by neufer » Sun Aug 30, 2015 4:13 pm
Chris Peterson wrote:John644 wrote:
I am curious to the question, if anyone has considered, using a comet, such as this one, as a vehicle to deliver deep space probes for exploration?
It's an interesting idea. But keep in mind that the challenge of getting from the Earth to another place in the Solar System isn't the distance traveled, but the energy required to match an orbit. The more eccentric a comet's orbit, the greater differential velocity it will exhibit with respect to Earth while it is at Earth's distance from the Sun. So the sort of body that would be desirable to use as a vehicle is also the sort that will be hard to land on while it is near the Earth.
Comets & asteroids might provide good spaceships
for humans to travel into space & return while providing them water, shelter, radiation protection and (most importantly) something to do to pass the time (e.g., skating & sleigh sailing). This is especially important for human travel
to inner space near the Sun.
https://en.wikipedia.org/wiki/%28137924%29_2000_BD19 wrote:
<<2000 BD
19 is [a ~1km diameter] asteroid with the smallest perihelion of any numbered asteroid (0.092 AU—38% of Mercury's orbital radius). With its high eccentricity, not only does 2000 BD19 get very close to the Sun, but it also travels relatively far away from it. It is one of a small group of Aten asteroids that is also a Mars grazer. Its orbital elements indicate that may be an extinct comet.
It is estimated that 2000 BD
19's surface temperature reaches ~920 K at perihelion, enough to melt lead and zinc, and nearly enough to melt aluminium. 2000 BD19 is considered a good candidate for measuring the effects of Albert Einstein's general theory of relativity because of how close it comes to the Sun.>>
https://en.wikipedia.org/wiki/Off_on_a_Comet wrote:
Off on a Comet (French: Hector Servadac) is an 1877 science fiction novel by Jules Verne.
<<The story starts with a comet called Gallia, that touches the Earth in its flight and collects a few small chunks of it. The disaster occurred on January 1 of the year 188x in the area around Gibraltar. On the territory that was carried away by the comet there remained a total of thirty-six people of French, English, Spanish and Russian nationality. These people did not realize at first what had happened, and considered the collision an earthquake. They first noticed weight loss: Captain Servadac's adjutant Ben Zoof to his amazement, jumped twelve meters high. Zoof with Servadac also soon noticed that the alternation of day and night is shortened to six hours, that east and west changed sides, and that water begins to boil at 66 degrees Celsius, from which they rightly deduced that atmosphere became thinner and pressure dropped. At the beginning of their stay in Gallia they noticed the Earth with the Moon, but thought it was an unknown planet. Other important information was obtained through their research expedition with a ship, which the comet also took. During the voyage they discovered a mountain chain blocking the sea, which they initially considered to be the Mediterranean Sea and then they found the island of Formentera (before the catastrophe a part of the Balearic Islands), where they found a French astronomer Palmyrin Rosette, who helped them to solve all the mysterious phenomena. They were all on the comet which was discovered by Rosette a year ago and predicted a collision course with Earth, but no one believed the astronomer, because a layer of thick fog at the time prevented astronomical observations in other places.
As found by a new research expedition, the circumference of Gallia was 2320 km.
Involuntary travelers through the Solar system did not have any hope for long-term colonization of their new world, because they were lacking arable land. They ate mainly the animals that were left on the land carried away by Gallia. One strange phenomenon, they met was that the sea on the comet did not freeze, even though the temperature dropped below the freezing point (theory that the stationary water level resists freezing level for longer than when a rippled by wind). Once a stone was thrown into the sea, the sea froze in a few moments. The ice was completely smooth and allowed skating and sleigh sailing.
Gallia got to an extreme point of its orbit and then began its return to Earth. In early November Rossete's refined calculations showed that there will be a new collision with the Earth, exactly two years after the first, again on January 1. Therefore, the idea appeared to leave the comet collision in a balloon. The proposal was approved and the castaways made a balloon out of the sails of their ship. In mid-December there was an earthquake, in which Gallia partially fell apart and lost a fragment, which probably killed all Englishmen in Ceuta and Gibraltar. When on January 1 there was again a contact between the atmospheres of Gallia and Earth, the space castaways left in the balloon and landed safely two kilometers from Mostaganem in Algeria.>>
[quote="Chris Peterson"][quote="John644"]
I am curious to the question, if anyone has considered, using a comet, such as this one, as a vehicle to deliver deep space probes for exploration?[/quote]
It's an interesting idea. But keep in mind that the challenge of getting from the Earth to another place in the Solar System isn't the distance traveled, but the energy required to match an orbit. The more eccentric a comet's orbit, the greater differential velocity it will exhibit with respect to Earth while it is at Earth's distance from the Sun. So the sort of body that would be desirable to use as a vehicle is also the sort that will be hard to land on while it is near the Earth.[/quote]
Comets & asteroids might provide good spaceships [b][u]for humans[/u][/b] to travel into space & return while providing them water, shelter, radiation protection and (most importantly) something to do to pass the time (e.g., skating & sleigh sailing). This is especially important for human travel [b][u]to inner space near the Sun[/u][/b].
[quote=" https://en.wikipedia.org/wiki/%28137924%29_2000_BD19"]
<<2000 BD[sub]19[/sub] is [a ~1km diameter] asteroid with the smallest perihelion of any numbered asteroid (0.092 AU—38% of Mercury's orbital radius). With its high eccentricity, not only does 2000 BD19 get very close to the Sun, but it also travels relatively far away from it. It is one of a small group of Aten asteroids that is also a Mars grazer. Its orbital elements indicate that may be an extinct comet.
It is estimated that 2000 BD[sub]19[/sub]'s surface temperature reaches ~920 K at perihelion, enough to melt lead and zinc, and nearly enough to melt aluminium. 2000 BD19 is considered a good candidate for measuring the effects of Albert Einstein's general theory of relativity because of how close it comes to the Sun.>>[/quote]
[list]. https://en.wikipedia.org/wiki/Comet_Encke[/list]
[quote=" https://en.wikipedia.org/wiki/Off_on_a_Comet"]
[float=right][img3=""]https://upload.wikimedia.org/wikipedia/commons/b/bc/%27Off_on_a_Comet%27_by_Paul_Philippoteaux_001.jpg[/img3][/float]
Off on a Comet (French: Hector Servadac) is an 1877 science fiction novel by Jules Verne.
<<The story starts with a comet called Gallia, that touches the Earth in its flight and collects a few small chunks of it. The disaster occurred on January 1 of the year 188x in the area around Gibraltar. On the territory that was carried away by the comet there remained a total of thirty-six people of French, English, Spanish and Russian nationality. These people did not realize at first what had happened, and considered the collision an earthquake. They first noticed weight loss: Captain Servadac's adjutant Ben Zoof to his amazement, jumped twelve meters high. Zoof with Servadac also soon noticed that the alternation of day and night is shortened to six hours, that east and west changed sides, and that water begins to boil at 66 degrees Celsius, from which they rightly deduced that atmosphere became thinner and pressure dropped. At the beginning of their stay in Gallia they noticed the Earth with the Moon, but thought it was an unknown planet. Other important information was obtained through their research expedition with a ship, which the comet also took. During the voyage they discovered a mountain chain blocking the sea, which they initially considered to be the Mediterranean Sea and then they found the island of Formentera (before the catastrophe a part of the Balearic Islands), where they found a French astronomer Palmyrin Rosette, who helped them to solve all the mysterious phenomena. They were all on the comet which was discovered by Rosette a year ago and predicted a collision course with Earth, but no one believed the astronomer, because a layer of thick fog at the time prevented astronomical observations in other places.
As found by a new research expedition, the circumference of Gallia was 2320 km.
Involuntary travelers through the Solar system did not have any hope for long-term colonization of their new world, because they were lacking arable land. They ate mainly the animals that were left on the land carried away by Gallia. One strange phenomenon, they met was that the sea on the comet did not freeze, even though the temperature dropped below the freezing point (theory that the stationary water level resists freezing level for longer than when a rippled by wind). Once a stone was thrown into the sea, the sea froze in a few moments. The ice was completely smooth and allowed skating and sleigh sailing.
Gallia got to an extreme point of its orbit and then began its return to Earth. In early November Rossete's refined calculations showed that there will be a new collision with the Earth, exactly two years after the first, again on January 1. Therefore, the idea appeared to leave the comet collision in a balloon. The proposal was approved and the castaways made a balloon out of the sails of their ship. In mid-December there was an earthquake, in which Gallia partially fell apart and lost a fragment, which probably killed all Englishmen in Ceuta and Gibraltar. When on January 1 there was again a contact between the atmospheres of Gallia and Earth, the space castaways left in the balloon and landed safely two kilometers from Mostaganem in Algeria.>>[/quote]