So there are just about 5-days to go until comet Siding Spring buzzes past Mars, and everyone is getting into gear to obtain some great new science! I want to keep this post brief, but there are a couple of news items I want to share.
This evening - Tuesday October 14th, 2014 - myself (Karl Battams), Matthew Knight and Jared Espley from the NASA MAVEN team will be doing an "Ask Me Anything" on Reddit. The link for the chat isn't live yet, but if you keep an eye on that sub-reddit, you should see our chat go live around 8:30pm Eastern Time.
I'll add the link to this blog post once I have it. We'll be taking, and attempting to answer, any questions you might have about Comet Siding Spring, its close approach to Mars, the CIOC, and comets in general. Here is the link to our Reddit Ask Me Anything!
A couple of days ago, there was a NASA press conference to discuss the Siding Spring encounter, including CIOC Chair Casey Lisse, our amateur astronomy liaison and coordinator Padma Yanamandra-Fisher, and NASA HQ's Kelly Fast and Jim Green. I've embedded the press conference replay below so you can watch at your leisure. Lots of good info in there!
We've been fairly heavy on talking up the NASA spacecraft involvement in Siding Spring observations, but the European Space Agency (ESA) are as excited about this opportunity as NASA are. They have their Mars Express satellite orbiting Mars (returning jaw-dropping images!) and, upon hearing of the Siding Spring passage, they ESA folks went through many of the same discussions that the NASA teams did. They assessed the risks to their spacecraft, keeping open the option of turning their main antenna towards the direction of potential comet dust and powering off all non-essential systems, and looked at what potential science return they could get from the encounter. They had to weight the pros and cons, risks and benefits, and figure out how to balance all of this. (It's complicated - spacecraft aren't simply remote telescopes that you can point around on a whim.) The good news is that they've made a decision to go pretty much all out on the science front, now we're confident that dust poses no risk to Martian spacecraft. You can read all about their plans in their recent blog post.
I've had a couple of questions on my Twitter account asking if there will be any special events planned for the day of close encounter. I don't know for certain, but my understanding is that there will not be anything planned for that day. This isn't because we don't care and/or it's not exciting - trust me, we care, and it's thrilling to us! The main issue, I think, is that there's simply not much that will be happening in realtime. With Comet ISON last year, we were all glued to near realtime images of the comet as it plunged into the solar atmosphere. The Mars spacecraft don't work like that; they don't return images in realtime the way the solar spacecraft do. Instead, most of their data is stored on-board, and later downlinked when they have a contact with the Deep Space Network (DSN).
I have no idea exactly when those teams will announce preliminary results - it could be hours or days. I have pretty much zero familiarity with the Mars spacecraft operating procedures and processing pipelines so I won't even pretend to guess. I am sure they'll share results as soon as they can, but it won't be in real-time, and hence there's not really much we can do "live" on close approach day. Of course, I will be staying close to my @SungrazerComets Twitter feed, so I'll post any updates that I get. If I do hear of any "encounter day" plans, then of course I'll share them on here and Twitter.