The red giant Betelgeuse — don’t say it three times in a row unless you want Michael Keaton to show up and make your dinner guests dance to the Banana Boat Song — is one of the most familiar stars in the sky for people who live in the northern hemisphere. It’s the right shoulder, and one of the brighter stars, in the constellation Orion, the hunter, which is visible even in the night sky of Columbus, with all of its light pollution.
Supernovas don’t happen every day, every decade, or every century. One famous example occurred in 1054 A.D., when Chinese, Japanese, Arab, and Korean astronomers all reported observing a new star in the heavens, in the constellation of Taurus the bull, that was so bright it could be seen during the day for weeks and did not fade from view at night until two years later. Modern astronomers believe that the ancient astronomers were seeing a supernova that now appears as the Crab Nebula. Being able to observe a supernova in real time, with the sophisticated technology that is now available, would undoubtedly allow humanity to add significantly to its understanding of the death throes of a star.
And here’s a mind-blowing point. As I write this, Betelgeuse may already have exploded. In fact, it might have already exploded when Columbus sailed for the New World in 1492, or the American Revoluation began in 1776, or World War II ended in 1945. We don’t know for sure, because the light from Betelgeuse takes about 600 years to reach Earth. Whenever you look up at the stars in the night sky, you’re always looking into the past.
Astronomers bemoan the amount of light produced by cities and suburbs at night. The bright glow from below interferes with their ability to see the stars above.
I saw a good example of the “light pollution” as I flew into Newark on a clear night earlier this week. Ironically, the light from the houses, parking lots, and shopping centers on the ground reminded me of the stars and constellations of the evening sky.
Before you start worrying that little green men might appear on your doorstep tonight, take a deep breath: the Earth-sized planet is closer to Alpha Centauri B than Mercury is to the Sun, so it’s probably not conducive to life. Still, the discovery is remarkable. In the not too distant future, scientists will use this detection technology to find a planet about the size and mass of Earth, orbiting a star a lot like Sol, at a distance that would suggest that it is likely to be temperate. What will that mean? My guess is that we will train every radio telescope and sensory device we have in the direction of that planet, listen as hard as we can, and hope.
Venus is on the move today and tomorrow. It’s traveling slowly across the face of the Sun, on a journey that astronomers call being “in transit” — as if Venus were hopping a subway to get from one side of the solar system to another.
These kind of astronomical events are very cool, because they happen so rarely. There’s a “music of the spheres” sort of celestial harmony to Venus’ journey that reflects a special, highly unusual confluence of positioning of the Sun, Venus, and Earth. It won’t happen again for 105 years. By then, we hope, the European debt crisis will have been resolved. In fact, some astrologers are saying that the transit of Venus might help to solve such problems. It’s is supposed to herald in a new era of spiritual and technological revolution . . . or, it’s supposed to strongly accentuate feelings of love and hate. With astrology, it always seems to be one or the other.
As with any solar celestial phenomenon, the news stories always caution people not to look directly at old Sol. It’s hard to believe anyone would try to use the naked eye to check out the Venus transit, because Venus will be only a small speck against the enormous disk of the Sun. You supposedly can see it safely by creating one of those pinhole-in-a-box projectors that the news stories typically mention in these circumstances. I tried to make one of those devices when there was a solar eclipse during my childhood, and I gave up in frustration when it didn’t work. This time, I’ll just rely on the photos, and in the meantime wish Venus well on her cross-town travel.
Of course, galaxies are mostly empty space, so whoever is left on Earth when the galactic convergence occurs isn’t likely to see suns and planets smashing into each other. But the night sky will look different. Orion and Taurus and Ursa Major will have lots of company.
Continuing developments in telescope technology are causing astronomers to increase their estimates of the number of Earth-like worlds in the universe.
The latest disclosure deals with the existence of “red dwarf” stars, which are dimmer and smaller than the Sun. Until recently, telescopes have not been sufficiently powerful to detect such stars in other galaxies. Enhancements to telescopes, however, have allowed astronomers to determine that red dwarf stars are far more common than was previously suspected. Indeed, astronomers believe that such stars are 20 times more prevalent in older galaxies than in our galaxy. As a result, astronomers also are concluding that there likely are many more Earth-like planets orbiting those stars — possibly trillions of Earth-like worlds.
Trillions of Earth-like planets? The concept is provocative, because increases in the number of planets logically also increases the likelihood of life, and therefore intelligent life, on at least some of those faraway planets. And the follow-up question is even more provocative: would the existence of intelligent extraterrestrial life be good or bad? Would we rather be the only intelligent life forms in the universe, or would we prefer to learn that we are not alone — indeed, that intelligent life is as common as the fish in the sea? How comfortable would humans be with the knowledge that they live in a crowded neighborhood, where neighbors might drop in for a visit at any moment?
The space-based telescopes keep making amazing discoveries. The latest is the Hubble space telescope’s identification of the most distant galaxy ever detected — a galaxy that is more than 13 billion light years distant from Earth. That means that the light we are seeing now has traveled for 13 billion years to reach our space. In fact, the light we are seeing from that galaxy emanates from stars that blazed only 600 million years after the Big Bang. Those stars almost certainly exist no longer, having long ago gone supernova or turned into one of the other stellar objects that are created when stars die. In that sense, the Hubble telescope is a real-life time machine that allows us to peer into the distant past.
The Hubble space telescope
Astronomers will study the new discovery with great interest, because it may help to provide answers to some very provocative questions. What was the life cycle of early stars, whose intense heat produced the heavy element “star stuff” (to use Carl Sagan’s phrase) of which our universe is made? How did the earliest galaxies form? Why is light from such galaxies visible through the “fog” of hydrogen that should have resulted from the Big Bang?
We can expect more amazing discoveries along these lines as new ground-based and space-based telescopes using new technology come on line and begin to probe the heavens.