Category Archives: spitzer space telescope

astronomy news, molecular clouds, spitzer space telescope, starbirth

Stellar Family Portraits

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They Tell us About the Process of Star Birth

Stars are born in messy litters that spread themselves across the sky for hundreds of thousands of light-years. If you look at one of these creches, you can see bright stars still embedded in the clouds that formed them. You can also see the “seeds” of stars — that is, regions where gas and dust is still wrapped so tightly around newly forming stars that they can’t yet be seen.

What starts a cloud of as and dust down the path of starbirth?  If the cloud just sits there with no outside forces acting on it, it will just stay a cloud. But, give it a little push, say from the strong wind of a nearby massive star (which shoves material along ahead of it), or even a supernova blast, and the cloud starts clumping together and swirling around. Eventually the material in the center, which is being compressed by the motion, will heat up. If this happens long enough and there’s enough material to keep the clumping going, a star will eventually form.  This is a very simple explanation for a complex set of processes that take hundreds of thousands of years to start a cloud down the path of starbirth.

The Spitzer Space Telescope (and other observatories) have long studied starbirth regions to understand the star-and-cloud interactions that seem to trigger the births of new stars. The latest picture from Spitzer (NASA/JPL-Caltech/Harvard-Smithsonian CfA) was just released last week  to help celebrate this infrared observatory’s fifth year on orbit. It shows multiple generations of stars all gathered in a big molecular cloud “family home” — a region called W5. This cloud complex is so big that it spans an area of sky about the size of four full moons. W5 lies about 6,500 light-years away from us in the constellation Cassiopeia.

In this image, the blue dots in the centers of the two hollow cavities are the older stars of the W5 stellar family (other blue dots are background and foreground stars not associated with the region). Younger stars line the rims of cavities in the cloud that were carved out by winds from the most massive stars in the area. Some of the younger stars can be seen as pink dots at the tips of the elephant-trunk-like pillars. The white knotty areas are where the youngest stars in the family are forming. Red shows heated dust that is scattered throughout the cavities. The densest clouds are colored green (and, this is a false-color image; the color-coding is there simply to help astronomers separate various regions and structures in the starbirth region).

This image contains some of the best evidence yet for the triggered star-formation theory. And, it’s a stunningly beautiful illustration of just how much we’ve learned about the births of multiple generations of stars by using some of the most advanced telescopes on and off the planet!

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.