A Cloud Travelling to Mars
from Gerhard Holtkamp,
05. November 2009, 22:51
You might think that a story of a cloud which travels from Earth to Mars might come straight out of the Arabian Nights or similar tales. But read this report first...
At around 21:15 Central European Summer Time on Sunday 18-OCT-2009 people in Europe looking up into the sky could see two clouds moving very quickly on distinctly different trajectories. It was immediately clear that these were no ordinary clouds. They seemed to be illuminated even though the Sun was already deep below the horizon. The leading cloud even got brighter very suddenly.
Most people who observed this event were quite puzzled as to the origin of those clouds. Was it UFO's or maybe a secret military experiment? The second explanation came slighty closer to the truth.
Three hours earlier an Atlas-Centaur rocket had lifted off from Vandenberg AFB, California, with the DMSP F18 military weather satellite on board. The orbits of those satellites are officially kept secret but are known anyway due to amateur observers. But the satellite as such is not secret and the detailed launch timeline with all the planned activities were put on the Internet in advance.
This allowed Ted Molczan, the coordinator of the SeeSat visual satellite observer's group to come up with preliminary orbit elements not just for the satellite but also for the Centaur upper stage so that observers would be able to look for those objects. While the weather satellite would appear as a weak star travelling on a typical polar orbit of some 840 km altitude it was the Centaur which would perform some rather unsual maneuvers.
Normally after a satellite has been placed into a low orbit the associated upper stage would make a controlled deorbit maneuver to reenter the atmosphere (preferably over some remote ocean area). This avoids unnecessary space debris. But this time something very different was attempted: The Centaur had so much fuel left that it could leave the Earth altogether and enter an independent orbit around the Sun.
Fortuitiously this Earth escape maneuver took place over Europe so observers there had prime seats to look at it. Already one hour after launch did I get my first chance to see the Centaur and the satellite which was closely following. Through binoculars strange concentric halos surrounding the Centaur showed up. These were due to an experiment done after the satellite had separated and which was connected to tests about methods of long-term storage of propellants in space.
But it was two hours later on its next orbit that the real show started. I had expected to see a single could tracing the actual maneuver. But just as I spotted an elongated cloud near the predicted position of the weather satellite a second bright cloud appeared some 30 degrees away close to the predicted escape orbit position.
A more careful look showed the Centaur as a bright "star" surrounded by "puffs of smoke" and moving across the sky. I followed it for a few minutes and took some pictures two of which are shown here.
The explanation of what had happened goes like this: The Centaur uses liquid hydrogen and oxygen which produce clear water vapor. So the actual burn doesn't leave a visible cloud. But just before and after the burn some attitude maneuvers have to be done which use hydrazine. This and some extra venting connected with the special tests produced the visible clouds. So those clouds traced the orbits before and after the maneuver.
Although my pictures were taken with a wide angle lens and the timing was only accurate to about one second it was possible to use them for a rough orbit determination of the Centaur. Amazingly it turned out that the Centaur would pass close to the planet Mars in February/March next year.
Using accurate tracking data which I somehow got hold of I found that on 21-FEB-2010 the Centaur would pass Mars at a distance of about 6 Million km. As far as astronomical distances are concerned this is quite close. Luckily it doesn't hit Mars as this would have caused the wrath of planetary scientists. For the moment any spacecraft to reach the surface of Mars must be properly sterilized so as not to interfere with future research into life (or former life) on Mars.
But some of the molecules of the cloud I observerd might be on a collision course with the Red Planet. An extra 1 km/sec almost perpendicular to the trajectory of the Centaur would have placed objects on such a path. I think this is within the range of dispersion of molecules of that cloud.
So I keep telling myself (whether true or not) that I actually saw a cloud (part of) which travels from Earth to Mars!
At around 21:15 Central European Summer Time on Sunday 18-OCT-2009 people in Europe looking up into the sky could see two clouds moving very quickly on distinctly different trajectories. It was immediately clear that these were no ordinary clouds. They seemed to be illuminated even though the Sun was already deep below the horizon. The leading cloud even got brighter very suddenly.
Most people who observed this event were quite puzzled as to the origin of those clouds. Was it UFO's or maybe a secret military experiment? The second explanation came slighty closer to the truth.
Three hours earlier an Atlas-Centaur rocket had lifted off from Vandenberg AFB, California, with the DMSP F18 military weather satellite on board. The orbits of those satellites are officially kept secret but are known anyway due to amateur observers. But the satellite as such is not secret and the detailed launch timeline with all the planned activities were put on the Internet in advance.
This allowed Ted Molczan, the coordinator of the SeeSat visual satellite observer's group to come up with preliminary orbit elements not just for the satellite but also for the Centaur upper stage so that observers would be able to look for those objects. While the weather satellite would appear as a weak star travelling on a typical polar orbit of some 840 km altitude it was the Centaur which would perform some rather unsual maneuvers.
Normally after a satellite has been placed into a low orbit the associated upper stage would make a controlled deorbit maneuver to reenter the atmosphere (preferably over some remote ocean area). This avoids unnecessary space debris. But this time something very different was attempted: The Centaur had so much fuel left that it could leave the Earth altogether and enter an independent orbit around the Sun.
Fortuitiously this Earth escape maneuver took place over Europe so observers there had prime seats to look at it. Already one hour after launch did I get my first chance to see the Centaur and the satellite which was closely following. Through binoculars strange concentric halos surrounding the Centaur showed up. These were due to an experiment done after the satellite had separated and which was connected to tests about methods of long-term storage of propellants in space.
But it was two hours later on its next orbit that the real show started. I had expected to see a single could tracing the actual maneuver. But just as I spotted an elongated cloud near the predicted position of the weather satellite a second bright cloud appeared some 30 degrees away close to the predicted escape orbit position.
A more careful look showed the Centaur as a bright "star" surrounded by "puffs of smoke" and moving across the sky. I followed it for a few minutes and took some pictures two of which are shown here.
The explanation of what had happened goes like this: The Centaur uses liquid hydrogen and oxygen which produce clear water vapor. So the actual burn doesn't leave a visible cloud. But just before and after the burn some attitude maneuvers have to be done which use hydrazine. This and some extra venting connected with the special tests produced the visible clouds. So those clouds traced the orbits before and after the maneuver.
Although my pictures were taken with a wide angle lens and the timing was only accurate to about one second it was possible to use them for a rough orbit determination of the Centaur. Amazingly it turned out that the Centaur would pass close to the planet Mars in February/March next year.
Using accurate tracking data which I somehow got hold of I found that on 21-FEB-2010 the Centaur would pass Mars at a distance of about 6 Million km. As far as astronomical distances are concerned this is quite close. Luckily it doesn't hit Mars as this would have caused the wrath of planetary scientists. For the moment any spacecraft to reach the surface of Mars must be properly sterilized so as not to interfere with future research into life (or former life) on Mars.
But some of the molecules of the cloud I observerd might be on a collision course with the Red Planet. An extra 1 km/sec almost perpendicular to the trajectory of the Centaur would have placed objects on such a path. I think this is within the range of dispersion of molecules of that cloud.
So I keep telling myself (whether true or not) that I actually saw a cloud (part of) which travels from Earth to Mars!
Thanks for sharing your impressions and images, Gerhard.
I missed the event, partly because - you won't believe this - there is this friend and co-blogger who lives nearby, who knew about this event and who didn't tell me about it beforehand... :-)
As for the cloud, or parts of it, travelling to Mars, I would say that there is a high likelihood that some of it may arrive at Mars, and perhaps even in the not-too-distant future.
All gaseous matter carried out of our atmosphere or created beyond it, such as this cloud of propellant, is subject to solar radiation pressure and solar wind. If it is already on an escape trajectory, it is almost certain to be carried out further away from the Sun, getting more and more dispersed and diluted all along the way.
Some of it is likely to end up on Mars. In fact, scientists now think that the Earth and other planets are not completely separated from each other, and that they exchange material on a regular basis.
We know about asteroids from Mars that have been found on Earth, but it is likely that dust particles from the Earth, even those bearing organic material or inactive biots, can in principle find their way to Mars or other celestial bodies.
It is of course easier to fly out from the Sun, especially min ute particles with a high surface to mass ratio then get a free ride on the solar wind. The mass exchange inwards is les sprobably and typically involves extreme heating at departure and arrival.
This kiind of research should be seen in the context of recent discoveries of extremophile life forms on Earth. It is a fascinating now facet of the perennial topic of how life came to Earth and whether it can be found on other planets - arguably the greatest scientific question of all.