustam" along the western margin of South Zal Montes and the eastern margin of North Zal Montes. The flows include bright flows (possibly of sulfurous composition) radiating out from "Rustam" and dark flows which flow east across part of Zal Patera from the northern part of the fissure. Additional flow features are also seen within Zal Patera, but these appear to be older in age based on their brighter appearance.

One interesting hypothesis made in this paper is that the various components of Zal Montes, which surround Zal Patera to the west, east, and south, were originally part of a single structure. This feature then broke-up due to strike-slip then extensional faulting, opening up Zal Patera. Similar plate tectonics-in-miniature is theorized for formation of Hi'iaka Patera. The paper goes on to describe the degradational processes that have occurred at the mountains in the region.

One feature I wished the paper expounded on further is a small volcano west of North Zal Montes, which they suggest the name "At'am Patera" for. What makes the volcano interesting is that it appears to be one of a very rare breed of explosive Ionian volcano. "At'am" erupted between late-June and mid-September 1997, producing a white, Sulfur dioxide-rich plume deposit and a dark-green pyroclastic deposit with a digitate margin. Some of both materials was deposited on North Zal Montes. The digitate appearance is due to the interaction between the pyroclastic flow and the arcuate margin of the western part of North Zal Montes. This morphology may provide clues on how these pyroclastic deposits are formed on Io. Oddly, for an Ionian eruption, no lava flows or thermal emission were observed at this volcano. Also, the central vent is among the smallest paterae found on Io. It is possible that the 1997 eruption could have been the result of an intrusive event, where magma ascends from a deeper chamber, but fails to reach the surface. However, volatiles and other materials, being more buoyant, do make it to the surface.

The paper does touch a bit on the plume seen at Zal last year by New Horizons. This plume is centered on Zal Patera (unlike the plume deposit seen by Galileo starting in Sept. 1997 which surrounds "At'am Patera"). Zal Patera is also the site of fresh surface changes, which include a new dark plume deposit and fresh dark lava flows.

Link: Geologic Mapping of the Zal region of Io [dx.doi.org] (subscription required to view paper)

More Details on Io Volcanic Observer

As mentioned last month, NASA has commissioned several concept studies for Discovery-class mission that make use of the new Advanced Stirling Radioisotope Generator (ASRG) power source, a more efficient RTG that makes use of plutonium for power. One of these concepts is the Io Volcanic Observer (IVO), a mission to study Io's volcanic activity.

The leader of the study, Alfred McEwen, submitted an abstract on the mission concept to the Lunar and Planetary Laboratory Conference (LPLC) to be held next week in Tucson. I will be there giving a talk on the state of Cassini Imaging, particularly imaging of Titan. The abstract makes public a few more details on the study. The IVO team envision a small spacecraft that orbits Jupiter in a highly inclined orbit, encountering Io at every periapse. The high-inclination orbit helps to reduce IVO's radiation exposure during periapse. Each orbit would last between 30 and 200 days, though shorter orbit would provide better distant monitoring.

Due to the low-cost of the mission, the payload has to be kept simplistic. The team has currently include a baseline payload of a narrow-angle camera (with some color imaging capability), a thermal imager (capable of mapping Io's thermal emission at 3, 8, and 15 microns, and at some silicate absorption bands), a Neutral Mass Spectrometer, and a Radiation detector. Other potential instruments include a Wide-angle camera, an ultra-stable oscillator (used for gravity measurements), a near-infrared spectrometer (I guess a toss-up between this and the thermal mapper), an ultraviolet spectrometer, and a magnetometer.

The team has also outlined the scientific goals for this mission which include understanding Io's volcanic processes, composition, heat flow, and environment.

Link: Mission Concept: Io Volcanic Observer (IVO) [www.lpl.arizona.edu]

Things I Missed Playing Grand Theft Auto

Okay, I have some time to post some items I missed last week because I was busy helping Niko Bellic get revenge in Liberty City:

• According to Io9.com, Europa is the awesomest moon in the Solar System. Of course that is wrong, it isn't. Not by a long shot. Io is just as colonize-able as Titan (pick your poison: radiation or carcinogenic sand dunes). Ganymede is more so than Europa (using amount of radiation as a metric). And why does Enceladus have one blip for "Potential to colonize" but Phobos and Deimos get four. Thanks to Juramike at UMSF.com for the heads up.
  
• Io has been hiding out from the astrophotographers over the last few weeks. Christopher Go captured a nice view of Jupiter with Io's shadow on May 1. "Asimov" posted some of his captures of Io and Jupiter from this morning on the South Celestial Pole forum.
• I still haven't read that Io footprint paper.

Grand Theft Auto: Io

As you can see, I still haven't gotten around to working on the post for the Io footprint paper. I had planned to get to it Monday, but unexpected work got in the way (new and interesting Titan images). The reason I had to get to it Monday was because starting Tuesday, I would have very little free time between working, eating, sleeping, and playing Grand Theft Auto IV, which hit stores the other day.

Grand Theft Auto IV is a video game for the Xbox 360 and Playstation 3 consoles. The game follows a Eastern European immigrant, Nico Bellic, in a fictionalized version of New York City as he tries to escape his past and build a new future with the help of his cousin, Roman. The game, like its predecessors, has garnered attention for its graphic depiction of violence, however, it has garnered praise from nearly every reviewer for its epic plot (leading some to call it the "Godfather" of video games) and great gameplay.

I bought the game during my local Gamestop's Midnight Madness Sale. Basically, the game was released on Tuesday, and to capitalize on the craving people have for playing this game, they open to store at midnight so people can be among the first to own a copy. The closest Gamestop to my apartment is only three blocks away in the best shopping center in Tucson (along with a Gamestop, it has a Best Buy, a Wal-Mart, a good shoe store, and a camping store).

So I walked down to the store at a little before 10pm on Monday night, expecting to find maybe five people waiting in line to buy the game. Instead, I found 20 people already there. Waiting in line for two hours wasn't too bad. The employees knew how to treat their queue, giving out free chips, candy, soda, and water, setting up a TV outside to play some episodes of The Simpsons, and holding a raffle for random GTA IV-related merchandise, like posters, lanyards, and, wait for it, an empty box. I didn't win anything in the raffle, but I was pretty satisfied sitting in line with my chips, water, and iPod. By the time midnight rolled around, there had to have been at least 100 people in line, if not more, since I couldn't see the end because it stretched around the corner of the complex. I should note, to my surprise, that I did spot one woman in line for this game who WASN'T there with her boyfriend/husband/girlfriend. Not sure what that says about the audience for the game or the kinds of people who are stupid enough to wait in line to buy a video game at midnight on a weeknight.

Finally, at 12:07am on Tuesday, I had my hands on the game I coveted for a few days now (okay, I preordered it several months ago...). I've played quite a lot of it over the last couple of days (almost 11 hours worth, so now you see why I have had no time to skim through a paper on aurorae). It is a very good game. Is it worth the perfect scores given to it by nearly every reviewer, I'm not sure about that. But it is definitely the best game I own and nearly the best I have ever played, but that's not to say that there aren't a few things that bother me about the game, or bugs in the game that I've noticed.

I will try to post on any news item I see on Io or post about some new astrophotography, but I would not expect any major posts (beyond this one) from me this week.

The Variation of Io's Auroral Footprint Brightness with the Location of Io in the Plasma Torus

There is a new article in press in the journal Icarus titled, "The Variation of Io's Auroral Footprint Brightness with the Location of Io in the Plasma Torus," by Andrew W. Serio and John T. Clarke. I don't have access to the paper from home, but I'll be sure to download it tomorrow and post about it here.

Link: The Variation of Io's Auroral Footprint Brightness with the Location of Io in the Plasma Torus [dx.doi.org]

Another Video from Youtube

I missed this last night while looking for Io videos on Youtube. It is made by the same folks who couldn't get a decent CGI Io going, but this is a lot more informational with interviews with various scientists who participated in the Voyager and Galileo missions. Not bad, a few minor errors that only people like myself would notice (nothing groan worthy that I noticed).

EJSM Workshop in Rome

The Europa/Jupiter System Mission JSDT hosted two meetings this week in Rome, Italy to further develop the payload for ESA's proposed Jupiter Planetary Orbiter and the scientific objectives and Europa and Jupiter, as well as to solicit input from the community on the kinds of science that might be done at the Jupiter system with these 2-4 spacecraft.

While I don't expect anything to be published online from the internal JSDT meeting, we might see stuff from the open community meeting that took place on Monday and Tuesday. The agenda for this meeting is online. Looks like some interesting topics were discussed with John Spencer presenting on Io science. The first day looks like mostly a series of presentations on science objectives for the various mission components as it stands now for EJSM. The second day is a mix of the team presenting what they have so far on the payload development, followed by suggestions for payload elements from the community.

I'll report here if I hear any news from this meeting.

Link: Europa-Jupiter International Science Workshop [www.ifsi-roma.inaf.it]

Io on Youtube

Continuing my series on Io resources online, today we look at Io on the world's largest video sharing website, Youtube. To be honest, I am not a big Youtube user, visiting the site maybe a few times a month. Most of the videos on the site just aren't all that interesting to me, or are clearly aimed at an audience that I am not part of. But still there are a few interesting Io-related videos on Youtube:

• The one above is perhaps my favorite, the history of Io in song form, complete with accordion and mandolin.
• A video from the Europan propaganda machine (with Bill McKinnon)
• Video Podcast from the New Horizons flyby showing the reaction of Hal Weaver, Andy Cheng, and John Spencer to the first images down of Io - Part 1 and Part 2.
• There is a nice clip from a BBC "documentary" called Voyage to the Planets with a segment on Io. Worst. Fake. Io. Ever! First, what dumb idiot would land on a lava flow? The fact that you landed near a fracking skylight should have told you something, but no... Second, I may have missed that part of my Physics classes, but I seem to recall something about light (and that includes TV transmissions from the surface of Io) taking an hour or so to go from Io to Earth... Am I the only one who is hoping for either A) Radiation sickness striking "I don't need my anti-radiation pills" Zoe or B) that the ground opens up beneath "Hmm, this crusted over lava flow looks like a nice place to land" Zoe? Don't go toward the light!
• The theatrical trailer for Outland
• Message from Io - Another Io song
  

A little preview

Just a little preview of what I have been working on lately for the blog. This mosaic uses Voyager 1 images and shows the southern hemisphere of Io from just east of Masubi to just east of Pele. I want to change the stretch used to help bring out subtle features within this mosaic. The finished version will be about 4x the size of the mosaic linked to at left.

Globes of the Galilean Satellites

The OPAG site has a pamphlet on a series of globes that Sky&Telescope has been working on for a few years. Now that USGS has finished up their set of Galilean satellite basemaps, S&T may put these globes on sale soon, though they are still looking for input on what would be a good price point and are looking to gauge interest. The globes look very nice, and I would certainly pick up the Io globe, but according to the pamphlet, it looks like S&T wants to sell these as a set rather than individually. The globes would also be limited to 9 inches in diameter.

I would certainly pay 100 bucks for a 12 inch diameter Io globe. Not sure about this set.

Link: Globes of the Galilean Satellites [www.lpi.usra.edu]

Finding Raw Images of Io Online

Continuing my series of posts covering Io resources online, today we look at raw images of Io. The images you see online of Io are processed from raw images acquired by various NASA spacecraft, including the two Voyagers, Galileo, Cassini, and New Horizons. For the time being, I am excluding Pioneer 11 and Hubble from this discussion, but I may come back to those at a future date. All the images acquired by those five spacecraft of Io are available online for you to process into your own masterpieces. Today, I'd like to show you where and how to acquire these images.

Raw images from NASA spacecraft are available from the various nodes of the Planetary Data System or PDS. The PDS archives and facilitates the distribution of data from NASA's unmanned planetary spacecraft. With the exception of the New Horizons images, images are archived in IMG format. This format is not supported by most photo editing software, like Photoshop, but these images can be accessed using various freeware programs available online. One tool I recommend is IMG2PNG, created by Bjorn Jonsson. This converts IMG and FITS images into PNG files (even 16-bit files if the original images require it). IMG2PNG will even calibrate Cassini images. You can then mess around with those PNG files in Photoshop or GIMP.

Anyways, here is a rundown of sites where you can find raw Io images:

• The PDS Rings discipline has a search form for Voyager 1 and 2 images located on their website. From this form, you can search for Io images by spacecraft, camera, filter, and exposure time. The main annoyance is that the search only displays 10 records at a time if you choose to view preview gifs with each record, which really helps you find the image you are looking. You have to back out to the search page and put a number into the Skip field to go to a certain number record, if you display preview gifs. Also make sure you set the listing type to detailed, under Query Options on the search page if you intend to download the raw images. The images themselves can be downloaded by clicking on the links ending in IMQ for the image.
• The PDS Imaging Node hosts a search form for Galileo raw images. This form allows you to search for Io images by orbit as well as access NIMS cubes. If you want to download Io images, be sure to select GO-J/JSA-SSI-2-REDR-V1.0 as the dataset ID. The results pages are a little more intuitive than the Voyager page. Each images comes with its own separate page where you can download the image and look at various label information regarding that particular image. Just click on the "Download Full Resolution File" link to access the raw image.
• The PDS Imaging Node also hosts a search form for Cassini raw images. This form is a bit more complicated, not to mention the fact that the Cassini data set also includes a number of Io images where Io isn't the target, Jupiter is. I do not have much experience with using the Cassini PDS site though this search doesn't seem to be as intuitive as the Galileo form.
• The PDS Small Bodies Nodes hosts the New Horizons raw images. This page is does not have a search form, so you can either download the entire dataset using wget or download each volume as a giant tarball. Different pages online such as the official New Horizons Science Operations Center or my Io New Horizons page can give you an idea as to which images are Io images in the dataset.

In addition to these search pages, you also download the Galileo, Voyager, and Cassini datasets just as you would the New Horizons images, using wget.