October 19, 2014 could be a big day for Mars, and the robots that currently roam about its surface. According to preliminary observations, a newly discovered comet named C/2013 A1 may be on a crash course for our red neighbor. I came across this report from Discovery News this morning and found it to be terribly interesting! Projections right now have the comet missing the Red Planet by a mere 63,000 miles (for comparison, that's about 1/4 the distance between Earth and the Moon). Imagine a comet flying between Earth and the Moon! Picture how brightly it would light up the sky! Amazing!
At this point, it's unknown how large the comet is. Comets are smaller than planets, typically between a few hundred meters and several miles in diameter, so if it does impact the planet it won't destroy it. However, the impact would be devastating and would spur on a global event the likes of which nobody alive has ever seen. If the comet is a few miles in diameter, it would produce a crater some 10-30 miles miles in diameter and probably kick up enough debris to completely enshroud the planet. We would get a first-hand look at the awesome power of nature, and perhaps a glimpse into the potential future for our own Earth.
At this point, measurements are too few (and the interaction too far in advance) to accurately determine whether there will be an impact or not. As more observations are made, the window through which the comet will pass will become smaller as its orbit is more precisely defined. Even if the comet misses Mars, it is still bound to be an exciting event - and with any luck, some of those roaming robots will get an opportunity to turn their cameras skyward and snap an image of the passing interloper from the outer solar system.
Speaking of exciting events, comet C/2011 L4 (PANSTARRS) continues to grow in brightness. Images from several sources, including Spaceweather.com, show the comets tail growing with time as viewers in the Southern Hemisphere are already able to see it with the naked eye.
Southern Hemisphere viewers actually have two comets: PANSTARRS and Comet C/2012 F6 (Lemmon). This video created by Alex Cherney shows both comets visible. Look for one comet (PANSTARRS) on the left side of the frame, and the other (Lemmon) near top-center, displaying a nice green hue:
Comets Lemmon and PanSTARRS sweeping through the Southern Skies from Alex Cherney on Vimeo.
Two comets - C/2012 F6 (Lemmon) and C/2011 L4 (PanSTARRS) can be seen moving through the Southern Sky in this short time lapse video.
By mid-March, we in the Northern Hemisphere should get a glimpse of PANSTARRS, so hopefully my posts in the near future will contain my own images of the sight. Happy viewing!
