Emily Lakdawalla • Mar 06, 2013
Meteor showers on Titan: an example of why Twitter is awesome for scientists and the public
I use a variety of social networking tools to perform my job, but there's one that's more important and valuable to me than all the rest combined: Twitter. When I first started using Twitter I saw it only as a means to put information out, kind of like my blog only very much shorter. But over time I've come to rely upon it as my single source of news, whether it be space news or Earth news. Through my carefully cultivated and pruned list of people and organizations that I follow, Twitter is where I hear about press releases, new images from Mars, space news like the Russian meteor, world news like earthquakes and the deaths of political leaders, and local news like wildfires.
And Twitter is, more and more, the place where I interact with readers, fellow journalists, and scientists. Through Twitter I watch and, often, participate in ongoing discussions about journalism, space policy, and science. When I have a question, I ask it on Twitter and I get answers within minutes (sometimes, seconds). When I attend a conference, I can discuss the news and science with my peers through Twitter. Since the discussion is public, anyone can jump in to the conversation, and if their contribution is valuable, it will be amplified through retweets. Sometimes the discussion can get snarky but several studies have shown that on Twitter, a positive attitude has much more traction than a negative one, and that's definitely true on my feed; I routinely trim the list of people that I follow to remove people who get me down.
Yesterday afternoon there was a discussion on Twitter that exemplifies its value and fun, and I thought that I'd reproduce it here for the benefit of readers who have yet to be convinced that Twitter is anything but people posting photos of their dinners. One important Twitter convention to be aware of here is that when you begin a tweet with the "@" symbol and the Twitter username of another person, that's called a "mention" and it's a way of directing your statement or question at a specific person. But it's a conversation that's taking place out in public, which means that other people can jump in and join the conversation, as several do here.
It all began with me posting a link to my blog entry about a potential meteor shower on Mars. A reader (who goes by @BadPhysics on Twitter; I don't know their actual identity) had a question, and two scientists (asteroid astronomer Andy Rivkin and planetary rings guy Luke Dones) stepped in with answers to the question. Which was cool and very helpful of them, but the best was yet to come.
Will comet Siding Spring make a meteor shower on Mars? bit.ly/WtpDup
— Emily Lakdawalla (@elakdawalla) March 5, 2013
@elakdawalla Followup q: How visible would these be, given the thin atmosphere on Mars? What relative velocity required to reach white-hot?
— The Snark Side (@BadPhysics) March 5, 2013
@elakdawalla Meteor = "the visible streak of light." If they didn't burn up would Mars get "meteoroid shower"? Or might burn ~invisibly.
— The Snark Side (@BadPhysics) March 5, 2013
@badphysics @elakdawalla Meteor trains occur at >80 km height (amsmeteors.org/fireballs/faqf/) ~0.1-1 mb. Similar to pressure above Olympus Mons?
— Andy Rivkin (@asrivkin) March 5, 2013
@badphysics @elakdawalla End member case:science.nasa.gov/science-news/s…
— Andy Rivkin (@asrivkin) March 5, 2013
@asrivkin @elakdawalla Sweet. I wonder if they'd be more dramatic and prolonged due to gentler atmospheric gradient? #MarsMeMaybe
— The Snark Side (@BadPhysics) March 5, 2013
@badphysics @elakdawalla Also relevant:adsabs.harvard.edu/abs/2005Natur.…
— Andy Rivkin (@asrivkin) March 5, 2013
@badphysics @elakdawalla Earth meteors ablate at altitudes where atmos pressure is << Mars surface pressure, so Martian meteors visible.
— Luke Dones (@lukedones) March 5, 2013
@badphysics @elakdawalla e.g. this paper by Tolis Christou et al.: adsabs.harvard.edu/abs/2012P%26SS…
— Luke Dones (@lukedones) March 5, 2013
One thing that's happening here is that although the statements of each person are individually quite brief, there is a TON of substance in this conversation in the form of four links to authoritative articles: one an online FAQ about fireballs, one a transcript of a NASA podcast on lunar impact flashes, and two peer-reviewed papers about meteor flashes in the Martian atmosphere: one on a flash observed by Spirit and the other on a proposed wide-angle meteor-flash-hunting camera for a Martian orbiter. I had seen the first two links before but had been unaware of the two papers, which were fascinating.
A little later, a third scientist, Titan-atmosphere-making Sarah Horst, said this:
@asrivkin @badphysics @elakdawalla @lukedones I just had a sad when I realized you probably can't see meteor showers on Titan :(
— Sarah Horst (@PlanetDr) March 5, 2013
(Note: Sarah's unusual "I had a sad" syntax here is LOLspeak, an Internet lingo. As with other slang, linguistics researchers have described LOLspeak as "a form of language play that serves in-group cohesion: if you’re in on the joke, you’re part of the community.")
Sarah's comment inspired a lot of responses.
@planetdr @badphysics @elakdawalla @lukedones Probably could do the radio meteor thing with the right equipment, though.
— Andy Rivkin (@asrivkin) March 5, 2013
@planetdr @asrivkin @elakdawalla @lukedones Do a science: Factor in haze/ambient light/darkness adaption. Make graph size/velocity. Plot vis
— The Snark Side (@BadPhysics) March 5, 2013
@planetdr Not from the surface, but just another reason we need to watch Titan at all times with ALL the telescopes.
— Luke Dones (@lukedones) March 5, 2013
@planetdr @asrivkin @elakdawalla @lukedones If it is big enough you will probably see something. Russian meteor was brighter sun, even here.
— The Snark Side (@BadPhysics) March 5, 2013
@badphysics The Russian meteor was brighter than the Sun in California? Why weren't we told about this earlier?
— Luke Dones (@lukedones) March 5, 2013
@badphysics @asrivkin @elakdawalla @lukedones of course. but earth sea level pressure ~10 km alt in Titan's atmosphere. +lots more absorbers
— Sarah Horst (@PlanetDr) March 5, 2013
@lukedones When talking to @planetdr, all discussion is relative to Titan. Her head is in the clouds. Of tholins.
— The Snark Side (@BadPhysics) March 5, 2013
@badphysics @asrivkin @elakdawalla @lukedones damnit now I want to write a paper. where's Ralph?
— Sarah Horst (@PlanetDr) March 5, 2013
@planetdr In a hypothetical world in which Titan had native inhabitants, I bet they'd have infrared eyes, and could see them.
— Rachel Klippenstein (@tunglere) March 5, 2013
@planetdr Since it's probably not accidental that our eyes see wavelengths that pass through our atmosphere well.
— Rachel Klippenstein (@tunglere) March 5, 2013
@tunglere I have never thought about this...what wavelengths they would see...
— Sarah Horst (@PlanetDr) March 5, 2013
@planetdr @tunglere The key now is figuring out which Futurama episode covered this.
— Luke Dones (@lukedones) March 5, 2013
@tunglere don't know what they would see. we r combo of photons sun emits + photons that don't get absorbed. On titan just not many photons
— Sarah Horst (@PlanetDr) March 5, 2013
.@tunglere, in true @tunglere fashion, now has me thinking about what wavelengths Titanian eyes would see...
— Sarah Horst (@PlanetDr) March 5, 2013
The conversation turned from science to wonder with the arrival of a new conversation participant, Rachel Klippenstein (@tunglere) -- someone who is not a space scientist, but rather a grad student in linguistics. Yet, through the medium of Twitter, here we all are, inspiring and learning from each other. Sarah may even have hit upon the idea for a new scientific paper (her comment "Where's Ralph?" refers to Titan scientist Ralph Lorenz, who has a history of thinking about and publishing papers on wonderful, out-there ideas). Like 95% of anybody's ideas for papers, this one likely won't actually go anywhere, but random "I wonder...." thoughts and conversations do wind up inspiring a large amount of scientific research.
Anyway, scientific discussion continued:
@planetdr What happens when water-ice comet hits Titan, and the water thermally disassociates? O go back to the H, or to CH4? #BurningQ
— The Snark Side (@BadPhysics) March 5, 2013
@badphysics it will stay as water (b/c there is lots of H/H2 running around in Titan's atmosphere) but H2O eventually mostly becomes CO2
— Sarah Horst (@PlanetDr) March 5, 2013
@badphysics (finally a question I know the answer to)
— Sarah Horst (@PlanetDr) March 5, 2013
@planetdr Guessing most effective wavelengths wd be those Cassini uses for pics of Titan's surface - they can go through haze some at least.
— Rachel Klippenstein (@tunglere) March 5, 2013
@planetdr @tunglere I guess you would be the expert. I presume you have an absorption or transmission curve handy? I'm very curious also. :)
— Bud Christenson (@budc1958) March 5, 2013
@planetdr @tunglere I realize there's a lot of scattering at most wavelengths, but scattered light is useful - just not for seeing stars.
— Bud Christenson (@budc1958) March 5, 2013
@tunglere most of the wavelength filters are actually regions where methane doesn't absorb. the haze isn't as much of a problem
— Sarah Horst (@PlanetDr) March 5, 2013
@planetdr Ah, OK.
— Rachel Klippenstein (@tunglere) March 5, 2013
@budc1958 @tunglere our model does those calculations, but I don't actually have a spectrum of the light that makes it to the surface handy
— Sarah Horst (@PlanetDr) March 5, 2013
@planetdr @badphysics @asrivkin @lukedones Enjoying the meteors-on-Titan conversation. Carry on.
— Emily Lakdawalla (@elakdawalla) March 6, 2013
@elakdawalla @badphysics @asrivkin @lukedones OTOH, might be able to see more b/c always pretty dark on Titan. so....daytime meteor showers?
— Sarah Horst (@PlanetDr) March 6, 2013
@elakdawalla @badphysics @asrivkin @lukedones Titan at brightest ~ dusk on Earth...hrm...
— Sarah Horst (@PlanetDr) March 6, 2013
@planetdr @tunglere Since the atmosphere is 90% Nitrogen that would bracket it somewhat, similar to Earth but a lot of blue also blocked.
— Bud Christenson (@budc1958) March 6, 2013
@planetdr @elakdawalla @badphysics @lukedones I'm not thinking so. I'd think they don't penetrate nearly far enough to get below the clouds.
— Andy Rivkin (@asrivkin) March 6, 2013
@planetdr @elakdawalla @badphysics @lukedones Also, I _think_ impact speeds will be slower? Big atmosphere, low gravity-hit terminal v soon?
— Andy Rivkin (@asrivkin) March 6, 2013
@planetdr @elakdawalla @badphysics @lukedones So a Titan atmosphere skimmer might grab a lot more IDPs than here? Plus in-system dust.
— Andy Rivkin (@asrivkin) March 6, 2013
@asrivkin @elakdawalla @badphysics @lukedones the methane eats most of the photons. haze causes other issues...so if bright enough might see
— Sarah Horst (@PlanetDr) March 6, 2013
@asrivkin @elakdawalla @badphysics @lukedones micrometeroid peak ablation ~750 km alt. never seen calculation for larger pieces...
— Sarah Horst (@PlanetDr) March 6, 2013
@planetdr @asrivkin @elakdawalla @lukedones Titan 16 days to go 7.7Gm = 5.6km/s OV? Added/subtracted from Saturn's 9.69 = range 4~15km/s?
— The Snark Side (@BadPhysics) March 6, 2013
@asrivkin @elakdawalla @badphysics @lukedones Titan meteors ~ 9.5 km/s, Earth ~16.5 km/s (English 1996)
— Sarah Horst (@PlanetDr) March 6, 2013
@planetdr @tunglere Didn't the Huygens probe sample the light that reaches the surface?
— Louis Brown (@LouisBrown16) March 6, 2013
@louisbrown16 @tunglere absolutely Descent Imager/Spectral Radiometer (DISR) designed to characterize the crap out of light on Titan
— Sarah Horst (@PlanetDr) March 6, 2013
.@planetdr @elakdawalla @badphysics @asrivkin @lukedones So, theoretical titan eyes may not really be in the vislight spectrum?
— Louis Brown (@LouisBrown16) March 6, 2013
@budc1958 @tunglere @louisbrown16 here you go. (from Tomasko 2008) twitter.com/PlanetDr/statu…
— Sarah Horst (@PlanetDr) March 6, 2013
@planetdr @asrivkin @elakdawalla @lukedones Homework Assignment for PlanetDr: Fill this out with numbers plz. ????? twitter.com/BadPhysics/sta…
— The Snark Side (@BadPhysics) March 6, 2013
@planetdr @tunglere @louisbrown16 Fascinating! There could be several answers, but the highest xmsn band does bracket 938 nm!
— Bud Christenson (@budc1958) March 6, 2013
@planetdr @tunglere @louisbrown16 In said hypothetical cryobiosphere you could argue that band would be useful for predator/prey detection.
— Bud Christenson (@budc1958) March 6, 2013
@planetdr @tunglere @louisbrown16 Logic would dictate that any Titanians would be deep under the ice, so fun to ruminate but moot. :\
— Bud Christenson (@budc1958) March 6, 2013
The conversation continued beyond this, late into the evening, bringing in more participants, further discussion of whether there might be meteors visible in other places (like Triton), and mentions of martinis and mojitos. It seemed pretty clear that human eyes wouldn't likely see many meteors on Titan from Titan's surface, but the discussion of what native Titan life could see was, of course, unresolved. Discussions wind up feeling like the discussions we have over drinks after scientific conferences, except that non-space-scientists can join in, too, bringing in their richness of knowledge and experience; and there are many, many more people eavesdropping, watching and learning about things that it hadn't occured to them before to be curious about. These kinds of conversations happen all the time on Twitter, and I certainly feel richer for having the chance to observe them.
So, if you don't already, follow me on Twitter; I think you'll be glad you did! For ideas on whom to follow you can look at my list, but one of the great things about Twitter is that you are responsible for curating your own list of follows, things that are meaningful and useful specifically to you. If you follow too many people and your stream gets overwhelming, just prune it. I routinely unfollow people that I like and who tweet interesting things in an effort to keep my stream volume manageable; it's of no use to you if it's too overwhelming to read. Unlike on Facebook, where "unfriending" carries so much emotional baggage, unfollowing someone on Twitter is not considered (by most people) an insult. I know that people unfollow me episodically because when I attend conferences or press briefings I tweet at a very high volume that some find overwhelming. If you unfollow me for this reason, I don't take it personally; I hope you will follow The Planetary Society's official Twitter stream, @exploreplanets, which has much lower volume.