…the true legacy of the Hubble Space Telescope, its true gift to the future, is the one we have given ourselves. We have seen farther. Across an ocean of space and time and galaxies, we have seen where we truly are and, therefore, what we truly are.
Each week a group of women meet for a potluck lunch and to play Trivial Pursuit, something I had only done once or twice prior to becoming involved with the group. Each question card has questions from six categories such as Arts & Entertainment, Geography, Sports, Literature, etc. The deck we use seems to have questions slanted towards the U.S. (although the game was developed by two Canadians). There is a conspicuous lack of questions related to any of the sciences or to mathematics.
The Hubble telescope was launched 24 April 1990, 25 years ago. Astronomy seems to be the science most subject to criticism from legislative budgeteers and, just behind evolutionary theory, from creationists.
As a kid, when I learned our sun would die in 5 or 6 billion years, I became afraid and worried. At that time I didn’t realize that life would be extinguished before the sun would die (according to a study released in 2013, the Earth may become so hot in 2.8 billion years that microbes won’t survive). If I had known that the Andromeda galaxy (our closet neighbor) and our Milk Way galaxy were going to merge in about 4 billion years, I would have worried more.
It seems every other week there’s something published about life on other planets or in other solar systems. Or about the discovery of a planet that might support some form of life. Those are soon followed by an article (sometimes from a scientist, sometimes from another) that disputes the finding.
Does life exist elsewhere in our universe? If yes, is it intelligent as we define intelligence? Are we as smart as they? Is it DNA-based? Will we be able to trade them blankets? Will they think we’re pretty? Do they believe the same creation story some of us do? Do their computers suffer from malware?
The distance from Earth to the farthest known edge of our observable universe is about 45.7 giga light years. Light travels at 186,000 miles per second (about 5.9 trillion miles per year) So those bodies at the edge of our universe are about 268 followed by 21 zeros miles away.
What’s in all that space?
- Our solar system containing one star
- Our galaxy with between 200 to 400 billion stars
- An estimated 170 billion galaxies in the observable universe
- Some giant spiral galaxies have up to a trillion stars in them
- So the estimated number of stars is 10 to the 24th (a septillion, or 10,000,000,000,000,000,000,000,000)
- Number of universes = ?
The numbers are huge. Putting them into perspective, the Powerball website says the probability of winning the jackpot is 1 in 175,223,510. With that many stars – even if many are red dwarfs and likely incapable of supporting life-sustaining planets – the odds might seem good that life exists somewhere out there. Given the near impossible-to-comprehend distances and the fact that to approach the speed of light (the fastest anything can go – as far as we know) a body’s mass must be extremely small, it seems unlikely that they or we will make house calls. To put the distance in perspective, if – via a radio signal (which travels at the speed of light) – we send the recording of Louie, Louie into space, it will take 100,000 light years for the signal to escape our Milky Way.
For life to occur, according to current thinking, planets must, like Baby Bear’s porridge, be just right: not too big, not too small, not too far from their star, and not too close to their star. But what if elements of the universe operate not by our standards, but by some other set? Our concepts of life are based on our experience on Earth, but might there be sentient beings who can inhabit other “soups”?
Mercury, Venus, Mars, Saturn and Jupiter were known to Babylonian astronomers in the second century before the common era. In the 18th century Sir William Herschel discovered Uranus. Credit has been given to the 19th century astronomer John Couch Adams and mathematician Urbain Jean Joseph Le Verrier with finding Neptune. In the 20th Clyde Tombaugh was credited with finding Pluto. In the 21st Eris was located by a Mt. Palomar Observatory team: it, like Pluto, is categorized as a dwarf planet. Only our planet Earth has been believed capable of supporting life. Then,
…in 1995, astronomers found the first planet to orbit another sun-like star. The planet wasn’t like ours at all – more massive than Jupiter, and orbiting so close to its parent star its temperature is over 1,000C. But it was a watershed moment. We finally knew that other planets exist.
Thus wrote Phil Plait for the BBC, He continued:
Since then, NASA’s Kepler space telescope, the European Space Agency’s Corot mission and ground-based instruments have found nearly 800 other planets, and that number grows every week. We know of enough planets orbiting other stars that we can actually start to extrapolate some numbers: it looks like approximately half of all stars in the galaxy have planets, and planets may in fact outnumber the 200 billion stars in the Milky Way.
Through Hubble we’ve learned that the rate of expansion of our universe is increasing, not decreasing as previously thought. But we don’t know why. Hubble, like most everything in science, can help us answer questions while raising new questions.