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October 19, 2014.
50km (31 miles) in diameter and moving at 56kps (125,268 mph), resulting in a crater 500km (310 miles) across it if hits. That's the distance from here to Lubbock.
50km (31 miles) in diameter and moving at 56kps (125,268 mph), resulting in a crater 500km (310 miles) across it if hits. That's the distance from here to Lubbock.
Comet C/2013 A1 (Siding Spring) – a possible collision with Mars
February 25th, 2013
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 from 10 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.
February 25th, 2013
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 from 10 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.
Update on Comet C/2013 A1 (Siding Spring) and a possible Mars Impact
You may remember I posted about a possible impact of the newly discovered comet C/2013 A1 (Siding Spring) with Mars. At the time, although an impact was possible the nominal orbit was pretty far from Mars.
Now after some more observations and refinement of the orbit, the orbital track has moved in a bit.
The nominal close approach is now 0.0007 AU. This is much closer than the previous 0.006 AU, but still further out than the 0.00023 AU close approach of 2012 DA14, which missed us by two Earth diameters.
The error associated with this estimate still includes an impact though (and a maximum miss of 0.008 AU), so an impact can't be ruled out at this stage.
As I wrote before, as further observations are added and the orbit is refined, we will have a better idea of whether it will impact. Even if it doesn't impact it will look pretty good from Earth, and specacular from Mars (probably a magnitude -4 comet as seen from Mars's surface), which might be observed by the plethora of orbitig spacecraft and the rovers. A collision would also be spectacular, but the rovers may not fare so well.
You may remember I posted about a possible impact of the newly discovered comet C/2013 A1 (Siding Spring) with Mars. At the time, although an impact was possible the nominal orbit was pretty far from Mars.
Now after some more observations and refinement of the orbit, the orbital track has moved in a bit.
The nominal close approach is now 0.0007 AU. This is much closer than the previous 0.006 AU, but still further out than the 0.00023 AU close approach of 2012 DA14, which missed us by two Earth diameters.
The error associated with this estimate still includes an impact though (and a maximum miss of 0.008 AU), so an impact can't be ruled out at this stage.
As I wrote before, as further observations are added and the orbit is refined, we will have a better idea of whether it will impact. Even if it doesn't impact it will look pretty good from Earth, and specacular from Mars (probably a magnitude -4 comet as seen from Mars's surface), which might be observed by the plethora of orbitig spacecraft and the rovers. A collision would also be spectacular, but the rovers may not fare so well.
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