When they are passing in front of their stars, their atmospheres are backlit in a way that can make spectroscopic analysis of the different chemicals in their atmospheres comparatively easy: the wavelengths of light absorbed by the various chemicals will show up, in a tiny way, in the spectrum of the starlight. And this is what makes it possible to imagine looking at them for signs of life.
What scientists would look for are planets with unstable atmospheres, which James Lovelock said was an indication of life.
After the extragalactic planet post this morning, Sam Arbesman sent me a link to systemic, a blog dedicated to the search for extrasolar planets written by Greg Laughlin, one of the scientists involved in the effort. Here are two relevant posts. In Forward, Laughlin says we’re very close to finding a nearby Earth-like planet:
Detailed Monte-Carlo simulations indicate that there’s a 98% probability that TESS will locate a potentially habitable transiting terrestrial planet orbiting a red dwarf lying closer than 50 parsecs. When this planet is found, JWST (which will launch near the end of TESS’s two year mission) can take its spectrum and obtain resolved measurements of molecular absorption in the atmosphere.
In Too cheap to meter, Laughlin presents a formula for the land value of such a discovery that depends on how far away the planet is, the age of the star it orbits, and the star’s visual magnitude.
Applying the formula to an exact Earth-analog orbiting Alpha Cen B, the value is boosted to 6.4 billion dollars, which seems to be the right order of magnitude. And applying the formula to Earth (using the Sun’s apparent visual magnitude) one arrives at a figure close to 5 quadrillion dollars, which is roughly the economic value of Earth (~100x the Earth’s current yearly GDP)…
RV shifts are how the vast majority of extrasolar worlds have been discovered, but only because these planets, called “hot Jupiters,” are extremely massive and in hellishly close orbits around their stars. Their stellar wobbles are measurable in meters per second; seeing the much smaller centimeters-per-second wobble of an Earth twin is orders of magnitude more difficult. For the Alpha Centauri system, the feat is akin to detecting a bacterium orbiting a meter from a sand grain-from a distance of 10 kilometers. But by devoting hundreds of nights of telescope time to collecting hundreds of thousands of individual observations of just these two stars, Fischer believes she can eventually distill the faint RV signal of any Earth-like planets. It’s simply a matter of statistics and brute force. The planets wouldn’t reveal themselves as images in a telescope, but as steadily strengthening probabilistic peaks.
Live on NASA TV right now: the launch of the Space Shuttle Atlantis, tasked to repair the Hubble telescope. Looks like if the weather holds, lift-off is around 2:01pm. (via @noahkalina)
I am hoping that Moon will be awesome and not just a mashup of 2001 and Solaris. The score is by Clint Mansell, who has scored all of Darren Aronofsky’s movies, most notably Requiem for a Dream. Moon opens on June 12 in NYC and LA. (via sarahnomics)
I was re-reading Carl Sagan’s novel Contact recently, essentially a series of arguments about SETI wrapped into a story, and he alludes to some sort of cosmic Grand Central Station. That, coupled with my longtime interest in transit maps, got me thinking about all of this.
There has never been a generation of humans in all of history who could see such an event. If you ever get a little depressed, or lonely, or think like there’s nothing going on that’s interesting any more, think on that for a moment or two. A thousand generations of people could only imagine such a thing, but we can actually do it.
Man in Space was a short film made by Disney about the possibility of putting humans into space. The film was first shown in 1955 and features several prominent scientists of the day, including Wernher von Braun. The film is available for viewing on YouTube in eight parts.
When I was born 35.2 years ago, a light cone started expanding away from Earth out into the rest of the universe (Minkowski space-temporally speaking, of course). Thanks to updates from Matt Webb’s fancy RSS tool, I know that my personal light cone is about to envelop the Zeta Herculis binary star system, located 35.2 light years from Earth in the constellation Hercules.
With a mass some 50 percent greater than the Sun, however, and beginning its evolution toward gianthood (its core hydrogen fusion likely shut down), Zeta Her A is 6 times more luminous than the Sun with a radius 2.5 times as large. Nevertheless, the star gives a good idea of what the Sun would look like from a great distance, in Zeta Her’s case 35 light years. The companion (Zeta Her B), a cooler class G (G7) hydrogen-fusing dwarf with a luminosity only 65 percent that of the Sun and a mass about 85 percent solar, orbits with a period of 34.5 years at a mean distance of 15 Astronomical Units (over 50 percent farther than Saturn is from the Sun). A rather high eccentricity takes the two as far apart as 21 AU and as close as 8 AU.
Hercules is of course named for the Greek hero, Heracles. Next up is Delta Trianguli, another binary star system, in about two months.
“Holy living fuck…. Are you fucking believing this? Over,” Armstrong radioed back to NASA headquarters nearly 250,000 miles away. “I abso-fucking-lutely am standing on the surface of the fucking moon. I am talking to you from the goddamned fucking moon. Jesus H. Christ in a chicken basket.”
“Holy mother of fuck,” the first man on the moon added.
Your assignment: use the Astrometry and Exif data to stitch all these photos together into a huge Hockney-esque map of the sky. I am also wondering the extent to which you can fool Astrometry with, say, a painting of a portion of the sky. It would be neat if you could submit a drawing of a constellation and get the correct star IDs back. (via mouser)
The mission team estimates Opportunity may be able to travel about 100m per day. But even at that pace, the journey could take two years. The rover will stop to study rocks on the way, and in winter months it cannot move because there is not enough sunlight to provide sufficient power for driving.
Flat-earthers are people who believe, here in the 21st century, that the Earth is flat. (Believers in a round earth are called globularists.)
And what about the fact that no one has ever fallen off the edge of our supposedly disc-shaped world? Mr McIntyre laughs. “This is perhaps one of the most commonly asked questions,” he says. “A cursory examination of a flat earth map fairly well explains the reason — the North Pole is central, and Antarctica comprises the entire circumference of the Earth. Circumnavigation is a case of travelling in a very broad circle across the surface of the Earth.”
If, like me, you have questions about how the Earth could possibly be flat, some of them are answered in the Flat Earth FAQ.
Q: “What about the stars, sun and moon and other planets? Are they flat too? What are they made of?”
A: The sun and moon, each 32 miles in diameter, circle Earth at a height of 3000 miles at its equator, located midway between the North Pole and the ice wall. Each functions similar to a “spotlight,” with the sun radiating “hot light,” the moon “cold light.” As they are spotlights, they only give light out over a certain are which explains why some parts of the Earth are dark when others are light. Their apparent rising and setting are caused by optical illusions. In the “accelerating upwards” model, the stars, sun and moon are also accelerating upwards. The stars are about as far as San Francisco is from Boston. (3100 miles)
BTW, the “ice wall” is what separates the edge of the earth’s disc with outer space or whatever ether or monsters are beyond the earth. We know the wall as Antarctica. I call shenanigans on all this…it’s gotta be a hoax. Nobody’s this ignorant, right? Please?
Laboratory tests aboard NASA’s Phoenix Mars Lander have identified water in a soil sample. The lander’s robotic arm delivered the sample Wednesday to an instrument that identifies vapors produced by the heating of samples.
There are those who believe that somewhere in the vast blackness of space, about nine billion miles from the Sun, the first human is about to cross the boundary of our Solar System into interstellar space. His body, perfectly preserved, is frozen at -270 degrees C (-454 °F); his tiny capsule has been silently sailing away from the Earth at 18,000 mph (29,000km/h) for the last 45 years. He is the original lost cosmonaut, whose rocket went up and, instead of coming back down, just kept on going.
Scientists were recently “astonished” to find water in Mercury’s atmosphere. Plus, the particles in the atmosphere were blasted off the surface by the solar wind so the atmospheric water could indicate that it can be found on the surface as well. First Mars and now this. Has The Onion done a “Scientists find evidence of water on Earth” story yet?
The “Pillars of Creation” may be the most iconic Hubble photograph ever taken. “Located in the Eagle Nebula, the pillars are clouds of molecular hydrogen, light years in length, where new stars are being born,” says Aguilar. “However, recent discoveries indicate these pillars were destroyed by a massive nearby super nova some 6,000 years ago. This is a ghost image of a past cosmic disaster that we won’t see here on Earth for another thousand years or so-and a perfect example of the fact that everything we see in the universe is history.”
Although he said further tests would have to be conducted, Mr Kounaves said the soil seemed “very friendly… there is nothing about it that is toxic,” he said. “It is the type of soil you would probably have in your back yard — you know, alkaline. You might be able to grow asparagus in it really well.”
This site lets you track the International Space Station, the Space Shuttle (when in orbit), and all sorts of other satellites in relation to their position over the earth with a familiar Google Maps interface. Very cool.
Is the universe fractal-like, even on large scales? A group of Italian and Russian scientists argue that it displays a fractal pattern on a scale of 100 million light years. Other scientists aren’t so sure.
Many cosmologists find fault with their analysis, largely because a fractal matter distribution out to such huge scales undermines the standard model of cosmology. According to the accepted story of cosmic evolution, there simply hasn’t been enough time since the big bang nearly 14 billion years ago for gravity to build up such large structures.
At the very moment that humans discovered the scale of the universe and found that their most unconstrained fancies were in fact dwarfed by the true dimensions of even the Milky Way Galaxy, they took steps that ensured that their descendants would be unable to see the stars at all. For a million years humans had grown up with a personal daily knowledge of the vault of heaven. In the last few thousand years they began building and emigrating to the cities. In the last few decades, a major fraction of the human population had abandoned a rustic way of life. As technology developed and the cities were polluted, the nights became starless. New generations grew to maturity wholly ignorant of the sky that had transfixed their ancestors and had stimulated the modern age of science and technology. Without even noticing, just as astronomy entered a golden age most people cut themselves off from the sky, a cosmic isolationism that only ended with the dawn of space exploration.
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