We're the Aussie scientists who recovered that older-than-earth meteorite (Desert Fireball Network) - Ask us anything!

We recently recovered our first meteorite using the new all digital network that we've developed fully in house. It's especially significant to us because confirms that the network and data reduction pipeline works end to end.

A few people had questions about how the whole thing works from spotting it on the cameras to finding the rock, so we're doing an AMA!

We dug it out of Kati-Thanda (Lake Eyre) South on New Year's Eve just as the rains were coming in that would have wiped away the evidence of where it landed (it would have probably been lost forever). You can read about the discovery here:

The Desert Fireball Network is a planetary science installation deployed across the Australian Outback to track meteoroids entering the Earth's atmosphere down to the ground. The camera network observes the meteors produced by the meteoroids as they ablate (burn up) in the atmosphere while slowing down from hypersonic velocities. Bright meteors like the kind that often produce meteorites (meteoroids that have made it all the way through the atmosphere to the Earth's surface) are called fireballs. Our camera's observe these fireballs from multiple locations which allows us to triangulate the trajectory through the atmosphere in three dimensions. This allows us to get a pre-atmospheric entry orbit (where it came from in the Solar System) and also estimate it's fall position and mass. We then conduct ground searches (usually on foot) in the Outback to recover the meteorites. Meteorites aren't particularly hard to come by (~50,000 in museum collections) but meteorites with orbits are extremely rare (about 20 in existence) and are much more valuable because we know where they come from, and they can potentially be matched up with a parent body.

Some coverage of our recent New Years Eve find:

http://mashable.com/2016/01/07/billion-year-meteorite-australia/#FImJtMyRhOqL

http://www.abc.net.au/pm/content/2015/s4384146.htm

http://www.sbs.com.au/news/article/2016/01/06/rare-meteorite-offers-clues-universes-formation

http://www.bbc.com/news/world-australia-35035714

We've got most of the team here answering questions starting at 0730 AWST (2330 UTC). Our flair indicates which part of the network we work on.

Proof: Robert along with an ABC news article

The Team (the photo is a little out of date though):

Phil Bland, Project Leader

rmhowie, Robert Howie, observatory design

Daly_Planet, Luke Daly, in situ analysis of nanometer scale structures in meteorites

morvan68, Martin Towner, network manager

ellieness, Ellie Sansom, trajectory modelling and mass estimation

haaadry, Hadrien Devillepoix, astrometry and lens calibration

PlanetOfLucy, Lucy Forman, lunar soils and micrometeorite analysis

Fireballsjay: Jay Ridgewell, community outreach coordinator

paxmaniac: Jon Paxman, engineering

Edit:

Thanks for all the questions! We're going back to work for now (got to get back to pushing back the frontiers of human knowledge :P), but we'll check back after work today and tomorrow, so feel free to put your question down below, we just won't be able to get back to it for a couple of hours.

And if you happen to see any fireballs... don't forget to report them on our app! http://fireballsinthesky.com.au/download-app/

Comments: 111 • Responses: 10  • Date: 

moustachaaa6 karma

Who owns the meteorite: you; your employer; or the Commonwealth?

FireballsSky7 karma

Meteorites remain the property of the State government. In this case the representative is the SA Museum. In WA its the WA Museum. As with all meteorites anywhere in the world that are in museum collections - whether they're one of the 20 with orbits, or one of the 50,000 without - scientists have samples on loan for their research, and then return them when their research is done.

wikibear20153 karma

what kind of interesting thing have you found about this meteorite that different from others we known about?

FireballsSky4 karma

Main thing is that we have an orbit, as well as the rock. The two together means that gradually, as we get more, we can build a geological map of the inner solar system.

DJ_0100103 karma

Where did you think the meteorite came from?

FireballsSky3 karma

It came in from around halfway between Mars and Jupiter and the orbit just touched our obit.

(Here is a picutre of the orbit](http://i.imgur.com/VNMwXrT.png) Jupiter's orbit is in orange; Mars is in red, and Earth is in light blue. The meteorite is in faded orange and dark blue.

Dittybopper2 karma

What happens to the meteorite now, and what do you expect to learn from it? Also, have any of what earthlings term precious metals been associated with meteorite finds, as in incorporated within the meteorite?

FireballsSky3 karma

Now we analyse the composition of the rock, and also try and pin down exactly where it came from - either a specific asteroid, or a specific part of the asteroid belt. There are only ~20 meteorites where we also have orbits. Every time we get a new one it tells us something new about the early solar system. As an example, the first one we ever got ended up giving us a clue about what the ingredients were that made the Earth. We never thought that that would be where it took us. Its always a surprise.

FeebleOldMan2 karma

Why did this AMA get removed?

FireballsSky2 karma

I think proof, but I've added it :S

FireballsSky2 karma

Thanks! We're back up! :)

OctopusOnTheRocks2 karma

Favorite beer?

FireballsSky1 karma

We did have this interesting "port" that was given to us by a station owner I think; /u/Daly_Planet can tell you more!

dolphinesque1 karma

How dangerous are meteoroids falling to earth? What are the chances of someone being struck by one and dying? I need something new and fresh to worry about.

How big is a typical meteorite?

FireballsSky1 karma

Unfortunately the chance of getting hit by a meteorite is incredibly unlikely, so I can't really give you anything to worry about.

The mass distribution is interesting most of the incoming extraterrestrial mass is from dust sized particles. /u/ellieness can probably chime in with a bit of info on the frequency of larger ones.

glidepath1 karma

How much mass do you estimate your meteorite lost in the process of traversing from the vacuum of space, through our atmosphere, and finally impacting earth?

FireballsSky2 karma

We have estimated that it hit the top of the Earth's atmosphere as an 80 kg object. This would not have changed since it broke away from its parent asteroid. The meteorite on the ground weighs 1.7 kg so it lost a lot. his can happen by both ablation (ionisation and melt droplets) and fragmentation (chucks breaking off).

glidepath1 karma

Is the meteorite like a blackbody radiation source? How far into the atmosphere does it reach its maximum temperature and what is a typical maximum temperature?

FireballsSky1 karma

No – a meteorite is not like a blackbody radiation source – it is composed of minerals and each one has it’s own emission spectrum which combine to form the emission (thermal IR) spectrum of the rock. As for how hot it gets, the speed at which they come in (this one at 14 km/s) compresses the air in front of them and causes the surface temperature to heat to over 2000 Kelvin. Temperature is not really cumulative, because anything that is heated above melting is pretty much removed immediately as it passes through the atmosphere, and thus the temperature is at it’s max as soon as it hits fireball stage.