Image Credit & Copyright: Rogelio Bernal Andreo http://www.deepskycolors.com/.
I’d like to get your mind working a little bit today, aside from seeing this incredible image from Mr. Andreo, I hope that you read this through because I think you may enjoy it.
As summer fades into fall so to the constellations of the summer night give way to the familiar Winter Hexagon of the Orion neighborhood. Orion is of course, one of the most familiar regions in the night sky but there may be something you haven’t yet given thought to that may just change how you look at this constellation. Let’s have a look.
The Orion constellation is dominated by eight highly visible stars as well as the area around M42, the Orion Nebula, also known as the sword in the hunter’s belt. Orion is also home to some of the most amazing nebulae that the winter sky has to offer but that’s a post for a different time. In this post we don’t care about what size and composition the stars are. In this post we will just touch on the distance to the naked eye points of light that make up the hunter.
Have a look at this distance list of the major players in the constellation Orion. This list is compiled in distance order and not by the anatomic locations on the constellation.
BELLATRIX (left shoulder): 240 light years away.
BETELGEUSE (right shoulder): 427 light years away.
SAIPH (right foot): 720 light years away.
RIGEL (left foot): 770 light years away.
ALNITAK (left belt star as we see it): 800 light years away.
MINTAKA (right belt star as we see it): 900 light years away.
MEISSA (Orion’s head): 1000 light years away.
M42 ORION NEBULA: 1300 light years away.
ALNILAM (middle belt star): 1340 light years away.
Let’s break this down a little further then as soon as the opportunity arises, go outside and look up when you wake up for work or school and realize that many of the stars in the Orion constellation are closer to us here on Earth than they are to each other!
For example, if you lived on a planet around Bellatrix which is the left shoulder star across from Betelgeuse, and you wanted to visit some old friends on Earth you would have to travel 240 light years. After returning home to Bellatrix, you get the urge for a milkshake at that hopping 50’s diner on that planet around the middle belt star Alnilam; well, you would have to travel at least 1100 light years in the opposite direction. I say at least because the actual distance between the two is actually greater once you include the side to side distance as well. Remember, we’re just talking about raw straight line distance from us on Earth. In fact, the only star in Orion closer to Bellatrix than the Sun is Betelgeuse……and just barely!
Let’s do it again from a different angle. Let’s assume that you lived on a planet in orbit around Betelgeuse and you wanted to hit up your favorite gym at that planet around Meissa the head star in Orion and the closest star to Betelgeuse in the constellation (as we see it). If you just found a suitable gym here on Earth instead of traveling to Meissa you would save yourself a 575 light year trip each way!
One final thought experiment. Let’s assume all the stars in Orion cease to shine in unison, right now. Your great grandchildren may see the 1st star, Bellatrix, Orion’s left shoulder, blink out of existence in 240 years but surely none of our grandchildren will be here to witness it. 187 years after that and nearly a half a millennium after it burned out, the red supergiant and right shoulder star, Betelgeuse disappears from the night sky. 293 years after that, we lose Orion’s right foot, Saiph and 50 years after that we lose the other foot, Rigel. In the year 2784 the constellation of Orion will be unrecognizable as both stars representing its shoulders and feet are gone. But the light from the three belt stars, the head star and M42 are still incoming. 30 years after losing Rigel we finally lose the first belt star, Alnitak, the left belt star as we see it from Earth. 100 years later the right belt star, Mintaka goes dark. 100 years after that and 1000 years after the stars went dark we lose Meissa, the head star in Orion. We’ve now clicked into the next millennium, it’s the year 3014 and all that’s left from the incredible Orion constellation is the Orion Nebula region and Alnilam, the middle belt star. As those distant generations view Orion in the digital records of history it’s all but gone. About 300 years later, after that generation’s great grandchildren come and go, the region of M42 (assuming that entire region went out together) disappears leaving only the middle star in what once was the belt of the mighty hunter. But that won’t last long, as just 30 years after being left alone, the light streaming to us from Alnilam runs out, making Orion once again, a ghost in mythology and folklore.
Pretty incredible right? I got the idea for this post from a tweet sent on August 27 of this year by NASA astronaut Doug Wheelock. He posted an image of Orion with the words, “Some of these stars in Orion are closer to Earth than they are to each other.” Needless to say, my mind has been running with that thought for a while now. One of the hardest things to do is to look up at the night sky and see the many constellations and asterisms as three and four dimensional tapestries. Exercises like this are not only fun and mind-blowing but it helps to give you a better understanding to the true vastness of the universe. I hope you all enjoyed this short post and I hope it was effective in its delivery and content. As always, feel free to let me know what you think!