Category Archives: astronomy

astronomy, astronomy research

The Universe Keeps Comin’ At You

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Delivering All Kinds of Goodies to Study

Yesterday I talked about how all time is local, in essence, and that the universe’s activity flows along the lines of time.  We get to divide the time into units that humans can understand, but the universe itself doesn’t care about how WE divide it up. It just keeps doing its thing.

One of the things it just keeps on doing is showing us new objects. The universe’s structure is divided into large-scale structure — like galaxy clusters and superclusters.  These stretch across huge expanses of space. In a given supercluster, light from one “end” of the cluster might travel hundreds of millions of light-years to reach the other “end”. They’re huge.

Small-scale structure “lives” inside the large-scale structure. This would be stuff like individual galaxies, globular clusters, stars, and planets.  Humans are at the “micro structure” end of things, comparatively speaking. As we humans keep extending our gaze out beyond our home planet, we keep finding new variations on the “stuff” of the universe. Take planets, for example.  Throughout most of OUR history, we only knew about the planets we could spot from Earth’s surface using our trusty Mark I eyeballs.  So, we had Mercury, Venus, Mars, Jupiter, and Saturn. That lasted until astronomers invented telescopes and aimed them to the skies — thereby allowing us to extend and magnify our vision.

An artist's concept of an exoplanet called WASP-12b. It's the hottest known planet in our galaxy and probably won't last too much longer. Its star is devouring this world. ravitational tidal forces from the star stretch the planet into an egg shape. The planet is so hot that it has puffed up to the point where its outer atmosphere spills onto the star. An accretion bridge streams toward the star and material is smeared into a swirling disk. The planet may be completely devoured by the star in 10 million years. The planet is too far away for the Hubble Space Telescope to photograph, but this interpretation is based in part on analysis of Hubble spectroscopic and photometric data. Credit NASA, ESA, Greg Bacon.

Today we know of eight planets in our own solar system, dozens of dwarf planets, and — astonishingly to folks who haven’t followed all the latest news — HUNDREDS of planets around other stars.

Last year, I reported from the American Astronomical Society about the first planets found by the Kepler satellite. This year, there will no doubt be more discussion of MORE planets found, followed up by discussions of the characteristics of those planets. They range from supersized hot worlds to places only a bit larger than planet Earth. Kepler is specifically scanning the sky looking for the light signatures of planets that are roughly the same size as Earth. In the process, it has found more than 700 planet candidates and confirmed eight of those candidates as actual planets.

And, the search for planets isn’t limited specifically to Kepler. Ground-based surveys are turning up new planets all the time — and in fact, the first exoplanet was discovered in ground-based data.

This continual discovery of new planets, most in the Earth’s neck of the galactic neighborhood bodes well for the existence of worlds elsewhere in the galaxy — and beyond. That we haven’t seen them yet doesn’t matter.  We will.

Beyond the search for other planets astronomers are stretching our collective vision out to study other stars, gathering data that helps them understand how stars work, how they form, how they live, and how they die. In the process, they also learn about how our own star was formed — and the “stuff” of the interstellar medium that is necessary for the formation of stars and planets. This also helps them study galaxies, and the influences that these stellar cities have on the stars and planets and nebulae — and black holes — that populate them. Every discovery uncovers something new that we didn’t know about the universe before. Each finding adds to our collective store of scientific knowledge. What we find is limited only by our ability to see and understand what is discovered. I don’t know about you, but I find this quite exciting. Our universe will keep throwing this stuff at us; it’s our job to step up, take it in, and add to our scientific treasury.

astronomy

Happy New Year … Here on Earth

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But What does the Cosmos Care?

It’s the New Year here on planet Earth, and we’re all celebrating, resolving new behaviors, and getting on with the business of life, acting for all the cosmos as if something portentous had just happened when one second ticked over to another on our Earth-based clocks. Certainly it was momentous… for those of us on and near Earth.

For the rest of the universe, time flowed on without the temporal milestone that we humans like to impose on the passage of time during this season. What do the stars care what year it is?  For a star, one moment is pretty much just like another one.  One second of burning fuel to shed light to warm nearby space (and any possible planets) flows to the next.  The same thing holds true for the cosmos at large. For galaxies and their stars and the dark matter halos and the galaxy clusters and the quasars, time isn’t really an issue of interest. Cosmic events take place as they are meant to occur and as governed by the laws of physics, gravity, and quantum mechanics. We understand that because we can observe the universe doing what it does and we can use these laws to explain and help us understand those activities. That’s the very cool thing about science, especially astronomy.  We can observe and explain using understood laws of nature.

But, you might suggest, time is important to us. That’s true.  We are a time-binding species of life. We can’t imagine perceiving or understanding the universe without using time as a kind of measuring device. And, that’s cool. But, that’s the way WE see things.

Stars and galaxies and planets don’t count time.  They are part of the time flow in the sense that their events (their creation, evolution, and deaths) all take place in a linear time flow. But, they don’t have “New Years” in the sense that we do. That is, I suspect, a purely human construct that helps us divide the time flow into something we can understand.

Still, time IS an important factor — it began when the universe did, in the Big Bang.

Now, the Big Bang is fascinating — and it’s a nice topic to start out with on January 1.  The Big Bang is the beginning of the flow of time and the distribution and creation of matter throughout the universe. It began with the universe in a state of existence as an infinitely dense and hot singularity. How long it existed in that state is unknown. At some point, however, something kick-started this singularity into an expansion that continues to this day. It’s not an expansion of matter, like an explosion. In fact, an explosion is not really a good analogy for the Big Bang, which was really the beginning of an expansion of space, carrying the newly created matter of the cosmos (hydrogen, helium,  and a little lithium) along with it. From that matter the first stars were created a few hundred thousand years after the Big Bang, and from those stars came the other elements heavier than hydrogen and helium.  And, of course, from those elements, came other stars, planets, and us — all in good time.

So, on this birth of the new year, which flowed naturally from the last moments of 2010, it’s interesting to contemplate the new universe, born some 13.7 billion years ago — as humans count time.  For the universe, 2011 is simply the continuation of the expansion of space and time, and the continual births and deaths of stars, collisions of galaxies, creation of planets, and the evolution of life in places where it can exist.