In a rare star-gazing event not to be seen for another 100 years, astronomy enthusiasts will get to catch a glimpse at a happening known as the transit of Venus.
Venus will be moving between Earth and the sun, allowing for spectators to actually see the planet's dark contrast against the brightness of the sun, "producing a silhouette that no one alive today will likely see again," according to NASA. There was also a transit of Venus in 2004, but the next one won't be until the year 2117. It's also an important event for NASA because monitoring the motion of Venus will help make sure instruments and telescopes are accurately adjusted
Curious on-lookers on seven continents and some areas of Antarctica will be able to catch a glimpse of the historic event. In the United States, we will be able to see it happen at sunset Tuesday night.
1. Do not look directly at the sun! They really mean it. Even though the silhouette of Venus will be visible against the sun's face, it covers far too little of the blinding glare to make it safe to look at. NASA recommends using a projection technique or solar filter, like a #14 welder's glass, instead. You could also get in touch with your local astronomy club to see what they have set up for the event.
2. Build a "pinhole camera." This is an easy way to safely observe the sun and all you need are two sheets of white paper and a pin. Use the pin to make a hole in the center of both sheets of paper. The raise the paper to the sky towards the sun. Find the sun's image through the hole and adjust the other piece of paper back and forth until you find a clear image of the sun.
3. Use a pair of binoculars to project a magnified view of the sun through onto a white surface. Click here for directions on how to do it.
4. Check viewing times for your area. Depending on where you live, the transit of Venus will be visible at different times. Sunset is at 8:24 p.m. in NYC, 8:17 p.m. in Boston and 8:26 p.m. in Philadelphia. Click here for an interactive map that offers more details on exactly what time to watch depending on your location.
5. Attend a viewing event. NASA has compiled a list of events and festivals around that world offered by science clubs, astronomy museums, and star-gazing enthusiasts, that offer viewing equipment set up for your convenience. Check the map to find an event in your area.