Comet C/2013 A1 possible Mars Strike in 2014
 

Would be interesting if it hit Phobos- I think that would shatter the moon...

A recently discovered comet will make an uncomfortably close planetary flyby next year — but this time it’s not Earth that’s in the crosshairs.
According to preliminary orbital prediction models, comet C/2013 A1 will buzz by Mars on Oct. 19, 2014. The icy interloper is thought to originate from the Oort Cloud — a hypothetical region surrounding the solar system containing countless billions of cometary nuclei that were outcast from the primordial solar system billions of years ago.
We know that comets have hit the planets before (re: the massive Comet Shoemaker–Levy 9 that crashed into Jupiter in 1994), Mars in particular.

C/2013 A1 was discovered by ace comet-hunter Robert McNaught at the Siding Spring Observatory in New South Wales, Australia, on Jan. 3. When the discovery was made, astronomers at the Catalina Sky Survey in Arizona looked back over their observations to find “prerecovery” images of the comet dating back to Dec. 8, 2012. These observations placed the orbital trajectory of comet C/2013 A1 through Mars orbit on Oct. 19, 2014.
Could the Red Planet be in for a potentially huge impact next year? Will Mars rovers Curiosity and Opportunity be in danger of becoming scrap metal?
It seems the likelihood of an awesome planetary impact is low — for now.

According to NASA’s Jet Propulsion Laboratory (JPL) calculations, close approach data suggests the comet is most likely to make a close pass of 0.0007 AU (that’s approximately 63,000 miles from the Martian surface). However, there’s one huge caveat.
Due to uncertainties in the observations — the comet has only been observed for 74 days (so far), so it’s difficult for astronomers to forecast the comet’s precise location in 20 months time — comet C/2013 A1 may fly past at a very safe distance of 0.008 AU (650,000 miles). But to the other extreme, its orbital pass could put Mars directly in its path. At time of Mars close approach (or impact), the comet will be barreling along at a breakneck speed of 35 miles per second (126,000 miles per hour). (~55km/s relative to Mars)
Also, we don’t yet know how big comet C/2013 A1 is, but comets typically aren’t small. If it did hit, the impact could be a huge, global event. But the comet’s likely location in 2014 is also highly uncertain, so this is by no means a “sure thing” for Mars impact (Curiosity, you can relax, for now).

A flyby of that distance will mean that should C3/2013 A1 erupt with a tail and coma around its nucleus (as it becomes heated by solar radiation), our Mars rovers and orbiting armada of planetary observation satellites will have a very intimate view of this historic moment. It has the potential to be a more impressive sight than Comet ISON’s inner-solar system trek later this year. But understanding the nature of comets is hard to predict; we won’t know if the sun’s heating will be sufficient enough for the comet nucleus to erupt and start out-gassing for some time to come.

I just ran it through the orbit simulator in the JPL Small Body Database Browser and the results are disturbing to say the least. :scared2:

Cheers -

Ooh, I have never seen the simulator do that before.
Very interesting to say the least. I would expect chance of impact to gradually reduce over time as they track it but still you never know.

Sorry Jarrod, my feeble attempt at humour. The simulator never does that, I blame idle hands and Photoshop... :whistle:

Cheers -

Its interesting though- the other orbital sims I have seen show the comet not traveling in the ecliptic plane but coming up from beneath it- perhaps its just a trick of perspective.

That doesn't make sense when some of the articles talk of a "head on" collision with the velocities of Mars and the comet combining to make the impact velocity of 55km/s. You know what these things are like- the media rarely gets it right, and space is large. Still if it did hit- what a show! Here's hoping Mars is on our nightside IF that happens- (goes to look up starry night for Oct 19th 2014)....

I also did some calcs looking at a potential Phobos impact. Real back of the envelop stuff considering we have no real idea how big the comet is. I put it at 2km diameter and mass equivalent of solid ice (Halley and Shoemaker-Levy (prior to break-up) are/were supposedly around 10-11km)- impacting on Phobos which is 11km dia and almost twice as dense as solid ice. Phobos is already supposed to have been weakened by the massive impact that formed Stickney crater. I feel fairly confident Phobos wouldn't survive a 55km/s impact with C/2013 A1. I'd love to hear from someone else who can do the arithmetic better though! If you do it as an inelastic collision, C/2013 A1 won't impart a whole lot of delta-v to Phobos, but Phobos as shrapnel would be another story entirely. We would get rings around Mars a whole lot sooner than the current forecast!

If we did get a collision I wonder if covering that big-a$$ sky would get a lot more funding. Diverting something with that much mass traveling that fast would be pretty hard to achieve in 18 months- that's 18 months INCLUDING the time taken for your equipment to be built and sent there. We've already seen some more money tipped in to detection following the pebble that blew up over Siberia last week.

As a footnote, Purdue university has a neat calc webpage (I've seen a better one somewhere else but the venerable Ron Baalke contributed to this one) that will tell you the effects of an impact on the Earth depending on how far you are from it and what it hits (crystalline or sedimentary rock, ocean strike etc.) For a 2km comet traveling that fast it's pretty interesting! You'd want to be more than 500km away and more than 100m above sea level.

Hi Brad - it's a 2-dimensional rendition and doesn't show perspective, so you can't tell from that whether the orbit's in the ecliptic plane or any other plane for that matter (other than the colour clue of the two shades of blue representing above & below the ecliptic). It's different in the database browser where you can toggle it around to get the perspective. :thumbsup:

Cheers -

Damn, I hope it misses. An impact (esp a collision with Phobos) could send debris right into our path.

Cheers
Steffen.

@ROB_K - try here, you can tilt and pan...

http://ssd.jpl.nasa.gov/sbdb.cgi?sst...og=0;cad=1#orb

:shrug: That's where I got the frames from - re-read my post, that's what I was saying to you. You indicated that my animation showed the orbit in the ecliptic plane while as presented it doesn't show it in any plane at all. Other than the flat plane of each frame I suppose... ;)

Cheers -

Nice info! I calculate orbit for this comet and it will reach -7.8 mag !!! from Mars and distance 118 370 km from Mars center at 19 Oct. 2014 at 21:12 UTC

Comet is big.

Well this thread has hit the bigtime !
It is now featured on Universetoday
Seems to me we are getting an increasing number of comets coming our way, makes me wonder ?

Yep, and I see they put a the size of the comet way, way larger than my measly 2km. If it is that big and it hits anything I'd imagine that would be pretty spectacular. Still, there is an awful lot of empty space within the current error margin. Hopes are not very high yet. Imagine the research you could do examining the results of such an impact.

So is therer any speculation about Mars' gravity altering the path to the point where it may place move into a more regular orbit (or dare I ask... a NEO / doomsday orbit) ?

Hey.. all those people carrying cardboard signs need something new to write... ha ha

With a fairly recent ephemeris, Starry Night's idea of what C/2013 A1 will look like from Planum Australe, Mars (about 80S 155W) 2014-10-20 05:54 UTC. Range 935409km. Apparent mag -3.54.

Here's a screen shot from TheSkyX of mars and the comet on 19 October 2014. Separated by 3 arc min. (obviously not the real separation)

Josh

Further developments:

http://spaceobs.org/en/2013/02/27/ne...13-a1-to-mars/

It's getting very interesting!!

Interesting indeed !
Maybe Curiousity with all it's cameras can take a few pix as it slides by. NASA must be having a few conniptions about both the opportunitiy and the dangers to their hardware. If it's as big as they are speculating how visible will it be from here and how close will it pass us by ?
Could be rather spectacular whatever happens.

It won't pass very close to us Brent - it will be way south of the Earth's orbital plane when it passes us. It also doesn't get very close to the sun so it probably won't be super bright either.

Bummer
 

According to this website, Mars will be visible pretty much only during the day from Australia in October 2014.

http://museumvictoria.com.au/planeta...te=19-Oct-2014

I tried generating a 3D plot with gnuplot from JPL ephemeris for the two. This is the closest they appear to get. They cross at close to 90° - Mars moving in RA, C/2013 A1 moving in Dec.

Z is in AU from the Sun.