Discussion in 'UFOs & Sightings' started by nivek, Nov 27, 2017.
This would be great.....just getting closer to it would be helpful as well.
We could catch these things and mine them in Earth orbit how cool is that.
One more time:
Space is mostly empty. There isn't much debris outside of the orbital plane until you get to the Oort cloud.
Between stars (actually outside the shock boundary of the individual stars) there just isn't much there.
I welcome evidence to the contrary and opposing views.
Well, most of what we want to mine is in the asteroid belt.
The real challenge is going to the Kuiper belt or Oort cloud to get comets for Mars.
Why do they want comets for Mars ?
Easiest way to get an atmosphere is methane and ice comets. That gets you nitrogen and oxygen.
Takes a lot or really large ones.
Just the atmosphere takes a 7 kilometer diameter comet.
Wouldn't want to be around when they dump them on there.
Well, it doesn't have to be that bad. If the comet comes from behind the in orbit and you fire engines to slow it down you could have it land at less than escape velocity. For Mars escape velocity is 5 kps. That is twice as fast as the US railgun, but just snailing by interstellar standards.
The theory behind comets and asteroids is to smack the sh*t out of the planet.
That isn't your goal. And less than 5 kps is just going to leave a small dent.
Isn't it all supposed to be about using the water in the comet to kick start the evolution process ?
I think if they are planning on doing this it won't be for study alone. In this case it might be interesting for study.....as those who wholeheartedly think this is space ship will never believe it unless it could be captured. It would no doubt be pock marked by space dust and micro-asteroids floating around between solar systems.
Earths atmosphere is 5.1480×1018 kilograms or 5148 teratonnes
Mars atmosphere is 25 x 1016 kilograms or 2.5 teratonnes. The pressure is 0.6% of earth's.
2.5 / 0.006 = 416 teratons
You need about 400 tt of gas to get the atmosphere up to earth standard atmospheric pressure.
We would want Ammonia comets (probably said something else), at cryogenic temperatures ammonia is about as a dense as water.
Need to correct some previous math. To get 1% of 400 teratonnes you would need an 12.5 kilometer ammonia comet.
The ammonia would disassociate and form nitrogen and hydrogen.
The ammonia comet would have to come from the Kuiper belt or Oort cloud and you could just park it in low Mars orbit and let it evaporate.
Since the nitrogen is more necessary than water, the goal would be to get the nitrogen level up and let the water level be whatever ice melts from the comet.
So whats going to regenerate the atmosphere with no trees and plant life ? Would you have to dump a new comet on Mars every now and then to keep the atmosphere going ?
Interstellar Object Oumuamua Could Be a Comet in Disguise
When astronomers first spotted the oblong, tumbling interstellar object 'Oumuamua passing through the solar system in October, they were surprised — not only did it come from outside the solar system, according to its trajectory, it seemed to be an asteroid, rather than the comet researchers thought was more likely for an interstellar visitor.
However, a new paper suggests 'Oumuamua may be made of ice, like a comet, just disguised with a protective crust.
According to professor Alan Fitzsimmons from the Queen's University Belfast, Northern Ireland, there is much more "icy stuff than rocky stuff" in the solar system, making it more likely for emissaries from other systems to also be icy, if other solar systems evolved in the same way.
"We know that our solar system has ejected many more icy bodies than rocky bodies," Fitzsimmons, lead author of the paper published today (Dec. 18) in the journal Nature Astronomy, told Space.com.
As the solar system formed, planets made of gas and ice near the outer edges of the solar system ejected trillions of objects, Fitzsimmons said. In addition, the mass of small icy bodies at the outermost reaches of the solar system, known as the Oort cloud, has lost objects over billions of years due to gravitational disruption from other stars. It was therefore logical for astronomers to expect that the first interstellar visitor they would see should be a comet.
"Given that this object passed relatively close to our sun as it was travelling through our solar system, one would expect any ices on the surface to basically be heated and it should behave like a comet," Fitzsimmons said. "We should see gas streaming off the surface, we should see dust particles being ejected in the cometary atmosphere, perhaps even a tail."
But astronomers observing 'Oumuamua with their telescopes have seen no signs of such a behavior. They concluded that the object must be rocky in nature — an asteroid. However, when Fitzsimmons and his colleagues examined data on the surface of the object more closely, they found it doesn't look like a typical asteroid either.
"We didn't see any signs of typical spectroscopic signatures that you would expect from the minerals on the surface of an asteroid we see in our solar system," Fitzsimmons said. "It rather seems to resemble the [icy] objects that are there in the outer solar system. That kind of got our head scratching. If the object had, originally at least, ice in it, what's happened to it?"
Fitzsimmons and his colleagues looked at older studies and laboratory experiments that tried to find out what happens to icy bodies, such as comets, that are exposed for a long time to energetic particles and cosmic rays. These studies suggest that the ice from the surface layers of such bodies evaporates because of the cosmic environment.
"What gets left transforms itself into a relatively rigid and desiccated surface held together by carbon compounds, which at the same time gives a sort of a reddish, pinkish color," Fitzsimmons said. "And that's what we saw in our spectra."
The astronomers ran a series of computer experiments to model the behavior of the now icy 'Oumuamua. They found that if the object's crust was only 20 inches (50 centimeters) thick, it would protect the ice at the object's core from the heat of the sun, thus preventing it from displaying the telltale signs of gas and dust leaving a comet.
In a separate paper that will be published in the Astrophysical Journal Letters later this month, Fitzsimmons' colleague Michele Bannister, also from Queen's University, looked at further properties of 'Oumuamua in the near-infrared spectrum and compared the data with those on similar objects in the outer solar system. She found staggering similarities.
"We've discovered that this is a planetesimal with a well-baked crust that looks a lot like the tiniest worlds in the outer regions of our solar system," Bannister said in a statement. "It has a greyish/red surface and is highly elongated, probably about the size and shape of the Gherkin skyscraper in London."
While 'Oumuamua's arrival has been one of the most significant astronomical events of 2017, Fitzsimmons and Bannister expect that such occurrences will become rather common in the future. Similar objects likely make it into the solar system fairly regularly, the astronomers said, but they are usually too faint to spot with current telescopes. As telescope technology advances, Fitzsimmons said he expects that astronomers in the not so distant future will be able to study such interlopers perhaps every year.
"On the horizon we have a new telescope facility they are building at the moment called the Large Synoptic Survey Telescope in Chile," Fitzsimmons said.
"That's going to be an incredibly powerful survey machine. When that starts operating in the first half of the next decade, that will have a much better chance of detecting these objects in the solar system than the current facilities that we have."
Separate names with a comma.