Starship Asterisk*

http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2 ... ;log=0#orb

Search for "2007 WD5"

Type name in all caps "2007 WD5"

Set Mars as "Center"

Set zoom to max.

Advance at 1 Day at a time >| or run movie at >>|

Enjoy.

...

A change of 1 in 75 it will actually hit, they say.

Amazing, they are estimating only a 1 in 75 chance of 2007 WD5 impact with Mars on Jan 30, 2008.

http://www.jpl.nasa.gov/news/news.cfm?release=2007-152
http://www.jpl.nasa.gov/multimedia/podc ... -20071221/

Didn't original reports on aphophis give an estimate of 1 in 37 prior to re-evaluation?

http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2007%20WD5&orb=1
I forwarded the date and found that in Sept of 2060 it looks like it will come pretty close to Earth! maybe Mars will influence it's orbit even if it doesn't hit. What are the chances that Mars may capture WD5 as a moon?
Orin

Orin;

What are the chances that Mars may capture WD5 as a moon?

In bed with and intimately copulating with "impossible".

Think of how many thrust maneuvers the shuttle makes to get into a circular orbit, and think of that trying to park around Mars in a circular orbit. It could possibly be captured into a very eliptical orbit, but again very slim chance.

orin stepanek wrote:What are the chances that Mars may capture WD5 as a moon?

The asteroid is moving to fast to become a moon.

Newton gave us M = RV²/G for orbits, so R = GM/V². With the asteroid moving at 13.5 km/s (relative to Mars), a circular orbit would be at 5.3 km around Mars-as-a-point-mass, which is within Mars' volume. So, not a chance.

What are the chances that Mars may capture WD5 as a moon?

In bed with and intimately copulating with "impossible".

I concur.
Then everyone should be asking how did Phobos obtain a very fast retrograde circular degrading orbit?

Isoef Shmuelovich Shklovskii had a mathematically calculated theory that Phobos was/is an artificial satellite. Shklovskii’s theory had been substantiated by the Mars Express (JPL) MRSC/SRC investigative teams conclusions that Phobos is out of predicted position.

1st Mars Express Conference Presentations

Case wrote:

orin stepanek wrote:What are the chances that Mars may capture WD5 as a moon?

The asteroid is moving to fast to become a moon.

Newton gave us M = RV²/G for orbits, so R = GM/V². With the asteroid moving at 13.5 km/s (relative to Mars), a circular orbit would be at 5.3 km around Mars-as-a-point-mass, which is within Mars' volume. So, not a chance.

Not a chance?

What about air braking?

What about a gravitational encounter that places it in the the right situation to be captured in a high velocity retrograde orbit on their next encounter?

Of course the chances are very slim but with the Marian proximity to the asteroid belt acquiring temporary moons is inevitable - it has already happened at least twice.

OK! I know the chances are slim but it's fun to speculate. If aWD5 ricochets off of Mars by grazing the surface that would slow it down considerably; or if it comes close enough, Mars could probably slingshot the asteroid into a new orbit. I'M ssure it would probably break up into smaller pieces though.
Orin

Dr. Skeptic wrote:

Case wrote: What about air braking?

What about a gravitational encounter that places it in the the right situation to be captured in a high velocity retrograde orbit on their next encounter?
...acquiring temporary moons is inevitable - it has already happened at least twice.

Highly unlikely...and Speculation ≠ Science

Dr. Skeptic wrote:Not a chance?
What about air braking?

Martian atmosphere pressure is less than 1% of what we have here on Earth. Not much drag to slow it down to, say, 1/10th of its current speed.

Dr. Skeptic wrote:What about a gravitational encounter that places it in the the right situation to be captured in a high velocity retrograde orbit on their next encounter?

The current estimated passing distance of 48,000 km is probably enough for a deviation in its path. Maybe so much that it will 'never' come this close to Mars' orbit again.
They're plotting an orbit based on only 1 month of positions, since discovery. Predictions on a next encounter seem meaningless with the uncertainty so high for the next 30 days.

Dr. Skeptic wrote:Of course the chances are very slim but with the Marian proximity to the asteroid belt acquiring temporary moons is inevitable - it has already happened at least twice.

Phobos and Deimos probably weren't moving so fast. They are currently in the order of 2 km/s and 1 km/s, I don't think they were once approaching Mars at 15 km/s.

FieryIce wrote:
Highly unlikely...and Speculation ≠ Science

I've never written this before, but LOL!

FieryIce being scornful about 'speculation does not equal science'!
See FI on Phobos=artificial sattelite.

Happy Christmas!
John

JohnD
When will you learn to read? That is not FieryIce's signature, it is Dr. Skeptic's about the speculation = science with the slash in it, LOL back at yah.

Bet yah have a great X-Mass , , , ,, ,

Dr. Skeptic wrote:
Not a chance?
What about air braking?

Martian atmosphere pressure is less than 1% of what we have here on Earth. Not much drag to slow it down to, say, 1/10th of its current speed.

Other than flybys, air braking of one sort or another has been used by NASA on every Marian mission. The braking % would be dependent on the asteroid's angle of encroachment to the Marian atmosphere.

I forwarded the date and found that in Sept of 2060 it looks like it will come pretty close to Earth! maybe Mars will influence it's orbit even if it doesn't hit. What are the chances that Mars may capture WD5 as a moon?

Hmmm... I'm thinking if we can't even tell if it's going to hit Mars, we can't possibly know what it could do by 2060.

Possibilities:

1. It hits Mars, so it most certainly won't hit us.
2. It misses Mars by an unknown amount, which slingshots it off in some direction... ?

-Noel

3. It is "tidally" disrupted and makes another "crater chain".

FOCLMAO

FieryIce wrote:

What are the chances that Mars may capture WD5 as a moon?

In bed with and intimately copulating with "impossible".

I concur.
Then everyone should be asking how did Phobos obtain a very fast retrograde circular degrading orbit?

Isoef Shmuelovich Shklovskii had a mathematically calculated theory that Phobos was/is an artificial satellite. Shklovskii’s theory had been substantiated by the Mars Express (JPL) MRSC/SRC investigative teams conclusions that Phobos is out of predicted position.

1st Mars Express Conference Presentations

Phobos needn't have had as much initial velocity as 2007 WD5. Also, it is possible for multiple grativational and perhaps atmospheric interactions over millions of years to gradually slow an object down into orbit. However, the circularity of the orbit and inclination with Mars' equator suggests rather that they were formed by an extremely ancient impact with a large asteroid, similar to the leading theory for the formation of the earth's moon. If the Russians ever launch their planned Phobos lander, it may help answer that question.

You've already brought up the Mars Express investigations of Phobos. This is a combination of measurement error and tidal accelerations. Shklovskii's idea that it was artificial was based on the assumption that that the position error was solely the result of atmospheric drag, which would have required a density possible only if it were a thin shell. However, the ESA also measured the effect of Phobos' gravity on Mars Express, and used this to refine their density estimates, which place it at approximately 1.9 g/cm^3. This is completely consistent low density rock.

--

Anyhow, I got off track. I dropped by to note that astronomers found the object in some older photos and used those to refine the orbit a little bit. The odds that it will hit Mars are now placed at 3.9% (~1/25), pending further observations, which are due pretty quickly. Apparently it's so dim that just having a cresent moon lighting up the atmosphere makes it hard for all but the largest earth-based scopes to spot.

Also, it is possible for multiple grativational and perhaps atmospheric interactions over millions of years to gradually slow an object down into orbit.

uh huh, , , , "multiple grativational and perhaps atmospheric interactions"

This is a combination of measurement error and tidal accelerations.

and I thought it was gravity doing these things, , ,

Happy New Year everyone.