FIRE IN THE SKY: Major Solar System Disturbance - Newly Found Asteroid To Pass Within Moon’s Orbit On March 4, 2013 And Newly Discovered Comet May Be On Explosive Collision Course With Mars In October 2014?!

March 04, 2013 - SPACE - A newly found asteroid will pass just inside the orbit of the Moon, with its closest approach on March 4, 2013 at 07:35 UTC. 

Newly Found Asteroid To Pass Within Moon’s Orbit On March 4, 2013.

Named 2013 EC, the asteroid is about the size of the space rock that exploded over Russia two and a half weeks ago, somewhere between 10-17 meters wide (the Russian meteorite is estimated to be about 15 meters wide when it entered Earth’s atmosphere). 2013 EC was discovered by the Mt. Lemmon Observatoryin Arizona on March 2. . There is no chance this asteroid will hit Earth.

2013 EC will come within 396,000 kilometers from Earth, (246,000 miles, or around 1.0 lunar distances, 0.0026 AU. 

The Moon’s distance from the Earth varies between 363,104 km (225,622 miles) at perigee (closest) and 406,696 km (252,088 miles) at apogee (most distant point).

A newly found asteroid, 2013 EC can be seen in the lower left corner of the red box in this image.
Screen capture from Virtual Telescope webcast on 3/3/2013.

Gianluca Masi from the Virtual Telescope Project had a live view of the asteroid when it was about twice the distance of the Moon, and a replay of that webcast is available below. 

“That we are finding all these asteroids recently does not mean that we are being visited by more asteroids,” Masi said during the webcast, “just that our ability to detect them has gotten so much better. Our technology has improved a lot over the past decades.”

More info about 2013 EC on the JPL Small Body Database. - Universe Today.

Newly Discovered Comet May Be On Explosive Collision Course With Mars In October 2014.

There is an outside chance that a newly discovered comet might be on a collision course with Mars. Astronomers are still determining the trajectory of the comet, named C/2013 A1 (Siding Spring), but at the very least, it is going to come fairly close to the Red Planet in October of 2014. "Even if it doesn't impact it will look pretty good from Earth, and spectacular from Mars," wrote Australian amateur astronomer Ian Musgrave, "probably a magnitude -4 comet as seen from Mars's surface."

Simulation of the close approach of C/2013 A1 to Mars in Celestia using the latest info from the Minor Planet Center. Credit: Ian Musgrave/Astroblog.

 The comet was discovered in the beginning of 2013 by comet-hunter Robert McNaught at the Siding Spring Observatory in New South Wales, Australia. According to a discussion on the IceInSpace amateur astronomy forum when the discovery was initially 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 right through Mars orbit on Oct. 19, 2014. However, now after 74 days of observations, comet specialist Leonid Elenin notes that current calculations put the closest approach of the comet at a distance of 109,200 km, or 0.00073 AU from Mars in October 2014. That close pass has many wondering if any of the Mars orbiters might be able to acquire high-resolution images of the comet as is passes by. 

Fragments of Shoemaker-Levy 9 on approach to Jupiter. Credit: NASA/HST.

But as Ian O'Neill from Discovery Space points out, since 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)," Ian wrote, "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)." 

Elenin said that 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 megatons!" An impact of this magnitude would leave a crater 500 km across and 2 km deep, Elenin said. 

While the massive Comet Shoemaker–Levy 9 (15 km in diameter) that crashed into Jupiter in 1994 was spectacular as seen from Earth orbit by the Hubble Space Telescope, an event like C/2013 A1 slamming into Mars would be off the charts. Astronomers are certainly keeping an eye on this comet, and they will refine their measurements as more data comes in. You can see the orbital parameters available so far at JPL's Solar System Dynamics website. - PHYSORG.