Could Comet C/2013 A1 impact Mars in 2014?

[garyw]

There is a chance that the comet C/2013 A1 (Siding Spring), discovered in the beginning of 2013, might collide with Mars. At the moment, based on the observation arc of 74 days, the nominal close approach distance between the red planet and the comet might be as little as 0.00073 AU, that is approximately 109,200 km! Distance to Mars’ natural satellite Deimos will be smaller by 6000 km, making it 103,000 km. On the 19th October 2014, the comet might reach apparent magnitude of -8…-8.5, as seen from Mars! Perhaps it will be possible to accuire high-resolution images from the Mars Reconnaissance Orbiter (MRO).


Since C/2013 A1 is a hyperbolic comet and moves in a retrograde orbit, its velocity with respect to the planet will be very high, approximately 56 km/s. With the current estimate of the absolute magnitude of the nucleus M2 = 10.3, which might indicate the diameter up to 50 km, the energy of impact might reach the equivalent of staggering 2×10¹º megatonnes! This kind of event can leave a crater 500 km across and 2 km deep. Such an event would overshadow even the famous bombardment of Jupiter by the disintegrated comet Shoemaker–Levy 9 in July 1994, which by some estimates was originally 15 km in diameter.


All that is said above is based on the current measurements, and will of course be refined as more data comes in. In any case, even now we can say that the close approach will happen. The current orbit uncertainty allows for a collision scenario, but the possibility of this is small. Astronomers keep watching this interesting comet, and I will keep you up to date with the news.
Nominal orbital elements were taken from JPL NASA website, calculations were done in Mercury package.

Source: http://spaceobs.org/en/2013/02/25/comet-c2013-a1-siding-spring-a-possible-collision-with-mars/

Even if it's a miss it's going to be quite the science opportunity.

 

[4throck]

Forget the collision, that's sensationalist journalism for now. What's certain is that the comet will be close to Mars.

This would make an excellent scenario for Orbiter.... We just need to come up with an interesting story line to justify a rendezvous with the comet. :thumbup:

Let's see.. would the scientists on Olympus base be interested in retrieving comet samples ? I guess so....

 

[Urwumpe]

But you would need quite a lot of fuel I think for rendezvous with the comet... 56 km/s relative velocity is beyond the DV of the Deltaglider. At one g resulting acceleration, you would need over 90 minutes to reach that velocity.

 

[SolarLiner]

This would make an excellent scenario for Orbiter.... We just need to come up with an interesting story line to justify a rendezvous with the comet. :thumbup:

Let's see.. would the scientists on Olympus base be interested in retrieving comet samples ? I guess so....

56 km/s and return safely to Mars ? Hum ...
But the comet might be doable, I mean its tail, the collect with UMmu Action Areas ... But for a proper and realistic flight with a ship ...
Also how to find (and convert to Orbiter-friendly format) its orbital path (or elements ?)

 

[RisingFury]

I wonder if we could still expect a manned landing on Mars within our life time if something like that hit it. Even if we had the technology, I wonder if the surface conditions would allow a landing after several decades...

 

[4throck]

OK, I admit I didn't check the maths on this one...
I assumed that since you can rendezvous with Halley with no problem, this would be the same.

From what you describe, it does seem more interesting to me!

In fact, why not launch a rocket with a lander from Mars instead of a DG?
Perhaps an unmanned probe ?

(I'm not saying that it makes sense, just that it looks interesting to me :thumbup

 

[BruceJohnJennerLawso]

I wonder if we could still expect a manned landing on Mars within our life time if something like that hit it. Even if we had the technology, I wonder if the surface conditions would allow a landing after several decades...

What changes would we expect at the surface if it did hit?

 

[statickid]

Is the orbiter in a high enough orbit to survive and document such an event? that would be INCREDIBLE if it could. I wonder if MSL would be ok if it was on the opposite side of the planet.

 

[RisingFury]

What changes would we expect at the surface if it did hit?

With the energy this thing would have on impact, I imagine that the crater would be very large and the impact powerful enough to melt a decent size of the crust around the impact zone.

The atmosphere would also take a hit. Weather and climate would change and I'm not sure how much dust would be thrown into the atmosphere and how long it'd stay up.

In addition to that, not only the impact site would be affected. I imagine debris would be thrown far out into space. Some would escape Mar's influence, but some would rain back down on other parts of the planet...

The shockwave from the impact would also be present. A thousand years ago, the Moon was struck by a large impactor and it still shakes from that impact...



That said, I'd LOVE to see it happen.

 

[dgatsoulis]

Now THAT is one heck of trajectory planning exercise. Unfortunately there is no time to plan anything realistic for the 2014 encounter.

If there was sufficient time, the only way that would make sense (at least to me) would be an Earth-Jupiter-Jupiter(½ orbit)-Mars plan, in order to get spacecraft into a retrograde heliocentric trajectory.

Also how to find (and convert to Orbiter-friendly format) its orbital path (or elements ?)

You can get the ephemeris (in Orbiter-friendly format) from JPL's HORIZONS system.

You will need these settings:

Ephemeris Type:   VECTORS
Target Body:   Comet C/2013 A1 (Siding Spring)
Coordinate Origin:   Solar System Barycenter (SSB) [500@0]
Time Span:   Start=(date), Stop=(date), Step=(# of days)
Table Settings:   output units=KM-S; quantities code=2
Display/Output:   default (formatted HTML)

Once you generate the ephemeris you can pick a date and get the position and velocity (almost) in Orbiter format. After that, you will need three things:

1. Convert the date to MJD
2. Convert km-km/s to m-m/s
3. Swap the Y and Z coordinates because Horizons uses a right-handed coordinate format and Orbiter uses a left-handed one. (Thanks to Ajaja for showing me that last one).

Here is an example:
HORIZONS:

[COLOR="DarkRed"]2456293.500000000 = A.D. 2013-Jan-01 00:00:00.0000 (CT) [/COLOR]
   1.546259160262450E+08  [COLOR="Blue"]8.212831296466637E+08[/COLOR] [COLOR="Green"]-6.850058151483121E+08[/COLOR]
   3.035445290961618E+00 [COLOR="blue"]-1.423560262633890E+01[/COLOR]  [COLOR="green"]5.825490552183194E+00[/COLOR]

Orbiter scenario (Deltaglider on the same trajectory):

BEGIN_ENVIRONMENT
  System Sol
  Date MJD [COLOR="DarkRed"]56293.000000[/COLOR]
END_ENVIRONMENT

BEGIN_SHIPS
Comet:DeltaGlider
  STATUS Orbiting Sun
  RPOS  1.546259160262450E+[COLOR="Red"]11[/COLOR] [COLOR="green"]-6.850058151483121E+[/COLOR][COLOR="red"]11[/COLOR] [COLOR="blue"]8.212831296466637E+[/COLOR][COLOR="red"]11[/COLOR] 
  RVEL 3.035445290961618E+[COLOR="red"]03[/COLOR] [COLOR="green"]5.825490552183194E+[/COLOR][COLOR="red"]03[/COLOR] [COLOR="blue"]-1.423560262633890E+[/COLOR][COLOR="red"]04[/COLOR]  
END
END_SHIPS

I'll try to set it up as a scenario and post it in the tutorials and challenges. I am thinking that 10 years before the Mars encounter will be enough time to find a plan that works.

One thing I am not sure about is which "Coordinate Origin" to use in Horizons, to get the trajectory accurately in Orbiter.
Sun Center or Solar System Barycenter? I am guessing the second one, but I'd appreciate it if anyone can confirm.

 

[Ajaja]

One thing I am not sure about is which "Coordinate Origin" to use in Horizons, to get the trajectory accurately in Orbiter.
Sun Center or Solar System Barycenter? I am guessing the second one, but I'd appreciate it if anyone can confirm.

I think "Sun Center". RPOS/RVEL means position/velocity relative to reference - Sun but not SSB, Earth but not Earth-Moon barycenter.

 

[Evil_Onyx]

Using upper estimates of 50km core at a 15 degree impact at 56 km/s.

According to an online calculation
The impact will have Energy of abouts 1.03 x 10^26 Joules = 2.45 x 10^10 MegaTons TNT

Leaving a crater of between 180 to 370 km wide.

It would be interesting to watch it but still...

 

[sorindafabico]

The shockwave from the impact would also be present. A thousand years ago, the Moon was struck by a large impactor and it still shakes from that impact...

What impactor?

 

[Sky Captain]

It would be spectacular event if it hits. Imagine all the scientific data that could be gathered from monitoring the impact in real time. Some of the Mars terraforming scenarios calls for bomabrding Mars with comets to heat it up and relese CO2. A natural impact would show if it is viable or not. An impact of that size would launch some Martian debris above escape velocity so it is possible Earth would get fresh samples of Martian rocks. And a crater would expose fresh rock layers making the impact site a treasure for any future missions.

 

[SpaceEagle]

Then MRO will find water on Mars,the impacts heat may melt the ice,then our landers and rovers would be washed as hell (It might cause a tsunami with the melted water i think)
Then we only need oxygen,nitrogen and other stuff up the atmosphere. We get life.

 

[Athena]

Then MRO will find water on Mars,the impacts heat may melt the ice,then our landers and rovers would be washed as hell (It might cause a tsunami with the melted water i think)
Then we only need oxygen,nitrogen and other stuff up the atmosphere. We get life.

Life doesn't just start as magic. And the ice is mostly on the poles and made of CO2 so it'll more likely evaporate into a gas, thicken the atmosphere, better greenhouse effect, higher mean surface temperature. But you will need to hold that atmosphere together, which, unfortunately, Mars can't do right now.

 

[IronRain]

Then MRO will find water on Mars,the impacts heat may melt the ice,then our landers and rovers would be washed as hell (It might cause a tsunami with the melted water i think)
Then we only need oxygen,nitrogen and other stuff up the atmosphere. We get life.

I'm afraid you've played the game "Spore" too much :lol:

 

[garyw]

Then MRO will find water on Mars,the impacts heat may melt the ice,then our landers and rovers would be washed as hell (It might cause a tsunami with the melted water i think)

Not a chance. Mars atmosphere is still way to thin to hold on to liquid water. Any water that is released will very quickly boil away.

Then we only need oxygen,nitrogen and other stuff up the atmosphere. We get life.

Life is much more complex than that. You need a lot more to create life, if it were that simple various experiments carried out in labs the duplicate early Earth would have created life but so far all have failed.

 

[Urwumpe]

Also, I would not overestimate how much water the poles of Mars hold. It wouldn't be a tsunami, but rather wet your feet.

 

[SpaceEagle]

I'm afraid you've played the game "Spore" too much :lol:

I even don't know that game.