As spring arrives, going outside to get a taste of the warming weather can give you a great opportunity to glance up at distant planets. The night sky of April and May will be full of sightings to keep you busy – every planet you can see with your naked eye will be up in the sky! 2009 is also the International Year of Astronomy (IYA) and the 400th anniversary of Galileo Galilei’s discoveries. Galileo wasn’t the person who invented the telescope, but in 1609 he was the first to realize he could point it at the sky and view the heavens – a good idea which forever transformed the way we view the universe. One of the main focal points of the IYA is to encourage more people to observe the skies, so use the following suggestions and participate!
Mercury is visible low in the sky as the sun sets, but only an unobstructed view of the northwest will give you a good sighting. The planet quickly follows the sun under the horizon since it is the closest planet to the sun, and it does not rise very high at night. Its rapid movement across the sky led the ancient Greeks to name the star Hermes, the messenger of the gods. When Roman civilization overwhelmed that of the Greeks, they renamed the planet Mercury, after their own rendition of the Greek god. If you are on the NEIU campus and you have your heart set on seeing it, you can always climb to the top level of the parking garage and look to the northwest to see it in darkening skies. Although all the planets and stars are moving in the sky, Mercury will noticeably be moving much, much faster. In fact, people who are unfamiliar with the planet often react to its quick movement across the sky and claim that it is a UFO!
Most of the planets this month can be observed only before the sun rises. If the idea of waking up in the early morning is not too daunting (or if you have been up all night finishing papers or studying for finals) you can get a very good observation of four planets – Mercury, Venus, Mars and Jupiter – about a half hour before the sun rises. You will need a clear line of sight of the eastern horizon to see them and a perfect place to do this would be the parks along Lake Michigan. Just make sure to be aware of the park hours!
If you didn’t have a chance to see Venus during February and March, you won’t be disappointed watching it in the early hours of the morning. The planet will be the brightest object in the morning sky, other than the moon and the sun, and will probably capture your attention immediately. In the pale colors of the rising sun, it’s probably not too hard to imagine why the ancient Greeks decided to name the planet after their goddess of love.
Jupiter is also visible in the early morning. Although Jupiter is the largest planet in our solar system, it will not appear to be the brightest in the sky. One of its best known features is the giant red spot, an enormous hurricane-like storm that has been raging for over 400 years! The storm could possibly have been going on for longer, but since it is not visible to the naked eye, it wasn’t discovered until Galileo pointed a telescope at the planet in 1609. Unlike Earth and the other terrestrial planets, Jupiter is made up primarily of hydrogen and helium, the same gases that make up stars like our sun. Due to this composition of gases and its large size, some astronomers have called it a “failed star.” Although the planet would need to be much larger to start its own nuclear reactions and become a star, Jupiter still gives off more heat than it receives from the sun.
Mars is another prominent early morning planet, which stands out with its bright red color. Mars is named after the god of war, apparently because the red color reminded the Romans of blood and rage. The planet isn’t really as violent as its namesake lets on. Out of all the planets in the solar system, Mars is the most Earth-like. It is the only planet that has an atmosphere that you could safely breathe (yet it is so thin that you could only breathe it in for a few seconds). It has also been hypothesized as being a likely candidate for hosting extra-terrestrial life. Not the kinds of aliens we see in movies, but with the presence of water, cold-loving bacteria could be lurking under the Martian soil.
If early morning astronomical adventures aren’t your thing, you can always catch a glimpse of Saturn, the furthest planet you can see with your naked eye. Look high in the southern sky. If you’re on the NEIU campus, look over the Science Building and P.E. Complex. Although there are some stars brighter than it, Saturn will be the brightest object in the constellation Leo, where it will be hanging out for the next month. If you happen to have a telescope at home, or even a good pair of binoculars, you can treat yourself to some of the best views of Saturn’s rings we’ll have all year! (It also doesn’t involve any of that early morning stuff.) When Galileo first saw them, he didn’t quite know what they were and called them “handles.” Even today, scientists aren’t entirely sure what they are. Some speculate that the rings may have been formed when a comet strayed too close to Saturn and was torn apart by the massive planet’s gravity.
You can continue watching the skies over the summer. Visit http://www.astrosociety.org/iya2009 to get some helpful articles, guides, and viewing suggestions.