How to Build a Metal Detector. Building your own metal detector is fun and educational. While building a traditional metal detector may require a kit (or in depth knowledge of electrical circuits), you can create simpler versions with.
Happy Halloween from NASA! Active regions on the sun combined to look something like a jack-o-lantern’s face on Oct. The image was captured by NASA's Solar Dynamics Observatory, or SDO, which watches the sun at all times from its orbit in space.