What's this all about?
Light travelling in empty space is the fastest thing in the universe. It
travels at 186,000 miles per second!
The stars are so far away from
us that their light still takes a long time to reach Earth. One light
year is the distance light travels in a year: 5,878,499,812,499
miles. The closest star apart from the Sun is 4.2 light years away, so its
light takes 4.2 years to reach Earth.
Tell the Birthday Stars computer when you were born, and it will look for a
star that is your age in light years away from Earth. This means that the
light we're seeing from that star today actually left the star around when you
were born, and has taken your entire life to reach Earth.
From month to month you may see your birthday star changing. This is
because as you get older the light from more and more distant stars has had
the time to travel to Earth in during your life.
Please note: "Birthday Stars" does not work with Netscape 4. If you
are using Netscape 4, please consider upgrading to a more recent and
standards-compliant browser such as Netscape
the Joint Astronomy Centre, using some data from the Yale Bright Star Catalog and
the NStars project.
the Joint Astronomy Centre
the Gemini Observatory, using some data from the Yale Bright Star Catalog and
the NStars project. If you have any problems or questions, please email