New Hubble Image of Jupiter's Red Spot

Astronomers are eagerly awaiting new information about the Great Red Spot, the largest and most colorful storm in the atmosphere of the giant planet Jupiter. The Juno spacecraft just flew as close as 5600 miles over the Red Spot, and the information is coming slowly back to Earth. This giant storm is currently about 10,000 miles wide -- larger than the entire planet Earth -- although it is smaller than when the Voyager spacecraft flew by in the 1970's. Why it has been shrinking and why it's color is so vivid are mysteries planetary scientists are trying to solve. 

In the meantime please enjoy the attached Hubble Space Telescope image of Jupiter, taken on April 3, when the Earth was closest to Jupiter in its yearly orbit. The Red Spot is vividly clear on this wonderfully detailed image, taken from just a few hundred miles above our planet's surface.  (Click on the image to see it bigger.)

Two Giant Black Holes Whirl at the Core of an Active Galaxy

Using the Hubble Space Telescope, a team of astronomers has found that a superbright (active) galaxy is powered at its core by two supermassive black holes whirling around each other in only a bit more than one year. This remarkable galaxy is called Markarian 231, after the Armenian astronomer who made a catalog of such active galaxies (with unusually bright centers.)

The galaxy is almost 600 million lightyears away, so we cannot see the tiny area in the center which contains the black holes directly. But a detailed study of the ultraviolet light from the core of the galaxy strongly implies that a black hole containing enough material to make 4 million Suns is whirling around a much larger black hole (with mass inside for 150 million Suns.)

Think about those numbers! You would not want to live near such overweight black holes, but luckily they are confined to the central regions of galaxies (including our own Milky Way) and are not a feature of the galactic outskirts where our solar system resides in comparative peace.

The idea that enormous black holes like this can share the same environment is not news to astronomers, but it's nice to have such a clear example. We now know that the giant islands of stars called galaxies probably all started much smaller and have been growing through "mergers" (if you'll pardon our appropriating a word from the world of business.)

Smaller galaxies are "eaten" by larger ones, or two galaxies of equal size are attracted together by their mutual gravity. If the smaller galaxies each contain a big black hole, both black holes will wind up near the center of the merged object. If the original galaxies had orbiting motion around each other, their inner black holes will have some of that motion, and can circle each other until -- later -- their gravity also pulls them together.

The fact that the two black holes in Markarian 231 take only about one year to go around means they will collide in a few hundred thousand years (a long time compared to the presidential nomination season, but short for galaxies.)

When two black holes collide you get -- surprise, surprise -- a bigger black hole. But we have caught Markarian 231 in the act of a small galaxy having been swallowed, but before the two black holes had time to merge. There are stars and huge clouds of gas and dust being pulled in by the pair of black holes and as they are torn apart and whirled around, they give off a lot of energy.

It's that energy of doomed material (before it falls into one or the other black hole) that makes Markarian 231's center so unusually bright.

The method used to find the waltzing, whirling black holes in this galaxy holds promise for finding other pairs of giant black holes in other distant galaxies. And the existence of such pairs of hungry black holes is good evidence that our merger theory of how galaxies "bulk up" is correct.

(By the way, our image, above, is a painting, based on the Hubble data.  As we said, we can't take a picture of the inner part of the galaxy.  But below is a Hubble image of the entire disturbed galaxy with its bright center.)

A Baby Galaxy with a Grown-up Black Hole Inside

Using the Hubble and Gemini telescopes, astronomers have found a mystery --  a tiny galaxy that has a huge black hole in its center. That hungry black hole has eaten enough material to make 20 millions Suns!

The baby galaxy is really small -- its diameter is only 300 lightyears.  It's crowded in that little space; it contains about 140 million stars.  (Compare it with our Milky Way Galaxy, which stretches over 100,000 lightyears, and contains at least 200 billion stars.  Yet our central black hole has eaten only about 4 millions sun's worth of material.)  How could such a baby galaxy have such a big black hole?

Astronomers are no longer surprised to discover giant black holes at the centers of most galaxies.  Where a galaxy is most crowded (in its middle) is where a black hole (a star corpse with enormous gravity) has the most "food" to eat and can therefore grow.  But, in general, we have found that the larger a galaxy, the larger the monster black hole at its center.  So finding a baby galaxy sporting such a big black hole comes as a huge surprise.

A clue to this mystery comes from the name of the baby galaxy -- its awkward designation is "M60-UCD1."  UCD stands for ultra-compact dwarf (galaxy), which makes sense.   But M60 refers to the 60th entry in Charles Messier's catalog of fuzzy sky objects published in the 1780's.  That Messier catalog features some of the brightest and easiest to see galaxies and nebulae.   There is no way a tiny faint baby galaxy would have made his list!

It turns out that our baby galaxy is orbiting the much larger and brighter galaxy called M60.  In our picture, you see M60, a huge, blimp-shaped "grown-up" galaxy, which has its own super-massive black hole at the center.  You can see our baby galaxy in the inset of the photo. (You may need to click on the image to see it well.)

The fact that our baby galaxy is a "satellite" of the big galaxy may explain the mystery of its small size and big black hole.  The discoverers suggest that in the distant past, our baby was actually a big galaxy, with many more stars (explaining how it got its big black hole.)  But it had a "close encounter" with M60.  The gravity of the big galaxy stripped away its outer stars, leaving the "victim" of this encounter much smaller. 

If M60 took away and absorbed the outer layers of its neighbor, that would make M60 a cosmic cannibal.  That sounds awful, but in recent years astronomers have begun to realize that just about every big galaxy has grown to its present size by cannibalizing some of its smaller neighbors.  

It's a dog-eat-dog world out there among the galaxies, and the big bullies really get to throw their weight around.  Our little galaxy was once a more regular member of the galaxy club, but it lived in a rough neighborhood and got really beaten up by the local gravity bully.  Now it's a mere shadow of its former self.  

A Beautiful Pinwheel of a Galaxy

A Beautiful Pinwheel of a Galaxy

Taking a break from all the heavy-duty science news for a minute, I want to share a beautiful recent image with you from the Hubble Space Telescope.  What you see on our photo is a large part of a spiral shaped galaxy (or island) of stars, known by its catalog number M83. It is about 15 million light years away in the  constellation of Hydra, the water snake.  

M83 contains billions upon billions of stars and quite a bit of gas and dust -- the cosmic raw material from which new stars, new planets, and perhaps even new Facebook fans can form.

This remarkably detailed image emphasizes the pinkish-red regions that are glowing clusters (or groups) of young stars, seen on the edges of the galaxy's spiral arms.  Actually, the young (adolescent) stars in these clusters glow so hot, they give off not just the light our eyes can see, but also energetic ultraviolet light.  The left-over gas that still surrounds these new star groups (in a way, the womb that gave birth to them) then is set to glow.   The excited gas -- mostly the cheapest, simplest element in the universe, hydrogen -- glows with a characteristic pinkish red.

Just look at all the pinkish glow!  That is to say, see all the new stars that we can see having been born recently -- at least recently on the cosmic time scale, or somewhere between 1 to 10 million years ago.  Like most of our cities in the spring and summer, there is still lots of construction going on in such galaxies.  

A Beautiful New Image from the Hubble Telescope

Here is a gorgeous picture of a spiral galaxy, which is part of the Coma Cluster of galaxies, roughly 300 million light years away. This galaxy (of billions of stars), like our own, is shaped like a frisbee -- and we are looking at the disk of the frisbee face-on. Its name is just a catalog number: NGC 4921. You can see its huge encircling "arms" of countless stars, blending their light together. And notice a number of clusters of young stars glowing blue, a little distance out from the center.

But what is amazing about this image, if you look at it for a while, is how many OTHER galaxies are visible through and around NGC 4921! All those structures around the galaxy that are not precise pinpoints of light are other great islands of stars -- each containing billions of stars and planets. The cluster of galaxies which NGC 4921 is part of contains more than a thousand galaxies. And there are more galaxies beyond that cluster. Pictures like this help us remember that our problems and disagreements on Earth are such minor issues when seen from the perspective of the universe.

This image, by the way, was assembled from a number of Hubble Space Telescope images and processed by Roberto Colombari, an Italian astronomical photographer working in Brazil.

A Gorgeous New Hubble Image and News from Kepler

Scientists working with the Hubble Space Telescope have just released a magnificent new image of one my favorite astronomical objects -- the Horsehead Nebula, a great cloud of "cosmic dirt" in the constellation of Orion. What makes this image a little different from usual is that we are not seeing the tower of dust with visible light, but with heat-rays (what scientists call the "infra-red.") 

It is in such clouds of dust and gas that new stars and planets are being regularly born. Because dust can block regular light, infrared images like this allow us to peer deeper into these regions of star birth. This particular image is about 2.5 light years across (where each light year is about 6 thousand billion miles) -- so we are seeing a good-sized pillar of cosmic "raw material" here. (Yet the Horsehead is just a part of a much larger complex of gas and dust called the Orion Molecular Cloud, which is roughly 1500 light years away from us.)

You can see two recently born stars at the top ridge of dust in the Horsehead in this image, confirming that star birth is happening in this dusty clump. Note that the colors we see on this picture are not real (since these are rays our eyes are not sensitive to.) The colors were picked by Hubble scientists to give a sense of the dustiness of the Horsehead.

You can contrast this infrared picture with a visible-light Hubble image taken with the Hubble in 2000-2001:
http://hubblesite.org/newscenter/archive/releases/2001/12/image/a/

and with an image of a larger region around it taken with the Canada-France-Hawaii Telescope on the ground at:http://www.nasa.gov/multimedia/imagegallery/image_feature_89.html

Aren't they gorgeous images?

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In other news you may have read that the Kepler mission, photographing 150,000 stars regularly in its search for planets orbiting other stars, has found three more planets that are just a little larger than Earth and orbiting in the "habitable zone" of their stars -- where water could be warm enough to be liquid. 

For the full story, see: http://www.kepler.nasa.gov/news/index.cfm?FuseAction=ShowNews&NewsID=243

That page gives you access to the quick info, the paintings of what the planets might like, animation, etc. To get the story in a more organized way, scroll down toward the bottom and click on the link to the full NASA news release.

The gist of the discovery is that we are finding more and more planets that are roughly earth-like -- perhaps a bit bigger, not always around the same kind of star as our Sun -- but Earth-like in their temperatures and other conditions. The Kepler team said that the current discovery is just an appetizer. Many more such planets may be among the 2740 candidate planets Kepler found that they are still examining and not yet ready to confirm.

Extremely Deep View of the Universe

Last month, the Hubble Space Telescope released one of the most impressive astronomical images ever taken and I wanted to share it with you. Called the Hubble Extremely Deep Field, it shows a tiny, tiny portion of the sky in the constellation of Fornax -- a portion about the same size (angle) in our sky as one of the smaller dark splotches (maria) you can see on the Moon.

Between 2002 and 2012, a team of astronomers kept photographing this same bit of sky over and over again for 2 million seconds (almost 23 days) and the results, as you can see, are spectacular. Almost every bit of light you see on the accompanying picture is a galaxy (a collection of millions and, more likely, billions of stars). Some are so far away, light from them is estimated to take 13 billion YEARS to reach us!

This means that when you look at the faintest objects in this picture you are looking almost back to the beginning of time (the Big Bang is estimated to have taken place 13.7 billions years ago.) Some 5,500 galaxies are visible in the small frame of this image and they range in distance and time over billions of lightyears and years. In such images, which are like core samples in geology, astronomers can study the history of structure and matter in the universe.

The Hubble scientists have done this before, taking previous sets of deep images called the Hubble Deep Field and then the Hubble Ultra-deep Field.  But the current image (above) shows by far the deepest view (seeing the faintest galaxies and light from longest ago.)

A Magnificent Cluster of Stars Captured

I wanted to share a remarkable new Hubble Space Telescope image with you. In the accompanying picture, you see a magnificent cluster of over 250,000 stars, a grouping whose catalog number is M9. (This designation comes from a list Charles Messier made long ago of fuzzy objects of interest in the sky.)  The colorful cluster is in the direction of the center of our Milky Way galaxy, some 25,000 light years away. (This means that, traveling at the speed of light, it would take you 25,000 years to travel there!) What's fascinating about this Hubble image -- taken with the Advanced Camera for Surveys -- is how clearly we can see individual stars in this crowded, distant group. (The cluster is so far away and so small that it takes up about as much of the sky as the head of pin, held at arms' length.)

The stars in this cluster are typically older than the Sun and contain fewer of the heavier elements that make life and technology on Earth possible. Such clusters, called globular clusters, are thought to be among the oldest objects in our Milky Way Galaxy.  We study the globular clusters like M9 to learn more about the archaeology of our home galaxy and how things were in our neighborhood long before the Sun and the Earth ever existed.