The more the sky stays the same, the more it changes
Thursday, January 5, 2012
There is always something about a new year. Almost like we have been given a clean sheet of paper so we can begin writing anew the things and events of our lives.
One thing we can say for the sky though, it is always there and it always looks the same.
The truth, however, is the sky is changing. The stars, galaxies, star clusters, in fact all astronomical objects are moving. Some away from us, some toward us, and some just passing by.
But with space being so large we, as humans, cannot see such change. We are talking about thousands of years here before change will be noticed, and the average life span of the average human is between 70 and 80 years.
The celestial objects are also traveling at, please pardon the pun, astronomical speeds but space is so large the movements are almost undetectable.
With the onset of winter, that means our old friend, Orion, the Hunter, is back in the sky. Orion is hard to miss, with the large hourglass shape with the distinctive three-star belt and the three stars below making up his sword.
We have discussed before that the middle star of the sword is not a star at all, it is a huge nebula of gas and dust and brand new stars called M-42, the Great Orion Nebula.
Of course, if Orion is there, that means the brightest star in the night sky, Sirius, is not far behind.
Be outside at about 8 p.m. local time and look to the southeast directly below Orion for a very bright star that will be sparkling like no other star. This is Sirius, the so-called "Dog Star" because it marks the eye of the big dog constellation, Canis Major.
Another plus for observing is that Sirius will be sparkling in color -- usually blue, white and red can be seen in the twinkle. If you want to intensify the effect, look at Sirius using a pair of binoculars. It will knock your socks.
Yesterday, Jan. 4, marks the day when Earth is at its closest to the sun for the entire year.
It may not feel like it, but remember our previous discussions where we discovered that the 23 and one-half degree tilt of Earth on its axis leans the northern hemisphere away from the sun thus giving us less direct, and warmer, sunlight.
Next week we will be able to use the bright planet, Venus, as a help in locating the dimmer outer gas giant planet, Neptune.
Starting on Thursday, Jan. 12, and continuing until Monday, Jan. 17 get your binoculars or that new telescope you received for Christmas and be outside at about 6 p.m. local time and locate bright Venus.
Look above and right of Venus at about the 1 o'clock position for the blueish color of Neptune.
It will be the object that is not twinkling. Remember, stars twinkle, planets don't. Watch each evening as Venus changes places in reference to Neptune, passing higher on the left side of Neptune each night. Both will be well within the same binocular field of view.
On Feb. 9, we will use Venus to locate another outer gas giant planet, Uranus. More about that later.
SKY WATCH:
Full moon, Monday, Jan. 9. The five visible planets are still making a showing for our observing pleasure. Venus and Jupiter in the evening sky and Mercury, Saturn, and Mars are holding forth in the early morning.
NEXT WEEK:
More astronomical blathering.