Posts by 

David Callejas

April showers – almost – in Sweden

Rain that falls from a cloud but evaporates before reaching the ground is called virga.

Comet PANSTARRS near Andromeda galaxy

Look for Comet PANSTARRS in early April 2013 near the Andromeda Galaxy.

Video: What if wild animals ate fast food

Be forewarned: It's goofy.

Ice on the rocks

Small ice sculpture which formed over lake in Vänersborg, Sweden

Video: One year of the moon in 2.5 minutes

Take 2.5 minutes to watch this animation shows the phases of the moon, captured hourly, throughout the course of one whole year

Gang of chimps kills their alpha male

In a rare display of behavior, a group of four chimps recently took down their leader.

Time-lapse of San Francisco Bay sky, clouds and sea

Sit back, relax and enjoy nature's wonders.

Video: Harlem shake lab edition

Video of students at Northwestern University doing the Harlem Shake in lab.

Snowflakes on wood

One of the few upsides to the recent snow storms has been the beautiful snowflake images we have received through e-mail and Facebook.

Video: New ring discovered in Earth’s radiation belts

Observations from NASA’s Van Allen Probes reveal an isolated third ring in the outer radiation belt.