“The breathtaking magnificence of our natural world inspires us to praise God with wonder and appreciation. Therefore,… the Sages ordained blessings over various natural phenomena.

The blessing should preferably be said while standing. Viewing a phenomenon on film or broadcast is not the ‘real thing’ and does not justify a blessing.  However, a bracha is said when viewing with the aid of a telescope…”

There are specific blessings to be recited upon encountering:

• mountains
• deserts
• thunder and lightning
• astronomical phenomena
• earthquakes and fierce winds
• natural bodies of water
• rainbows
• animals and trees
• strange-looking people
• friends and relatives
• Jewish multitudes
• great leaders
• outstanding Torah scholars
• places of miracles
• destruction and restoration

See AISH.COM for specific details.