Celestia Forums

You'll have fun with it. I just dusted mine off. I got a new Canon Digital Rebel, and I want to connect it to my ETX-90 through the camera port. Gotta go buy the adapter tommorow. The Canon took some pretty nice star pictures last night just by itself without a telescope, but I can't wait to get it ...

Sorry, I meant km / hours, not seconds. That would have blown my car to Mexico. It still shook the car though. About as hard as if the car were parked and someone was pushing down on the bumper with their hands. Thanks for the math behind my question. I can rest easier knowing that the rover is not ...

I hope it starts transmitting data again soon. I'd hate to lose the rover this early in its mission. I have a question about the winds on Mars. I asked this on the Oribiter forum, but I'll ask it here too. This is probably a silly theory, but is it possible that a dust devil knocked the rover on its...

I own that telescope (ETX-90), and also a Celestron. A few months ago around the time of Mars' opposition, Costco had a large supply of Celestron GT114 telescopes for only $200. Check it out at your local Costco and see if they still have them. Then, a week after I bought it, it went on sale for $16...

You could run a simulation. Based on your question, I tried this in Gravity Simulator. I placed a planet inbetween Earth and Venus in a circular orbit, and another planet at 2 AUs from the Sun, just exterior to Mars' orbit, also in a circular orbit. After letting the simulation run for about 280,000...

Jack, thank you for the link. It's fun to play with stuff like that. You can also simulate it with GravitySimulator, a program I wrote, which is avaliable at GravitySimulator.com. This lets you do it in 3-D, so the star can pass from above or below. You can do further passages too that just knock th...

With so many objects in close proximity to the Sun, does anyone know of a formula to figure out what is the closest another star has ever passed to the Sun in the Sun's 5 billion year history? Maybe the answer would be in the form of "> 50% chance that another star has passed < 0.1 ly. I found a for...

Thanks, Jack I'm new to Celestia and not quite sure what to do with your add-on to see the trajectory. I'll goof with it tonight and figure it out. I'm trying to use my own program, GravitySimulator, to model Earth escapees which is why I'm wondering how many such things exist. I put 10 objects into...

Last year Apollo 12 rocket booster S-IVb was discovered in Earth orbit, having been captured after spending years in solar orbit. Does anyone know how many other man-made objects are orbiting the Sun as space junk, objects that were launched on escape trajectories or objects launched into Earth orbi...

Tony, What orbit simulation program are you using? Gravity Simulator www.gravitysimulator.com where d is the mean separation of m and M. How do you compute the mean separation of an elliptical orbit? is it (Semi-major axis + Semi-major axis) / 2, or is it a more complicated formula that takes into ...

I don't know the math to figure out your questions, but plugging this stuff into a simulator lets me answer most of your questions. Yes, they are located at opposite ends of a circular orbit, .5 AU from their center of mass. Here's 2 solar mass stars. The yellow star is locked to the center of the s...

I don't know what the theories are, but I have my own guesses. I think that our solar system is very lucky to still have its original configuration. I think the extra-solar systems discovered to date probably formed looking a lot more "normal" (us being normal) and then evolved into their current st...