Wake Up Rosetta!


Artists rendition of the ESA Rosetta mission, which is going to do more awesome things than I can possible describe in a single blog post! (But read on anyway!) [Image credit: ESA, Copyright: Astrium/E.Viktor]
It was late 2003, shortly after starting my job at NRL, when I was first offered the opportunity to do work involving comets. Until then, my knowledge of them was rudimentary to say the least, with just a very basic undergraduate understanding at best. Thus it was a steep learning curve when the Sungrazing Comets Project was thrust in to my hands. Unbeknownst to me, at the same time I was learning the fundamentals of comets and sungrazers, the European Space Agency (ESA) were putting the finishing touches to its Rosetta spacecraft - an ambitious and quite frankly extraordinary comet encounter mission to study comet 67-P/Churyumov-Gerasimenko. [psst: you can just call it "67P"... we do!]

Rosetta launched in early 2004, and that event I do vaguely remember, but with a ten-year cruise phase ahead of it before reaching 67P, I must confess I didn't really take that much notice. I do, however, recall peripherally thinking to myself, "hmm, I wonder if I'll still be doing anything with comets when it finally gets there in 2014?".

Oh, how little did I realize!

Anyway, it's Rosetta I want to talk about, not anecdotes. But first I want to take a step back a moment and mention why we care about comets, as that's important to where Rosetta fits in. There are many reasons for our interest in comets but, fundamentally, comets hold vital clues to how we actually came to exist. Our solar system began as a big rotating, swirling disk of dust that gradually began to clump together. We know the end results - we live on one of them - but clearly there's a lot of ground to cover if we're to go from "primordial swirly dust disk" to "sipping coffee while blogging".

We have some of the puzzle pieces in this timeline - certainly enough to be sure of the big picture - but there still remain some really important gaps that we want to fill that will help us understand how we actually came to exist. One of those gaps is understanding how that early stuff stuck together.
In the context of solar system formation we know how to make tiny dust grains stick together and form little chunks, and we know how to take big comet-sized chunks and stick them together to form planets. But what we don't yet understand is how we can collide the little chunks together and have them form comets, for example, as opposed to just blasting each other back in to dust. So, as my colleague Casey Lisse so beautifully likes to state, "Before you can build a planet, you first have to learn how to build a comet." We do not know how to build a comet!

And this is one of the crucial ways that Rosetta is going to help. The spacecraft is fully-loaded with a mind-boggling array of amazing science instruments that will study the chemical and physical properties of the comet, the dust and gases released from it, and even its interaction with the solar wind. But for me, the most exciting aspect of Rosetta is not just that it's looking at 67P's surface and dusty/gassy coma, but that it's actually going to look INSIDE the comet itself! How? Read on!

As the Rosetta spacecraft orbits 67P, it will use remote sensing instruments to send infrared and radar waves into the nucleus itself and return unprecedented information about the structure and make-up of the comet. This in itself is ridiculously awesome, but it gets better...

Rosetta will reach 67P in May of this year and enter into orbit around the comet with a planned mission lifetime lasting until December 2015. But the real fun comes in November 2014 when Rosetta will unleash a robotic surprise upon the comet! Known as the "Philae lander", or just "Philae", a 100Kg (~220lbs) remote laboratory will be released from Rosetta at around 1-kilometer (0.6miles) from the comet's surface, glide down at walking pace, harpoon the comet (!!) and then settle on the surface for (hopefully) weeks or months of detailed analysis.

This will be the first ever so-called soft landing on a comet. It's ambitious to say the least, and will certainly be both thrilling and terrifying for the Rosetta team, but I have no doubt that they can pull off this extraordinary feat! And I'm going to repeat what I just said a second ago because it's the kind of thing you don't tire of typing: ESA are going to literally HARPOON A COMET. If that doesn't give you at least a little thrill then you need to not be reading science blogs!

There are a handful of critical milestones in this mission, several of which have already passed in its ten-year cruise thus far, and a couple more still to go. But one of the most important is about to happen in just a few days from now, on January 20, 2014, when the mission controllers will send a signal to the spacecraft telling it to awaken from a years-long slumber in outer space!

It perhaps doesn't sound like much but it's actually a really big deal. The spacecraft and all of its instruments have essentially been on standby in the cold vacuum of space for several years, and on Monday it's all getting turned on in what ESA are quite rightly touting as "The Most Important Alarm Clock in the Solar System"! My understanding is that there will be a delay of a few hours between the wake-up command and the sleepy yawn filled "yeah, yeah, I'm awake..." response from the spacecraft. That'll be a pretty nervy time, but rather exciting too!


To promote the awakening of Rosetta after its ten-year voyage, ESA are promoting the #WakeUpRosetta campaign in which you could actually win a trip to the ESA MOC later this year! [Image credit: ESA]
To recognize the event, ESA have been promoting their #WakeUpRosetta campaign, and are encouraging people to make and submit their own "Wake Up Rosetta" videos. It's a really cool idea so I encourage everyone to join in. And then of course on Monday, you should stay close to your computer as the drama begins to unfold! The first command will be sent at around 1000GMT (0500EST) and the first chance of a signal back is around 1730GMT (1230EST).

Social media will be all over this, but the best Twitter accounts to follow will be the Rosetta mission itself, ESA Science, and the main ESA account. I'm sure NASA will be on it too, as there is a NASA-backed contingent involved in the Rosetta mission (but it's mostly ESA's show). And of course I'll probably have a thing or two to say on my feed but I'm sure you already follow me (right?!).

As someone who has developed something of a fondness for comets - despite the heartbreak they can sometimes bring - I really am quite ridiculously excited for this mission, and you should be too, for all the reasons I just outlined! It also launched at basically the same time as my comet career did, so I feel more than the usual kinship with this one. With the Rosetta mission, and the "Mars-grazing" comet C/2013 A1 (Siding-Spring), I have a feeling this is going to be another very busy, and very awesome, year!

Footnote: CIOC has gone quiet, hasn't it? Sorry about that! We're busy playing with our data and recovering from the excitement of last year. I want to get back into blogging more regularly but can't decide if this website is the best venue. I'm still thinking on that one, and am weighing my options for a more long-term blogging site.

Keep up-to-date on the latest ISON and sungrazing comet news via my @SungrazerComets Twitter feed. All opinions stated on there, and in these blog posts, are my own, and not necessarily those of NASA or the Naval Research Lab.