Category Archives: extrasolar planets

exoplanets, extrasolar planets, HII regions, molecular clouds, origins of life

The Science of Life

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What Came First?

Yesterday I was at an all-day symposium about the Origins of Life, held by the Radcliffe Institute and the Harvard University Origins of Life Initiative. The keynote speakers covered some of the major bases in a very complex field of play and I came away with the notion that there are no “chicken and egg” questions here, only a lot of people wondering which PART of the egg came first.The image “https://i0.wp.com/www.eso.org/public/outreach/press-rel/pr-2008/images/phot-06-08-preview.jpg?resize=397%2C307” cannot be displayed, because it contains errors.

While I was at the meeting, a couple of press releases plopped into my Email box. Both of them were about subjects that come up whenever you talk about origins of life in the universe. The first was from the European Southern Observatory, showing an artistically beautiful set of data from astronomers who have mapped the distribution of material inside a dark nebula called the Corona Australis molecular cloud. Molecular clouds are places where astronomers have found a number of organic molecules needed for the creation of life. They’re also quite dusty, threaded with the metallic minerals that life also needs. So, it stands to reason that such places would be part of the “egg” that we study when we ask questions about how life got started here on Earth. This is because the solar system formed from such a cloud some 5 billion years ago.

The ESO image is actually a composite of near-infrared scans of the cloud made using an instrument sensitive to such wavelengths. Near infrared light helps astronomers probe the insides of such clouds to understand how they form and evolve.

The other press release that landed in my IN box was from the University of California at Santa Cruz and deals with exoplanets, another piece of the “origins of life” egg. These are worlds around other stars, and are places where we hope to find more life in the universe, some day. In particular, the news here is that a new study suggests that a planet similar to Earth (a “terrestrial type”) could be orbiting one of the stars in the Alpha Centauri system, the closest stars to our own. They lie about 4.3 light-years from us, which for celestial neighborhoods, is basically the house next door. If it does exist, might it look like Earth (as shown in this artist’s conception, done by Mark Fisher)? We won’t know until we find it.

Now, the news here is really that the planet MAY be orbiting the star and that astronomers could detect it using techniques that are in use today to look for stars around other planets. The techniques, which came in for some discussion at Radcliffe yesterday, center around using something called the Doppler detection method. It doesn’t image a planet directly because finding something as small as a planet in the glow of a star’s light is quite difficult, if not impossible in many cases. The Doppler method measures the shifts in light that we see coming from a star as a planet orbits around it. The gravitational pull of the planet is just enough to cause the star to wobble, and that affects how it looks through a spectroscope (the instrument used to study the spectra of light coming from objects).

Detecting the wobbles from big planets, what are often called “Jupiter-sized” planets is pretty straightforward because they induce big wobbles. Little planets, like potential Earth-like ones, cause small wobbles. These are harder to detect. But, according to a computer simulation done by the folks at UC-Santa Cruz, it can be done. The two astron0mers who did the study, Gregory Laughlin (of UCSC) and Debra Fischer (of San Francisco State University), are now leading an international program to study Alpha Centauri using the 1.5-meter telescope at Cerro Tololo Inter-American Observatory in Chile. They are hoping to find real planets, based on their simulation and using the technique of Doppler detection.

These two studies are chewy and tasty pieces of the larger pie that is the search for life (and its origins) in the cosmos. It’s only a matter of time before those other planets will be found (if they’re there). We continue to study how life began on our own planet. What we learn should be helpful if and when we ever find life elsewhere in the cosmos.

extrasolar planets, intelligence, life, planets, spitzer space telescope

Alien Life, Distant Worlds, and Us

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Worldly Thoughts

 

I woke up this morning thinking about the latest discoveries of planets around other stars. Astronomers are using a variety of techniques to find them, and totals are racking up quickly. Most of the planets that have been found are “Jupiter-like,” meaning they are gas giants with huge atmospheres. They’re relatively easy to find because of their size. Worlds like Earth (the terrestrial worlds) are smaller, and tougher to spot. But because astronomers have been able to spot the environments in which planets form around stars (that is,in clouds of gas and dust), it’s pretty likely that there are many terrestrial planets out there, too. We just have to dig into those clouds and come up with the planets. Which will take time and some sophisticated astronomy search methods.

Yesterday, the Spitzer Space Telescope folks released news that Earth-like planets might form around many of the closest Sun-like stars. This orbiting telescope, which is sensitive to infrared light (think “warmth”) was used to study dust envelopes around nearby stars. These are warm places. Dust closer to the star is hotter than dust farther away from the star, the warm dust is a fair indicator of the types of materials that form rocky planets—that is, Earth-like worlds. Such discoveries always lead to the old question, “Is there life out there?” It’s a fair one to ask.

For now, the definitive answer is “No.” But, that’s because we haven’t seen the evidence for any other life out there. Yet. We don’t have communications from that life, or pictures of it, or any other manifestations of it that we recognize as a definite “signal.” But, if it’s out there, there’s some chance that we’ll detect it. Some day.So, what I woke up thinking about was what life on OUR planet will be like once we discover life somewhere else. Will it change us in some non-physical way? Will our thinking change about life? About politics? Religion? Education? Science? The way we treat our own planet?

Life from “Out There”—Threat or Learning Experience?

Courtesy SwapmeetDave.

The concept of life elsewhere is a major staple of science fiction stories. Depending on the story being told, the life from “out there” can be threatening, friendly, super-intelligent, simple, primitive, or depicted as being far beyond what we can comprehend. In reality, the life we find beyond Earth will likely be some combination of these factors, and perhaps look nothing at all like what we expect. How that life will act? Well… like we do with our deities, humans have painted aliens with a palette of characteristics that we most admire and/or fear in ourselves. When we DO get to meet other forms of life, the experience may teach us a bit more about respecting the life forms we share Earth with.Wonder about why I say that?Well, consider for a moment what humans and human activity (such as whaling) looks like to the cetaceans that inhabit our planet. Or, think about what our planet might look like to alien visitors who come in search of us and they find how we’ve treated our environment.These may be extreme examples, but the point I’m trying to make here is that the search for intelligent life (and other planets) isn’t one-sided. If there’s somebody out there looking for life elsewhere, and they find US, will we inhabit their worst nightmare or exemplify their fondest wishes? Either way, the possibilities are thought-provoking.