Recent comet sightings and the fiery path blazed across Russian skies by a large meteor have people pondering the possibility of a collision between Earth and some other heavenly body. Lost in the discussion is news from NASA that Mars is on schedule for a close encounter of its own in 2014, and the visiting comet may actually strike the red planet. Comet C/2013 A1 (Siding Spring) will be rendezvousing with Mars in October 2014, most likely passing by the planet at roughly the height of an earthly communication satellite. Estimates of the minimum distance between planet and comet range from about 100,000 km and 0, meaning a collision. If the comet does collide with Mars it is estimated the blast will be equivalent to that of a billion megatons of TNT. It would be an event of the same magnitude as the impact that killed off the dinosaurs 65 million years ago.
The recent meteor break-up over Russia, and the close pass of asteroid 2012 DA14, serve to reminded people that all objects in the solar system are subject to the occasional collision. A look at the surface of Earth's Moon, or the surface of Mars, gives ample evidence of collisions past. Lest we think it can't happen to us, Earth's surface also bares the scars of bombardment from space.
For example, the Manicouagan Crater, located in Canada, is one of the oldest known impact craters on Earth (see the image below). It is thought to have been caused by the impact of a 5 km (3 mi) diameter asteroid about 215.5 million years ago, during the Triassic Period. The crater is a multiple-ring structure about 100 km (60 mi) across, with its 70 km (40 mi) diameter inner ring its most prominent feature.
If such an impact event happened today human civilization would certainly fall and H. sapiens would be lucky to avoid extinction. But surely governments have programs to detect such dangerous interlopers from deep space in time for us to take action, right? While it is true that observation programs do exist and scientists have labored for years to create a catalog of objects large enough to cause extinction level events, the list is far from exhaustive. For example, there was that recent event over Russia on February 26th. Here is how NASA's Science News reported the events of that day.
Feb. 26, 2013: When the sun rose over Russia's Ural Mountains on Friday, Feb. 15th, many residents of nearby Chelyabinsk already knew that a space rock was coming. Later that day, an asteroid named 2012 DA14 would pass by Earth only 17,200 miles above Indonesia. There was no danger of a collision, NASA assured the public.
Maybe that's why, when the morning sky lit up with a second sun and a shock wave shattered windows in hundreds of buildings around Chelyabinsk, only a few people picking themselves off the ground figured it out right away. This was not a crashing plane or a rocket attack.
In a coincidence that still has NASA experts shaking their heads, a small asteroid completely unrelated to 2012 DA14 struck Earth only hours before the publicized event. The impactor flew out of the blue, literally from the direction of the sun where no telescope could see it, and took everyone by surprise.
In other words, Earth was struck by an undetected meteor that no one expected. Preliminary reports suggest that the asteroid was made mostly of stone with a bit of iron. “A typical asteroid from beyond the orbit of Mars,” said Bill Cooke of NASA's Meteoroid Environment Office. “There are millions more just like it.” For the complete story see the video below.
Suffice it to say, we could still be struck by a cataclysmic cosmic event with little or no warning. But the planet in immediate peril is Mars, not Earth. It seems that the red planet is being menaced by daemons from the Kuiper Belt. The discovery of comet C/2013 A1 (Siding Spring) was announced on Cbet nr. 3368 & M.P.E.C. 2013-A14, issued on January 5, 2013. The comet was discovered on CCD images obtained by notable Australian observer R. H. McNaught with the 0.5-m Uppsala Schmidt telescope at the Siding Spring Observatory in Australia. According to the Remanzacco Observatory web page:
It has been noted that C/2013 A1 will have a very close approach with planet Mars on October 19, 2014. With an observation arc thus far of 148 days, JPL/NASA give a nominal closest approach of ~0.0003578 A.U. which is around 53,500 km on 2014 Oct. 19 at approximately 19:28UT +/- 1:03. The comet will pass Mars at a relative velocity of 56 km/s. Early estimates for the diameter of the nucleus have varied from 5 up to 50 km.
NASA/JPL Near-Earth Object Program verifies that the comet will pass extraordinarily close to Mars, almost certainly within 300,000 km of the planet and possibly much closer. “Our current best estimate has it passing about 50,000 km from the surface of Mars,” a press release said. “This is about 2.5 times the distance of Mars' outermost satellite Deimos or less than twice the Earth close approach distance of 2012 DA14 on February 15, 2013.” NASA has provided the diagram below showing the comet's path through the inner solar system.
There is also an interactive orbit visualization tool available that can be used to track the comet's path as it approaches Mars. Since the observation data available for orbit determination is limited, and the current orbit is quite uncertain, the approach distance will probably change as additional observations are made. “Currently, Mars lies directly within the range of possible paths for the comet and we can't exclude the possibility that the comet might impact Mars,” the report goes on. “Our current estimate for the impact probability is less than one in six hundred.”
What does the daemon from deep space look like from Earth? Below you can see an animation spanning 25 minutes that shows the movement of comet C/2013 A1. It is composed of 11 exposures, each of 80 seconds duration. The images were taken in collaboration with the Faulkes Project and Horbury Academy. The comet is the faint dot located in the middle of the frame, moving toward the upper right corner. [See Source link for this]
NASA scientists are almost giddy over the possibility that the spacecraft currently orbiting Mars and the rovers on the martian surface might be able to observe the encounter. The rovers, Opportunity and Curiosity, should get some spectacular pictures to send back to Earth. As Donald Yeomans of NASA says, “unless this comet completely fizzles, it should be extraordinary as seen with Mars-based assets.” The NASA plot below, prepared by Jon Giorgini, shows the apparent total visual magnitude and solar elongation angle as seen from the center of Mars.
According to NASA:
During the close Mars approach, the comet will likely achieve a total visual magnitude of zero or brighter as seen from Mars-based assets. The attached illustration shows the comet's approximate, apparent visual magnitude and its solar elongation angle as a function of time as seen from Mars. Because the comet's apparent magnitude is so uncertain, the brightness curve was cut off at apparent visual magnitude zero. However, the comet may get brighter than magnitude zero as seen from Mars. From Earth, the comet will not likely reach naked eye brightness but it could brighten to visual magnitude 8 as seen from the southern hemisphere in mid-September 2014.
At the very least, NASA and the European Space Agency (ESA), which also has a satellite orbiting Mars, will get an unexpected close look at the comet. At most, scientists might get to see the creation of a giant crater. If the comet impacts the surface of Mars, telescopes on Earth and in orbit will be able to observe a large-scale cratering event in real time. Telescopes orbiting Mars will get an even better view, though perhaps at their own peril. The amount of debris thrown up from the planet’s surface and into space could be quite hazardous to any spacecraft orbiting the red planet, and more than a billion dollars worth of spacecraft might be lost as a result.
The cratering process would be of great interest to geologists and what follows would be even more so to astrobiologists. The Martian crust contains a lot of water ice and the enormous heat of the impact would melt a huge volume of it. For a brief period, liquid water would flow again on the surface of Mars.
If there are microbes living deep under the Martian surface, the return of warm, wet conditions would give them a brief chance to live at or near the surface. Moreover, parts of the surface and subsurface in the impact region would stay warm for decades. Strange how such a potentially life threatening event, should something similar happen on Earth, could finally answer the question of life on Mars.
There are lessons here for those of us stuck on this planet. First and foremost, that objects from space pose a real danger to life on Earth—a much greater threat than any of the improbable disasters predicted by climate change alarmists. The possibility that the ocean may rise by a few centimeters pales in comparison to a major impact event. Yet Gaia worshiping, tree-huggers demand we spend “whatever it takes” to reverse global warming, when what we should really be doing is spending money on a space program that can detect and deflect incoming objects.
Better yet, we should be actively trying to get to other planets. It is an old saying, “Earth is just too small and fragile a basket for mankind to place all its eggs.” Until humans become a multi-planet species extinction is only an asteroid strike away. Grant-money grubbing climate scientists, dingbat ecologists and chucklehead politicians bemoan the dangers of climate change when nature could suddenly change Earth's climate more drastically than anything in the IPCC's book of horrors. I know where I want my tax money to go, and it isn't to subsidies for windmills or failed solar energy companies. Remember, Earth has been struck many times before and will be again—just ask the dinosaurs how that worked out for them.
Be safe, enjoy the interglacial and stay skeptical.