Maybe you can use a sms utility to send a message from your observatory : smstools3.kekekasvi.com
I use it as a alarm if the temperature in the server hall gets too high or there is a power failure, I can also send a sms to a server and ask it so send back some status information to me.
Of course you need a USBstick GSM modem and a sim card but it can be worth it.