A wide open space (It could be your backyard or a park.) Two Hula-Hoops (Alternatively, you could use two flat rocks or bricks that you can sit on.) A yardstick or meterstick (Use one that has clear ...

For the first time, astronomers have directly measured the distance to a spot clear across the galaxy. The established but challenging technique promises a new way to map the structure of the Milky ...

Astronomical units (AU), defined by the Sun-Earth distance, are used for measuring distances within solar systems. Light-years, representing the distance light travels in a year (approximately 6 ...

Parallax is the observed displacement of an object caused by the change of the observer's point of view. In astronomy, it is an irreplaceable tool for calculating distances of far away stars. When you ...

Let’s try a demonstration that we all enjoyed in elementary school. Close one eye, hold out your thumb at arm’s length, and align it with an object on the other side of the room. Without moving your ...

The universe is so vast that even the closest stars are light-years away. They are so distant that they were long thought to be fixed points in the velvet night. Since we can't yet travel to the stars ...

It isn't easy to measure the distance of stars. We can't travel to them, counting the miles as we go, nor can we simply say that brighter stars are closer and dimmer ones more distant. Instead, we ...

For the first time, astronomers have directly measured the distance to a spot clear across the galaxy. The established but challenging technique promises a new way to map the structure of the Milky ...