Comet Just Might Hit Mars In 2014

[Ryan Ruck]

Comet Just Might Hit Mars In 2014

February 27, 2013

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, probably a magnitude -4 comet as seen from Mars' surface," Australian amateur astronomer Ian Musgrave wrote.

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 "pre-recovery" 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, after 74 days of observations, comet specialist Leonid Elenin notes that current calculations put the closest approach of the comet at a distance of 67,853 miles (109,200 kilometers), 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 it passes by.

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 precisely where the comet will be 20 months from now. "Comet C/2013 A1 may fly past at a very safe distance of 0.008 AU (650,000 miles)," O'Neill 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 kilometers per second (126,000 mph). "With the current estimate of the absolute magnitude of the nucleus M2 = 10.3, which might indicate the diameter up to 50 kilometers [30 miles], the energy of impact might reach the equivalent of staggering 2×10^10 megatons!"

While the massive Comet Shoemaker–Levy 9 (9.3 miles or 15 kilometers in diameter) that crashed into Jupiter in 1994 was spectacular as seen from Earth orbit by the Hubble Space Telescope, the sight of 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.

[American Patriot]

Holy CRAP!

"...the energy of impact might reach the equivalent of staggering 2×10^10 megatons!"

That is 20,000,000,000 or 20 billion megatons.

That seems... high.

And scary! lol

[Ryan Ruck]

I'm thinking an impact that big could put even us at risk if Earth travels through the ejecta.

[American Patriot]

Probably a slim chance of that happening, but you never know.

[American Patriot]

By the way, thought I'd look this up again:

Nuclear testing has also been used for clearly political purposes. The most explicit example of this was the detonation of the largest nuclear bomb ever created, the 50 megaton Tsar Bomba, by the Soviet Union in 1961. This weapon was too large to be practically used against an enemy target, and it is not thought that any were manufactured except the one detonated in the test.

At Chicxulub (crater; meteorite that destroyed the dinosaurs):

The impactor had an estimated diameter of 10 km (6.2 mi) and delivered an estimated energy equivalent of 100 teratons of TNT (4.2×10²³ J).^[21] By contrast, the most powerful man-made explosive device ever detonated, the Tsar Bomba, had a yield of only 57 megatons of TNT (2.4×10¹⁷ J),^[22] making the Chicxulub impact 2 million times more powerful. Even the most energetic known volcanic eruption, which released approximately 240 gigatons of TNT (1.0×10²¹ J) and created the La Garita Caldera,^[23] was substantially less powerful than the Chicxulub impact.

For comparison... 240 gigatons is the same as 240,000 megatons. So the volcanic eruption above at 240,000 megatons was "small" in comparison to Chicxulub.

Chicxulub was probably formed by a rock as much as six miles across and the amount of energy release equivalent to around 100 million megatons. That should be 100,000,000 megatons.

1 megaton is 1 million tons of TNT.

so another three zeros added on it looks like.

Chicxlub =====1,000,000,000 megatons = 1,000,000,000,000 tons of TNT
Mars impact ==20,000,000,000 megatons =20,000,000,000,000 tons of TNT

As I said, this seems... "Really, really high" to me, unless I made a mistake someplace. Though I am pulling all my data from various locations and perhaps any of them are wrong or the estimate on Chicxulub are way off.

Either way, if such an impact occurs on Mars - Mars will become uninhabitable for centuries and there will be a huge volcanic crater that will be live and bubbling for a long time to come visible from Earth to telescopes large enough to make out details (And noted it's already "uninhabitable"). On the other hand, there isn't much of an atmosphere and the likelihood of massive ejection of matter into space is very great.

This will be... a spectacle we wouldn't want to miss.

Update Edit: A mile-wide asteroid would yield in the 1 million megaton range. An asteroid that size has energy that's 10 million times greater than the bomb that fell on Hiroshima. It's able to flatten everything for 100 to 200 miles out from ground zero. In other words, if a mile-wide asteroid were to directly hit New York City, the force of the impact probably would completely flatten every single thing from Washington D.C. to Boston, and would cause extensive damage perhaps 1,000 miles out -- that's as far away as Chicago. The amount of dust and debris thrown up into the atmosphere would block out the sun and cause most living things on the planet to perish. If an asteroid that big were to land in the ocean, it would cause massive tidal waves hundreds of feet high that would completely scrub the coastlines in the vicinity.

[American Patriot]

Damn... I wouldn't be safe in the ocean from an ocean impact... check this out:

Tsunami

The oceans cover about 75% of the Earth's surface, so it is likely the asteroid will hit an ocean. The amount of water in the ocean is nowhere near large enough to "cushion" the asteroid. The asteroid will push the water aside and hit the ocean floor to create a large crater. The water pushed aside will form a huge tidal wave, a tsunami. The tidal wave height in meters = (distance from impact)^-0.717 × (energy of impact)^0.495/ (10^10.17). What this means is that a 10-km asteroid hitting any deep point in the Pacific (the largest ocean) produces a megatsunami along the entire Pacific Rim.

Some values for the height of the tsunami at different distances from the impact site are given in the following table. The heights are given for the two typical asteroids, a 10-kilometer and a 1-kilometer asteroid.

Distance (in km)	10 km	1 km
300	1.3 km	43 m
1000	540 m	18 m
3000	250 m	3 m
10000	100 m	3 m

The steam blasts from the water at the crater site rushing back over the hot crater floor will also produce tsunamis following the initial impact tsunami and crustal shifting as a result of the initial impact would produce other tsunamis---a complex train of tsunamis would be created from the initial impact (something not usually shown in disaster movies).

======

At 300 miles from ground zero, the tsunami would be 300 meters high! (for a 1 km wide rock - that's about .6 mile)

at 3000 miles away (say on one side of the Pacific) the tsunami in the ocean would be 9 or 10 feet high... I can ride out 20' waves with no trouble but not a 900' high wave. lol

[American Patriot]

http://www.astronomynotes.com/solfluf/s5.htm

[Malsua]

Actually, a 300m tsunami in the middle of the ocean...hmm...it might just be a big swell. Seriously. The amplitude goes down...as long as your in water deeper than the amplitude, the surface probably wouldn't rise all that much.

[Malsua]

There were some fishermen in a Tsunami in Alaska in the 50s...if i recall the wave height was like 1/3 of a mile. They "rode it out". lol. What a ride.

[American Patriot]

Actually, a 300m tsunami in the middle of the ocean...hmm...it might just be a big swell. Seriously. The amplitude goes down...as long as your in water deeper than the amplitude, the surface probably wouldn't rise all that much.

Different kind of tsunami than a quake type.

And I do understand that if you're in the ocean and a quake occurs nearby that you're probably going to see a ripple on the ocean. When the energy gets near the shore and the land starts to rise up so does the energy.

With a hit from a meteor in the middle of the ocean there is a - for lack of a better explanation - a big "splash".

Try it yourself in a bucket or tub of water. Drop something in it (large/heavy) and you'll see the big "wave".

Then put your hand under the water and make an underwater "waveform" and you'll see the difference.

[American Patriot]

1/3 of a mile is high. Yikes. lol

I think the biggest waves I've been in thus far on a small boat (40') were probably 12 feet(ish). Nothing bad I thought. I was in bigger stuff above an A/C carrier once approaching Virginia off the coast. I believe we landed on the ship on the east side of the Gulf Stream (I'm not sure, I never saw charts so I'm guessing, but we were a day or so out) and then crossed the Stream with a northerly wind (which causes waves to build against the current going north, wind going south) but on the deck of the carrier they were insignificant to us.

[Malsua]

Found it.

http://en.wikipedia.org/wiki/1958_Li...ay_megatsunami <--big splash

[American Patriot]

Found it.

http://en.wikipedia.org/wiki/1958_Li...ay_megatsunami <--big splash

Right... so it looks like to ME from the description this was an underwater quake, which in turn shook lose a LOT of ice off a glacier.

That ice hitting the water would have generated a different set of waves from the quake itself. One event caused by the other, but causing to different types of water events. The quake causing a "megatsunami" and the fisherpeople experiencing the waves from the land mass falling into the water near by (six miles away).

I dunno though. I have been in a few quakes now, two pretty big ones, both of them on the coast, and neither generated a tsunami due to the actual location of the epicenter.

I just know the physics of an underwater quake and I know what you get when you throw a stone in the water. They are different events causing different results.

[Ryan Ruck]

Have fun!



http://www.purdue.edu/impactearth

[American Patriot]

Monster Comet may have Mars in its Crosshairs

Posted by Andrew Fazekas in StarStruck on March 6, 2013



Comet Siding Spring may be quite a sight in Martian skies in October 2014. Artwork courtesy of Kim Poor.



Mars may have a really bad day next year on October 19th. That’s when there is a very slight chance a newly discovered comet may impact our neighboring planet, says NASA.


Comet C/2013 A1 (Siding Spring) was discovered by Australian Robert H. McNaught, a prolific comet and asteroid hunter just two months ago and NASA’s Near-Earth Object Program Office at the Jet Propulsion Laboratory , in Pasadena, Calif., has been constantly refining the comet’s exact trajectory ever since.


Latest orbital calculations have the icy visitor passing by Mars at only 31,000 miles (50,000 kilometers) – only two-and-a-half times the distance that the outer moon Deimos orbits.


A giant comet is heading for a close encounter with the planet Mars in October 2014. Image courtesy of NASA/JPL


Astronomers watching the icy interloper predict that as more observations are accumulated over time, it’s more and more likely Mars is going to dodge the bullet and only get a close shave . The possibility of impact however has not been completely ruled out yet, says NASA, giving the comet a 1 in 600 chance of walloping the Red Planet.


If Siding Spring would hit, the force of impact may truly be monumental. Based on observations to date the comet nucleus could be a real monster – as big as 9 miles (15 km) to 31 miles (50 km) wide. With it’s velocity clocked at 35 miles (56 km) per second, the energy force of the collision could be measured in the billions of megatons, resulting in a crater hundreds of miles wide. This could be an impact that rivals the one that wiped out the dinosaurs 65 million years ago on our planet and would be bright enough to be even seen with the naked eye from Earth. (See “Russian Meteorite Spotlights History’s Other Crashes.”)


Chances are however that it will just barely miss the planet, but comet Siding Spring may still become visible through binoculars and backyard scopes for us Earthlings in the Southern Hemisphere around mid-September 2014. It should also produce quite a sky show as seen from the surface of Mars. (See: New Comet Discovered—May Become “One of Brightest in History”)


Current brightness magnitudes estimate that the comet will be very bright to even the digital eyes of the two working Mars rovers – Opportunity and Curiosity. Can hardly wait to see the amazing photos from these intrepid robotic explorers!


So it will definitely be worth watching what the comet does in the coming weeks and months- whether it impacts Mars or not.

[American Patriot]

Comet Siding Spring To Pass Close To Mars In 2014

March 5, 2013

Image Credit: Photos.com
Lee Rannals for redOrbit.com – Your Universe Online



We’ve had our fair share of close calls from asteroids recently, but a neighboring planet will soon have its day in the spotlight as a comet grazes past it.


Mars will have a front row ticket to comet 2013 A1 as it passes by the Red Planet in 2014, passing within 186,000 miles of Mars, according to NASA’s Near-Earth Object Program Office at the Jet Propulsion Laboratory in Pasadena, California. The office even said there is a strong possibility the comet could pass by the Red Planet within about 31,000 miles, which is just a little more than the distance between Earth and some of our communication satellites.


Comets are hard for astronomers to predict, and current estimates are based on October 2012 observations. NASA said further refinement of its orbit is expected to be made as more observational data is obtained, adding the possibility of comet 2013 A1 impacting the surface of Mars cannot be excluded.


“However, since the impact probability is currently less than one in 600, future observations are expected to provide data that will completely rule out a Mars impact,” NASA said.


The comet has been on a million-year journey to finally arrive to the inner workings of our solar system. 2013 A1, or Siding Spring, could feature volatile gases that short period comets often lack due to their frequent returns to the sun’s neighborhood.


If comet Siding Spring actually impacted Mars next year, scientists believe it could equal about 20 billion kilotons of TNT, or about 1,600,000 atomic bombs. The comet is predicted to be roughly between 12.5 to 25 miles in diameter.


Robert McNaught discovered the comet back in January at the Siding Spring Observatory in Australia. He has discovered 74 comets and 467 asteroids.


Although an impact is unlikely to occur on Mars next year, the astronomical event could still offer up some great opportunities for observations. The tail of the comet can spread across an area of hundreds of thousands of miles, so when a planet the size of Mars passes through the coma, it could provide outstanding eye candy in the sky. An atom in the coma colliding with an atom on Mars’ atmosphere would be heated to the temperature of the Sun’s corona, producing bright aurora-like lights.


Mars isn’t the only planet being treated to a spectacular view of a comet in the coming months, and days. Comet STARRS C/2011 L4 is making its way towards Earth and will be offering backyard astronomers a naked-eye view in the next week. Then, later this year, comet ISON will be potentially creating a once-in-a-lifetime sky show.


Comet ISON will be lighting up the sky as it approaches in November, potentially even becoming as bright as the moon in our sky. This comet will be traveling through the sun’s atmosphere on November 28 of this year, and it could be so bright it is visible during the day for a short amount of time. However, due to the unpredictability comets have to offer, all of these expectations could be more fluff than fact.
“I’m old enough to remember the last ‘Comet of the Century’. It fizzled. Comets are notoriously unpredictable,” said Don Yeomans of NASA’s Near-Earth Object Program.


“Whatever happens, northern sky watchers will get a good view,” NASA officials said. “For months after it swings by the sun, Comet ISON will be well placed for observers in the northern hemisphere. It will pass almost directly over the North Pole, making it a circumpolar object visible all night long.”

[American Patriot]

“I’m old enough to remember the last ‘Comet of the Century’. It fizzled. Comets are notoriously unpredictable,” said Don Yeomans of NASA’s Near-Earth Object Program.

That would have been "Comet Kohoutek" and I remember it well

[American Patriot]

Expect to see comet in the sunset sky between March 12 and 13

Staff Report
Posted: 03/05/2013 08:30:57 AM PST


A celestial wanderer, who currently can only be seen in the southern hemisphere, should burst into naked-eye view in the northern hemisphere later this month.

NASA says Comet Pan-STARRS (C/2011 L4) is currently inside the orbit of Mercury, brightening as it plunges toward the sun.


Observers in the southern hemisphere say they can see Pan-STARRS with the unaided eye in the evening sunset sky.


Several important dates are approaching.


Today the comet makes its closest approach to Earth, followed on March 10th by its closest approach to the sun.


As Comet Pan-STARRS passes the sun, solar glare might make it difficult to see even as the nucleus vaporizes and brightens.


By March 12th and 13th, the comet will reappear in the sunset skies of the northern hemisphere not far from the crescent Moon.


The scientists suggest that the comet's brightness will peak near 2nd magnitude, similar to the stars of the Big Dipper.


For additional information check out NASA's video at http://www.youtube.com/watch?v=OZlenAvqLCI.