By David Ward
Standing outside on a peaceful star-studded winter night, it is impossible for us to comprehend the tremendous raw power of the stars. In the daytime we get a feel for the power of the sun. It is too bright to look at and it will burn our skin if we are not careful. Did you know that our sun produces and emits the energy of six trillion
Hiroshima-sized atomic bombs every second? Luckily, we are 93 million miles away!
Almost all the stars we see at night are bigger and brighter than our sun, some spectacularly so. The stars in the constellation Orion are some of the biggest and brightest we can see.
Take a look at the star Betelgeuse in the upper left-hand corner of Orion. It is easy to spot because of its distinctive reddish color. The strange name has an even stranger meaning, “armpit of the giant.” Astronomers call it a red super giant star and it is truly immense. If we could compress it down to the size of a huge red beach ball as tall as a 10-story building, then the earth would be the size of the period at the end of this sentence.
Looking diagonally across Orion to the lower right-hand corner you will spot another bright star, this one very bright white in color. Its name is Rigel, which means “foot of the giant.” Astronomers call it a blue-white super giant star and its light has taken over 800 years to reach us, which means it is a really bright star. It shines 60,000 times brighter than our sun. Think of all the atomic bombs going off in Rigel!
A planet as close to Rigel as the earth is to the sun would be instantly fried. To have the climate we are accustomed to, the earth would have to be five times farther than Pluto from that very hot star!
Three to see
Check out the three stars of Orion’s belt, one of the most distinctive star patterns in the sky. They are dimmer than Betelgeuse and Rigel but not because they shine less brightly. They are just a lot farther from us. On the right is Mintaka, which means “belt,” is another blue-white giant. It is composed of at least five stars and the two biggest shine at a whopping 90,000 times as bright as our sun each.
On the left, Alnitak also shine tens of thousands of times brighter than our sun. The middle one, Alnilam, takes the grand prize. Estimates put it at almost a million times brighter than our puny little sun.
An interesting thing about all these stars is that they are only a few million years old, much younger than our sun which has reached the ripe old age of about five billion years. These very bright, hot stars are gobbling their fuel like there was no tomorrow. In a million years or so, sooner for Betelgeuse, they will explode as supernovas and be gone forever. The delicate commodity we call life would not have time to incubate on a planet orbiting one of those stars.
Finally, we have a planet to look at in the evening sky. Venus, who has been taking her sweet time hiding out of sight on the far side of the sun, is making an appearance in the western twilight sky. To spot her you need to be able to see low in the west just after sunset. You may need binoculars to find the planet just above and to the left of where the sun went down. Sound too complicated? Just wait a few weeks and it will be a lot easier to see. Sometimes known as earth’s “evil twin sister,” Venus will be a brilliant beacon in the sunset sky for months to come.
The other planets are all out in the early morning sky. Jupiter is high up in the sky, before dawn, with Mars to the lower left and Saturn even closer to where the sun will rise.