Venus crosses the Sun

Venus crosses the Sun

Astronomers love eclipses. And this has been a great year for them!


Never look directly at the Sun, even for a second! It will damage your eyesight forever!

To view a solar eclipse, use special solar viewing glasses. Get them from a camera store or online. Welding goggles will also work.


An eclipse happens when one object in space gets right in front of another object in space. Seeing that happen is awesome! And it is a chance to learn more about one or both of the objects.

Depending on what gets in front of what, we have different names for the eclipse.

Drawing of solar eclipse lineup. Sun, Moon and Earth line up, with the Moon in the middle.

When the Moon passes between us and the Sun, we call it a solar eclipse. It is the Sun that is being "eclipsed" (meaning hidden or blocked from sight).

To form an eclipse, the two objects and the observer must be located along a straight line.

Cartoon drawing of lunar eclipse lineup. Sun, Earth and Moon line up, with Earth in the middle.

When Earth passes right between the Sun and the Moon, we get a lunar eclipse.

These are the most notable eclipses we see on Earth. During a solar eclipse, daylight gets dimmer for a few minutes, then returns to normal. During a lunar eclipse, the Moon may look like an orange ball. We can still see it because it reflects some sunlight that has grazed Earth's atmosphere, becoming reddened and scattered by the atmosphere as if at sunset.

There is one other very rare eclipse that we can also see happening before our very SHIELDED eyes. That one is called a "Venus transit." Venus orbits closer to the Sun than Earth does. Sometimes Venus passes between Earth and the Sun. When things are lined up just right, we can see Venus as a small black dot moving across the face of the Sun.

How often can we see a Venus transit?

The answer is—not often! If you are more than 8 years old, you have been very lucky, because there have already been two Venus transits during your life. One occurred June 5 and 6, 2012. The previous one occurred in June 2004. Drawing shows the track of Venus during the 2004 and 2012 transits. But after 2012, the next one will not occur until 2117! You will have wait until way past your 100th birthday to see the next one. Want to know why?

Since the invention of the telescope, Venus transits have occurred in:

  • 1631 (not witnessed) & 1639
  • 1761 & 1769
  • 1874 & 1882
  • 2004 & 2012

Watch this video of the June 5, 2012, Venus transit as seen by the NOAA GOES-15 Solar X-Ray Imager.

Click here to see video of 2012 Venus transit.

Awesome, huh?!

article last updated August 17, 2012
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