Showing posts with label astronomy. Show all posts
Showing posts with label astronomy. Show all posts

Saturday, November 5, 2016

Super Moon

Super Moon photographed in September 2015

The most voluminous Super Moon of the 21st century will be visible on Monday 14 November 2016. Seen from France, the Moon will be biggest at 14h52. That’s not of course an ideal time to get involved in Moon watching, but it will remain spectacularly big throughout the evening. Our celestial neighbor hasn’t been closer to the Earth since 1948. And it won’t be getting any nearer to us for a very long time. So, this is your sole chance to see the Moon at such a small distance that you could truly lean out and touch its surface with a stick no more than 350,000 km in length... if only you could wield such a long stick.

Sunday, September 4, 2016

Just a star away

A stone’s throw ? Not exactly. A little bit more. Aim your stellar pebble in this direction.

Thursday, August 25, 2016

Maybe we have nearby cousins in the universe

When I was a student, the only star whose name I could remember was Proxima Centauri. That was because I had been told that it was our closest stellar neighbor. Today, we learn with excitement that this star has a planet, known as Proxima B, that sounds as if it could be relatively similar to our Earth. Inevitably, we ask the breathtaking question: Could there be, or have been, life on this exoplanet?

That sphere in the foreground is an artist's impression
of the Proxima B exoplanet, which gravitates around
the little orange star in the background.

It’s not exactly just down the road. The distance between Earth and Proxima B is over 4.2 light years. That’s to say, over 40 thousand billion kilometers. But that’s neither here nor there. In more down-to-earth terms, it will probably take our human scientists another ten or so years to use new scientific instruments to tell us whether or not there might be, or might have been, life of some kind on Proxima B.

Saturday, January 30, 2016

Earth collided with another planet, Theia, creating the Moon

About 100 million years after the creation of our planet, a collision occurred between the Earth and a baby planet, Theia, The smaller planet disappeared inside the Earth, but fragments of the amalgam flew off into space, where they coagulated into a new body: the Moon.

A recent study carried out by researchers from the University of California in Los Angeles (UCLA) has revealed that the collision was strictly head-on, which explains why the chemical composition of Moon rocks is quite similar to that of Earth rocks. If Theia and Earth had collided obtusely, then much of the Moon would have been composed mainly of Theia, meaning that the chemical compositions of the Moon and the Earth would have been significantly different.

Sunday, April 21, 2013

Quest for new worlds

It's never too early to start looking around for new worlds that might be colonized, one day, by our human descendants. Incidentally, it's becoming more and more likely that many of these descendants, in the not-too-far-distant future, will be quite different creatures to us, since their genomes will no doubt contain various synthetic genes inherited from top-class intelligent robots. There's no sound reason—other than old-fashioned nostalgia—for hanging around here longer than necessary on the charming planet Earth, with its depleted resources and damaged ecosystems. Adventurous human societies should be able to take advantage of their Earth-based history and experience in order to go about things in a better fashion at other spots in the universe.

We first have to find new worlds, and then our descendants will have to invent some way of reaching them. Theoretically, neither of these two challenges would appear to be insurmountable... though I don't have the least idea of what the solutions might look like. When our descendants get around to finding solutions to the above-mentioned challenges, they'll surely be amazed to think that we old-timers of the start of the 21st century were incapable of envisaging such answers.

Astronomers in search of new worlds evoke the celebrated children's story of Goldilocks and the three bears, by the English romantic poet Robert Southey [1774-1843].

The Goldilocks metaphor is a little like the Down Under joke at the end of one of my recent blog posts [display]. In the empty house of the three bears, in the middle of the woods, the little girl comes upon three bowls of porridge, apparently ready to be eaten. Feeling hungry, she tastes the porridge in Father Bear's big bowl, but it's too hot. Then she tries the porridge in Mother Bear's bowl, but it's too cold. Finally, in Baby Bear's little bowl, Goldilocks finds that the temperature of the porridge is "just right", so she gulps it all down. In the case of planets orbiting around a star, there is sometimes an orbital zone whose temperature, like that of the planet Earth, is apparently "just right" for human existence.

Last week, astronomers were thrilled to announce that NASA's Kepler spacecraft had discovered a pair of so-called exoplanets orbiting within the Goldilocks zone of a star that is henceforth named Kepler 62, located in the constellation Lyra, at a distance of 1,200 light-years from our solar system. Here's an artist's impression of a "sunrise" in the vicinity of one of these planets:

The chief of the Kepler project, William Borucki, claims that this pair of exoplanets is the most favorable site for life that has ever been detected by the Kepler spacecraft since its launch by NASA in March 2009. Click here to visit the Wikipedia page on this project.

Meanwhile, plans are already under way for NASA's next-generation spacecraft designed to look for new worlds. Called the Transiting Exoplanet Survey Satellite (TESS), and designed by teams at the Massachusetts Institute of Technology (MIT) headed by George Ricker, the new vessel will be launched in 2017. Here's an artist's impression of the TESS spacecraft:

The hundreds of small exoplanets discovered by Kepler have all been linked to stars whose great distance means that they're faint. TESS, on the other hand, will examine bright stars in a much larger area of the heavens. So, there's a good chance that this new spacecraft will be able to find new worlds for our descendants.

One might imagine a latter-day Columbus setting out towards obscure shorelines. The TESS adventure reminds me rather of future oak forests planted by conscientious landowners who know full well that neither they nor even their immediate offspring will ever sit in the shade of those great trees.

Wednesday, November 14, 2012

Blue light in the darkness

I came across an article in the French press about an ingenious device that apparently prevents night-time drivers from falling asleep at the wheel. It's simply a blue LED lamp fixed inside the vehicle, in the vicinity of the rear-view mirror, so that it shines into the driver's eyes.

                                         — photo CNRS/Université Bordeaux Segalen

Researchers at the CNRS (French national scientific organization) and the university of Bordeaux explain that the blue light of their embedded anti-drowsiness device acts upon the driver's biological clock by inhibiting the secretion of the melatonin hormone, which is responsible for inducing drowsiness. [For an in-depth presentation of this hormone, look up melatonin in Wikipedia.] According to its inventors, tests of the blue-light technique demonstrate that it's more efficient than coffee in the prevention of drowsiness... which is the main cause of mortal accidents on French autoroutes (highways). They add nevertheless that 17 per cent of their subjects were unable to complete the tests because the blue lamp shining in their faces made it totally impossible for them to drive at all.

Everybody agrees nevertheless that it's preferable to sleep well during the week that precedes any night-time driving, and to pull over for a 15-minute nap as soon as the first signs of drowsiness appear. That explanation about the advantages of sleep as a remedy for drowsiness is a bit like saying that there's no better remedy for hunger than food.

The idea of a life-saving blue light in the darkness reminds me of one of the loveliest short videos I've ever seen, created by the US cosmologist and science author Carl Sagan [1934-1996].

Sagan's origins were Russian, and he started his prestigious career as a popularizer of science by coauthoring a book with the Soviet astrophysicist Iosef Shmuelovich Shklovskii [1916-1985], Intelligent Life in the Universe (1966).

This was in fact the first serious English-language book ever published on this exciting theme, and it fascinated me at the time, in the late 1960s. Unfortunately, it's the kind of book that has dated rapidly and considerably, and the writing style and didactic content hardly match up to the brilliance of today's great authors of popular books on physics such as Brian Greene (The Hidden Reality, 2011), David Deutsch (The Beginning of Infinity, 2011) and Lawrence Krauss (A Universe from Nothing, 2012). Often, when I'm reading, I underline fragments that have impressed me greatly. In the book by Shklovskii and Sagan, I notice that I underlined the following words: (on page 248):
For all our feelings of self-importance, we are only a kind of biological rust, clinging to the surface of our small planet, and weighing far less than the invisible air that surrounds us.
I realize that I've always been attracted to sentiments that downplay human vanity. Be that as it may, here's Sagan's video on the pale blue dot in the middle of the sky:

Talking of extraterrestrial creatures, I would imagine that most of my readers have met up with the marvelous short story by the US science-fiction writer Terry Bisson entitled They're made out of meat. You can find it on the web by clicking here. It's so short that I've taken the liberty of including a copy here:

"They're made out of meat."


"Meat. They're made out of meat."


"There's no doubt about it. We picked up several from different parts of the planet, took them aboard our recon vessels, and probed them all the way through. They're completely meat."

"That's impossible. What about the radio signals? The messages to the stars?"

"They use the radio waves to talk, but the signals don't come from them. The signals come from machines."

"So who made the machines? That's who we want to contact."

"They made the machines. That's what I'm trying to tell you. Meat made the machines."

"That's ridiculous. How can meat make a machine? You're asking me to believe in sentient meat."

"I'm not asking you, I'm telling you. These creatures are the only sentient race in that sector and they're made out of meat."

"Maybe they're like the orfolei. You know, a carbon-based intelligence that goes through a meat stage."

"Nope. They're born meat and they die meat. We studied them for several of their life spans, which didn't take long. Do you have any idea what's the life span of meat?"

"Spare me. Okay, maybe they're only part meat. You know, like the weddilei. A meat head with an electron plasma brain inside."

"Nope. We thought of that, since they do have meat heads, like the weddilei. But I told you, we probed them. They're meat all the way through."

"No brain?"

"Oh, there's a brain all right. It's just that the brain is made out of meat! That's what I've been trying to tell you."

"So ... what does the thinking?"

"You're not understanding, are you? You're refusing to deal with what I'm telling you. The brain does the thinking. The meat."

"Thinking meat! You're asking me to believe in thinking meat!"

"Yes, thinking meat! Conscious meat! Loving meat. Dreaming meat. The meat is the whole deal!  Are you beginning to get the picture or do I have to start all over?"

"Omigod. You're serious then. They're made out of meat."

"Thank you. Finally. Yes. They are indeed made out of meat. And they've been trying to get in touch with us for almost a hundred of their years."

"Omigod. So what does this meat have in mind?"

"First it wants to talk to us. Then I imagine it wants to explore the Universe, contact other sentiences, swap ideas and information. The usual."

"We're supposed to talk to meat."

"That's the idea. That's the message they're sending out by radio. 'Hello. Anyone out there. Anybody home.' That sort of thing."

"They actually do talk, then. They use words, ideas, concepts?"

"Oh, yes. Except they do it with meat."

"I thought you just told me they used radio."

"They do, but what do you think is on the radio? Meat sounds. You know how when you slap or flap meat, it makes a noise? They talk by flapping their meat at each other. They can even sing by squirting air through their meat."

"Omigod. Singing meat. This is altogether too much. So what do you advise?"

"Officially or unofficially?"


"Officially, we are required to contact, welcome and log in any and all sentient races or multibeings in this quadrant of the Universe, without prejudice, fear or favor. Unofficially, I advise that we erase the records and forget the whole thing."

"I was hoping you would say that."

"It seems harsh, but there is a limit. Do we really want to make contact with meat?"

"I agree one hundred percent. What's there to say? 'Hello, meat. How's it going?' But will this work? How many planets are we dealing with here?"

"Just one. They can travel to other planets in special meat containers, but they can't live on them. And being meat, they can only travel through C space. Which limits them to the speed of light and makes the possibility of their ever making contact pretty slim. Infinitesimal, in fact."

"So we just pretend there's no one home in the Universe."

"That's it."

"Cruel. But you said it yourself, who wants to meet meat? And the ones who have been aboard our vessels, the ones you probed? You're sure they won't remember?"

"They'll be considered crackpots if they do. We went into their heads and smoothed out their meat so that we're just a dream to them."

"A dream to meat! How strangely appropriate, that we should be meat's dream."

"And we marked the entire sector unoccupied."

"Good. Agreed, officially and unofficially. Case closed. Any others? Anyone interesting on that side of the galaxy?"

"Yes, a rather shy but sweet hydrogen core cluster intelligence in a class nine star in G445 zone. Was in contact two galactic rotations ago, wants to be friendly again."

"They always come around."

"And why not? Imagine how unbearably, how unutterably cold the Universe would be if one were all alone ..."

Saturday, September 25, 2010

Jupiter scared me

It's all very well to be offered a fabulous early-evening spectacle of Jupiter above the clifftops to the east of Choranche, especially on my 70th birthday, but I wasn't warned, and it gave me a shock last night.

You see, it doesn't twinkle. (Of course, it doesn't, since it's a planet, not a fiery star.) All on its own in the semi-darkness, just above the horizon in the direction of the French Alps, the fixed light in the sky was eerie. I was alarmed that workers might have started to erect a skyscraper on the Vercors plateau. Or was it maybe a gigantic laser device designed to spy on Sophia, Fitzroy, Moshé and me? That seemed to be unlikely, because none of us has run into any trouble with espionage authorities… except maybe Fitzroy, who's a newcomer in the family, and about whom I know little. Was it an intervention of Silvio Berlusconi? No, that fool wouldn't have enough men to install a big lightbulb up there. I concluded that the most likely explanation was the presence of a hovering flying saucer. This reassured me somewhat, but I remained a little spooked.

This evening, I'm unlikely to be disturbed. As of yesterday, I've become older and wiser. Not only do I now know that it's merely the planet Jupiter, but there are so many clouds on the horizon (as is often the case at Gamone) that I'm unlikely to see anything whatsoever.