The Moon is taking a journey through time the next couple of nights. It’s crossing the constellation Taurus. It’ll pass close to several of the bull’s most prominent features, plus another visitor – the planet Jupiter.

Jupiter looks like a brilliant star well to the upper left of the Moon. The bull’s brightest stars, Aldebaran and Elnath, line up below and above Jupiter. And the Pleiades star cluster is close below the Moon.

These objects are at different distances from Earth, so we see them as they looked at different points in time. That’s because light travels at a limited speed. It’s a high speed – 670 million miles per hour. But cosmic distances are so vast that it takes a long time to cross them.

The Moon is our closest neighbor, so moonlight takes only about one and a third seconds to reach Earth.

Jupiter also is in our own solar system, so it’s quite close by astronomical standards. Right now, it takes about 45 minutes for its light to reach Earth.

The stars are much, much farther. Aldebaran is about 65 light-years away, so its light takes 65 years to reach us. Elnath is twice as far, so its light headed our way in the late 1800s.

And the Pleiades is farther still. Its hundreds of stars are at different distances. But the average is about 445 light-years. So the light you see from the Pleiades tonight began its journey in the 1500s.

More about the Moon and Jupiter tomorrow.

Script by Damond Benningfield