Orbiters Study Effect of Giant Comet-Caused Meteor Shower On Mars

An anonymous reader writes According to observations made by NASA and ESA orbiters, the extremely close flyby of comet C/2013 A1 Siding Spring to Mars was accompanied by a meteor shower larger than any seen on Earth. NASA said that dust from Comet Siding Spring vaporized high up in the Martian atmosphere, producing "an impressive meteor shower." An observer on Mars surface might have seen thousands of shooting stars per hour. "This historic event allowed us to observe the details of this fast-moving Oort Cloud comet in a way never before possible using our existing Mars missions," Jim Green, director of NASA's Planetary Science Division at the agency's Headquarters in Washington, said in the statement.

Comments

Effects on Martian atmosphere

[TWX]

I'm curious as to what effects, if any, were measurable in the Martian atmosphere. Science fiction authors have speculated on the possibility of continually crashing comets into Mars as a way of increasing the water content and thickening the atmosphere of the planet. In some ways it's far-fetched, but on the other hand it's probably the cheapest way to add water to Mars..

Re:Effects on Martian atmosphere

[wierd_w]

MAVEN detected large spectrometry spikes for several metallic elements, and several non-metallic ones as well, which persisted for hours after the comet passed by.

Hang on, I will dig up a source.

http://www.universetoday.com/1...

Bam. There you go.

Re:Effects on Martian atmosphere

[wierd_w]

Not with an 80 million year transit period it isn't.

A series of radiative heaters stuck to the surface with a computer control system would do the trick. (assuming some long lived power source, like a suitably large RTG)

The real trick then is getting probes into the oort cloud and attaching them to the nearest candidate objects at a human-sensible timetable. Without FTL of some sort, or at the very least, a significant improvement in thruster technology, this is a non-starter.

kuiper belt objects on the other hand, could theoretically be harvested within human timetables, and asteroid belt objects most certainly could.

Stone type asteroids contain a significant amount of bound elemental hydrogen and oxygen. That makes them attractive candidates.

Re:Effects on Martian atmosphere

[wierd_w]

Enlighten me-- what feature of your professed "reality" did I miss?

Oort cloud objects are so far away, that it takes them literally millions of years for them to reach our part of the solar system after they get nudged from their orbits by passing stars perturbing their orbits.

Rather than rely on stellar interaction, a mission to purposefully send robot drones into the oort cloud is theoretically possible, but as I pointed out, would require either FTL or a radical improvement in thrust technology to accomplish on human timetables. It took 70 years for voyager to reach the heliopause, AFTER it was gravitationally accellerated by several gas giants. The voyager probe was pretty small too, in comparison to what would need to be sent to the oort cloud to commence a mission of the magnitude the OP suggests. Getting something that heavy out that far before it's mission creators die of old age is a pretty significant bump. That's why I covered that bit by saying it would require, at the very least, a radical improvement in thruster technology.

Once out there though, all it would take is slow, but constant thrust on an object to dislodge its orbit. There would be considerable time for these objects to pick up momentum from their inward plunge. Again, a radiative heater aimed at the surface of the comet at strategic points, controlled by a computer guidance system, would allow for the comet to be steered into the appropriate entry window for mars collision.

It would just take a very, very, very long time. Last I checked, "Very long time" != "Can't be done".

Then we come to the latter point I made-- objects in the asteroid belt between mars and jupiter. Objects in this area are much easier to get to, and could realistically be sent on collision courses with mars regularly with a fleet of automated vehicles. Ion thrusters are more than adequate for this latter kind of planetary engineering. Objects in the asteroid belt range from dust particles to things the size of mountains, to those the size of small moons. You dont need nor want the collossally huge ones. You dont want to destroy the target planet with a massive collision, after all. Sending objects the size of dump trucks or so to mars using controlled, vectored ion engine thrust over long timetables of several years is perfectly plausible.

Since I am telling you how it COULD be done, and you are insisting that it cannot, "because orbital mechanics", the onus of proof is on you.

No, calling me a "Space nutter" or other ad-hominem does not absolve you of this obligation.

Re:Effects on Martian atmosphere

[wierd_w]

*Yawn*

The part where you invoke dozens of improbabilities and outright impossibilities?

And it's not a "professed" reality (nice religious term there), it IS reality.

Oh, so things like this simply can't ever work huh?

Nevermind that it is fully mathematically sound, and the only reason why it was never used was because of anti-nuke hysteria. No no-- your "reality" says things like this are simply not possible! (Since you seem to be so thick, I am using the scare quotes to point out that what you consider to be reality is a fiction of your own manufacture, which does not in any way hold with what is actually possible.)

"Since I am telling you how it COULD be done, and you are insisting that it cannot, "because orbital mechanics", the onus of proof is on you."

Nope, extraordinary claims require extraordinary proof. Waving sci-fi around while yelling about "could be"s is not good enough, sorry. That's a religion.

No one's going anywhere, there won't be any robotic mining missions to the Oort cloud, no Mars colonies, no weekend cottages on the Moon, no jungle resorts on Venus either.

Funny how Venus isn't part of the Space Nutter repertoire anymore, eh?

Where's your blind trust in technology getting better and impossible physics breakthroughs when it's about Venus?

Hmmm???

You mean, like this post I made last year?

Synthetic biology is closer than you realize sir.

Aramid plastic has a thermal decomposition temperature of 500c, which also happens to be the mean surface temperature of venus.

Aramid plastic

Venusian climate and atmospheric composition

There is a sufficiently high concentration of suitable sulfur compounds in the upper venusian atmosphere, where it is a nice balmly 70 degrees Fahrenheit, for sulfur-cycle microbes to live perfectly happy, carefree lives-- shitting out aramid plastic non-stop should they be engineered to do so. Given that that the feedstock used to produce aramid plastic is an amine group and a carboxyl-halide group, this is a perfectly reasonable material to biosynthesize. (Biogenic amines are a staple of most terrestrial lifeforms in fact, and there is sufficient carbon dioxide and hard sulfuric acid vapor in the venusian atmosphere to allow sulfur cycle energy production, with carboxylic acid biproducts of celluar activity. Combined, it is not hard at all to imagine aramid being biologically synthesized, and falling to the venusian surface as the microbes die. This would result in accretion of a carbon-rich material that is thermo-stable at venus's existing surface temperature, which would puncture the greenouse effect of the planet.)

But of course, I TOTALLY never made posts about that in the past-- No sir-- that would fly in the face of your "reality", where "Space nutters" dont have interesting proposals about venus at all!

We couldnt let the actual reality that this is not true intrude at all. No sir.

Re:Effects on Martian atmosphere

[wierd_w]

Issues with your calculation:

1) it's cherry picked. The premise stated by the calculation is that the object is in or near earth's orbital vicinity. To avoid being drawn into the sun, it will require a considerable inertial energy statistic. Items in the very deep solar system? Not so much, since gravity falls off with the inverse cube of distance between the center of mass of the two gravitating bodies.

That means that the object the OP referenced, an oort cloud object, need not have the orbital energy that the object referenced by your sample calculation requires to avoid falling into the sun.

EPIC FAIL.

2) Due to the rather profound difference in gravitational attraction with the sun at these two orbits, and the very large travel distance that the oort cloud object has before it reaches the inner solar system, (and the "free" velocity change the object will get as the gravitational influence of the sun increases as this distance is reduced), the total energy required to de-orbit an oort cloud object will be considerably less than that needed to de-orbit an object of identical mass in the inner solar system.

EPIC FAIL AGAIN.

Now, if you would be so kind, show me an orbital computation that isnt a fucking orange when we are discussing apples, and I will happily relent.

Otherwise, quit making false equivalence based arguments.

Re:Effects on Martian atmosphere

[wierd_w]

Using kepler's third law, an object weighing 1 gram, at a distance of 100,000 AU (the oort cloud), orbiting a star with 1 solar mass, will have an orbital period of 316174 CENTURIES. (Or, 9.97786e+14 seconds)

We then need to know the total distance of the orbit, in order to determine the orbital velocity of this object.

Best current estimates for the location of the oort cloud is between 5,000 AU and 100,000 AU. We can use these as the semiminor and semimajor axes of the orbital elipse. This gives us a circumference of the orbital elipse of 222421.65 AU.

One AU is equal to 149,597,870,700 meters. This means the circumference of the orbit is 33,274,027,659,230,655 meters.

We can now use the page you linked to to get the kinetic energy of this 1g object at that distance, after we get its orbital velocity.

33274027659230655 meters / 9.97786e+14 seconds == 33.347859820874070191403767942224 meters/second

The page you cited states that the formula for determining kinetic energy is as follows:

E = (1/2) m v^2

We will simplify a bit, and say the 1 gram object is moving at 33.35 meters per second. Let's fill in some blanks.

E = (1/2)*(.001)*(33.35)^2

Simplifies to:

E = (.5) * (.001) * (1112.2225)

Which works out to
0.55611125 Joules

As you can see, this is RADICALLY different from the 450000 joules the same 1g object has in earth orbit!

APPLES are NOT ORANGES.

Re:Effects on Martian atmosphere

[wierd_w]

The indian mars orbiter, a vehicle with a lander module, and designed for interplanetary flight, cost less to manufacture and launch than the sandra bullock movie Gravity.

Source
http://money.cnn.com/2014/09/2...

So, there's the cost of a suitable vehicle. About 74 million dollars.

Then we have the designer microbe end. Most designer microbes are intended for biofuel production, using fully synthetic biological pathways, designed by humans.
http://www.hindawi.com/journal...

Other sources of interest are the biodegredation of toxic agents:
http://www.nature.com/nchembio...

And of course, Plastics.
http://garj.org/garjm/pdf/2013...

Feel free to order some of those researcher's samples!

Perhaps you would want some that are sporting a fully 100% human created genome?
http://www.jcvi.org/cms/press/...

Microbes are tenacious things. Once cultured in the lab, and loaded into a delivery system, sending them to venus would cost about 80 million dollars.

Cost of R&D of modifying a suitable sulfur cycle microbe for venusian atmospheric conditions would cost around 100 to 200 million.

So, for around the 300 million dollar mark, we could be initiating the end of the hellish environment on venus-- OR-- we could pay for a few military airplanes.

You are a delusional moron.