How Unnaturally Natural

What could be more unnatural looking than this shot of an open cluster of stars, an emission nebula, a reflection nebula, and a dark nebula all interacting in the constellation Sagittarius.

"Whoa, back up a bit," you must be saying. "Emission nebula? What's that?"

In side of that picture of Trifid Nebula, there is a lot going on. This picture by the way was taken in the night sky over Abilene, Texas.

But to answer your question, we should look at each individual thing in this picture.

This is the Rosette Nebula in the constellation Monoceros (mo-nos-er-os). The nebula surrounds a young star cluster. This nebula is emitting its own light, due to the presence of ultraviolet radiation from the very hot young stars that make up the cluster. This radiation, although not visible to the eye, is strong enough to 'excite' the atoms in the interstellar dust and gas so that they 'jump' to different energy levels and emit their own form of radiation which can be seen in the nebula's light spectrum. It is not simply reflecting the light from the cluster.

But a reflection nebula does. Reflection nebulas reflect light from a nearby star. Many small carbon grains in the nebula reflect the light. The blue color typical of reflection nebula is caused by blue light being more efficiently scattered by the carbon dust than red light. The brightness of the nebula is determined by the size and density of the reflecting grains, and by the color and brightness of the neighboring star(s).

Dark nebula, also seen in that first picture. This is a good example of a dark nebula, which is one that is blocking the light from whatever is behind it (which could make a shape - in this case, a horsehead).
You will find these in an emission nebula, which as I should have mentioned is a cloud of a high temperature gas. The atoms that are in the cloud get energized by light from a close star. These types of nebulae are usually red because of the amount of hydrogen.

Pacman

Yes its true, I do like the idea of a telescope in space, cutting through all of the fuzziness of the night sky, out there in the cold darkness of space. When I post pictures of what the Hubble has done, I am ignoring what some folks are doing right in our own backyard.

If you think about it Junior, this is where you most likely will have your greatest moments starring at the sky. Although, you are on the verge of a time when you may be able to be a space tourist. Possibly even to the Moon.

This photo was done by a guy named Greg Morgan from Clovis, California. Officially called NGC 281 it is approximately 10,000 light-years away, give or take a few hundred light years in the constellation Cassiopeia. It is sometimes called the Pacman Nebula.

Hubble is still busy!

I caught a show on PBS the other night that was all about the Hubble repair. It was amazing how many tools they had to invent, how much training went into it (they actually practice in a shuttle sized pool) and how one mistake, like a lost screw would have made the mission all for nothing.



If you are interested - and I sure hope you are, you can watch the whole show here! Get some popcorn and a drink and settle back in your chair. This is amazing stuff!

Hubble Snaps some Cool Shots

Remember when I told you about the Hubble mission and the update it was receiving. I told you how this would be the last time - even though what these astronauts did will last the massive telescope a decade.

The first shots are up and posted. This is one of the Butterfly Nebula
It's colorful "wings" are actually cauldrons of heated gas ejected from a dying star that was once about five times the mass of the Sun. The star is now discharging a stream of ultraviolet radiation that makes the cast-off material glow.

This is Omega Centauri.

There are about 10 million stars here. Most of the stars seen here are white-yellow, similar to our Sun. The orange stars are further into their lifecycle, having become larger and cooler. They'll continue to cool and expand in size, eventually becoming red giants seen here as the bright red dots.

This is Stephan' Quintet. Don't be fooled into thinking that they are all right together. They're not.

The galaxy in the upper left is believed to actually be seven times closer to Earth than the rest of the group. The three other galaxies have distorted shapes, elongated spiral arms, and gaseous tails as evidence of their close proximity.

Here are the high resolution shots.

Saturn animation

It has been awhile since I posted here and I apologize for that. Life interrupts a good deal of my best intentions - as you will find out as you grow up and grow older Junior. I just hope that your interest in the night sky will not wane in the process. Building on what you know at age twelve is a lot easier than trying to build on your knowledge at age 52 - not impossible just harder.

Here is a link to a great Saturn animation I found that might interest you. It was compiled over a six year period.

Mars, finally

I will never stop marveling at what new technology can bring. For you, it is as natural as waking up. The latest comes from Google Earth, which your dad should download for you here.

Here is what it will shows of Mars. Yes, Mars!


And if the clouds ever clear, you need to check this out this weekend. And tell me about when I get here next week..

Tripping the Light Fantastic

As you look at those stars on the night sky, you should always keep in mind that what you are seeing is what happened a long time ago. For hundreds, if not thousands of years, geniuses such as Einstein and Isaac Newton and even further back to ancient Greeks and Persians wondered about light. For a really long time, it was believed that light could travel at any speed through space because, in those days, before telescopes, ancient stargazers believed that there was nothing to block the light. So they thought it could speed up and slow down.

But now we know differently. Space is not as empty as everyone once believed and the speed of light is one of those amazing things that stays the same, no matter what. This is a good thing if you think about it for a second. Because light can be counted on to behave the same near earth as it does billions of miles away, we can make predictions about what to expect.

Consider this image, done to simulate exactly how fast light travels from the Earth to the Moon. It takes 1.25555 seconds. The light from the sun takes eight minutes to get to us.

I remember you telling me what you learned when you did that project on Einstein a couple of years back. You told me that light traveled 186,242.4 miles a second. How fast is that? Suppose you were shine a light from Bend to New York on the other side of the United States. That beam of light would travel back and forth 60 times in a second.

This galaxy is the farthest light has traveled, measured by Hubble at 13 billion light years away. The universe was only a billion years old when this galaxy (on the right) began to send its light out, so long ago, the earth wasn't even here yet. Because that is so fast, it is almost impossible to imagine. Look at your Mom across the room. What you are seeing is not what you think. It actually happened 20 billionth of second ago. Now imagine that our Milky Way is 100,000 light years across. In terms of galaxies, that's not very large. But it does require a very large imagination to try and picture that king of event.

This is the closest galaxy to us at 42,000 light years away.