Thursday, January 18, 2007

NASA Horizons

No, I'm not talking about the New Horizons satellite. I'm talking about a service that has been done by NASA (specifically JPL) since at least 1996. This is just called "Horizons" (no "new"). This is a service provided by JPL that provides information for several (thousand) Solar System objects, including Ephemeris(es?) and basic geologic information. Now, I'll show you how to use the Horizons service with ease (actually it's not very easy, but it's useful). This is done by an internet protocol called Telnet. Telnet basically allows you to get into other computers over the internet. Now, there have been a couple of stories about Telnet being highly insecure, but if you're only using it for the Horizons service, then I think it's pretty safe. If you use it for other, more private, matters, you might want to use ssh (I'll go over this once I learn more about it).

First, get Telnet. This is usually not needed for most computers. If you have Windows, you can either use the out-of-the-box Hyperterminal or get some fancy-schmancy program I have no clue about. I will give instructions via the Hyperterminal. If you have linux, as I do, your computer should already have Telnet, but disabled. See the documentation for your specific distribution to find out how to enable it. The next 3 steps will be for Windows users, linux users could skip down.

Second, open the Hyperterminal. If you have Windows XP, you go All Programs> Accessories> Communications> Hyperterminal. If you have a previous version of Windows, you go Programs> Accessories> Communications> Hyperterminal.

Third, name your connection. This is a rather free step. Just name it whatever you want and click next.

Fourth, set up your connection. Now, for Telnet, you do not use the COM1, or whatever item you see in the last drop-down box. You click on that box and change it to TCP/IP (Windsock). Now, for the address, you put in horizons.jpl.nasa.gov and for the port you put in 6775. Click next and you're connected. Hooray.

Linux users, your job in considerably easier. Just open up the terminal and type "telnet horizons.jpl.nasa.gov 6775". Now you're connected.

It's getting late. I'll show you how to use it later. Need sleep.

1 comment:

Larry said...

Why use the hyper terminal ? Just use the command line interface in Windows.



great tutorial though