Tag: Milky Way Galaxy

News from Space: New Map of the Universe Confirms The Big Bang!

planckAfter 15 months of observing deep space, scientists with the European Space Agency Planck mission have generated a massive heat map of the entire universe.The “heat map”, as its called, looks at the oldest light in the universe and then uses the data to extrapolate the universe’s age, the amount of matter held within, and the rate of its expansion. And as usual, what they’ve found was simultaneously reassuring and startling.

When we look at the universe through a thermal imaging system, what we see is a mottled light show caused by cosmic background radiation. This radiation is essentially the afterglow of the Universe’s birth, and is generally seen to be smooth and uniform. This new map, however, provides a glimpse of the tiny temperature fluctuations that were imprinted on the sky when the Universe was just 370,000 years old.

big_bangSince it takes light so long to travel from one end of the universe to the other, scientists can tell – using red shift and other methods – how old the light is, and hence get a glimpse at what the universe looked like when the light was first emitted. For example, if a galaxy several billion light years away appears to be dwarfish and misshapen by our standards, it’s an indication that this is what galaxies looked like several billion years ago, when they were in the process of formation.

Hence, like archaeologists sifting through sand to find fossil records of what happened in the past, scientists believe this map reveals a sort of fossil imprint left by the state of the universe just 10 nano-nano-nano-nano seconds after the Big Bang. The splotches in the Planck map represent the seeds from which the stars and galaxies formed. As is heat-map tradition, the reds and oranges signify warmer temperatures of the universe, while light and dark blues signify cooler temperatures.universe

The cooler temperatures came about because those were spots where matter was once concentrated, but with the help of gravity, collapsed to form galaxies and stars. Using the map, astronomers discovered that there is more matter clogging up the universe than we previously thought, at around 31.7%, while there’s less dark energy floating around, at around 68.3%. This shift in matter to energy ratio also indicates that the universe is expanding slower than previously though, which requires an update on its estimated age.

All told, the universe is now believed to be a healthy 13.82 billion years old. That wrinkles my brain! And also of interest is the fact that this would appear to confirm the Big Bang Theory. Though widely considered to be scientific canon, there are those who dispute this creation model of the universe and argue more complex ideas, such as the “Steady State Theory” (otherwise known as the “Theory of Continuous Creation”).

24499main_MM_Image_Feature_49_rs4In this scenario, the majority of matter in the universe was not created in a single event, but gradually by several smaller ones. What’s more, the universe will not inevitable contract back in on itself, leading to a “Big Crunch”, but will instead continue to expand until all the stars have either died out or become black holes. As Krzysztof Gorski, a member of the Planck team with JPL, put it:

This is a treasury of scientific data. We are very excited with the results. We find an early universe that is considerably less rigged and more random than other, more complex models. We think they’ll be facing a dead-end.

Martin White, a Planck project scientist with the University of California, Berkeley and the Lawrence Berkeley National Laboratory, explained further. According to White, the map shows how matter scattered throughout the universe with its associated gravity subtly bends and absorbs light, “making it wiggle to and fro.” As he went on to say:

The Planck map shows the impact of all matter back to the edge of the Universe. It’s not just a pretty picture. Our theories on how matter forms and how the Universe formed match spectacularly to this new data.

planck_satThe Planck space probe, which launched in 2009 from the Guiana Space Center in French Guiana, is a European Space Agency mission with significant contribution from NASA. The two-ton spacecraft gathers the ancient glow of the Universe’s beginning from a vantage more than a million and a half kilometers from Earth. This is not the first map produced by Planck; in 2010, it created an all-sky radiation map which scientists, using supercomputers, removed all interfering background light from to get a clear view at the deep background of the stars.

However, this is the first time any satellite has been able to picture the background radiation of the universe with such high resolution. The variation in light captured by Planck’s instruments was less than 1/100 millionth of a degree, requiring the most sensitive equipment and the contrast. So whereas cosmic radiation has appeared uniform or with only slight variations in the past, scientists are now able to see even the slightest changes, which is intrinsic to their work.planck-attnotated-580x372

So in summary, we have learned that the universe is a little older than previously expected, and that it most certainly was created in a single, chaotic event known as the Big Bang. Far from dispelling the greater mysteries, confirming these theories is really just the tip of the iceberg. There’s still the grandiose mystery of how all the fundamental laws such as gravity, nuclear forces and electromagnetism work together.

Ah, and let’s not forget the question of what transpires beneath the veil of an even horizon (aka. a Black Hole), and whether or not there is such a thing as a gateway in space and time. Finally, there’s the age old question of whether or not intelligent life exists somewhere out there, or life of any kind. But given the infinite number of stars, planets and possibilities that the universe provides, it almost surely does!

And I suppose there’s also that persistent nagging question we all wonder when we look up at the stars. Will we ever be able to get out there and take a closer look? I for one like to think so, and that it’s just a matter of time!

To boldly go!
To boldly go!

Sources: universetoday.com, (2), extremetech.com, bbc.co.uk

News From The Center of the Galaxy!

sagittarius A_flareAt least once a day, the black hole that resides at the center of the Milky Way Galaxy – aka. Sagittarius A* – shoots out an x-ray flare. These flares range in luminosity and intensity, but are usually only on the magnitude of a few dozens times its normal output. However, back in February of 2012, astronomers using the Chandra X-Ray Observatory detected the brightest flare ever observed from the central black hole, measured at 150 times its normal output.

Located some 26,000 light years from Earth, Sagittarius A* emits X-rays on a regular basis, and no one is sure why. However, a group of researchers postulated that it may be the results of asteroids or planets that wander too close to the hole and are consumed. Essentially, they believe Sagittarius A* is taking in rocky objects, eating them up, and then shooting out x-rays as exhaust.

The supermassive black hole at the center of the Milky Way galaxy.According to Michael Nowak, a research scientist at MIT Kavli and co-author of a new paper in the Astrophysical Journal, a sudden increase in consumption might explain the flare. “Suddenly, for whatever reason, Sagittarius A* is eating a lot more,” he said. “One theory is that every so often, an asteroid gets close to the black hole, the black hole stretches and rips it to pieces, and eats the material and turns it into radiation, so you see these big flares.”

This is the standard procedure that astronomers use to detect black holes – i.e. by the light energy given off as they swallow nearby matter – since they are invisible to the naked eye. Not only are black holes notorious for consuming matter, even light and gravity, the very fabric of time and space, are consumed in their maws. However, through an x-ray telescope, the centers of galaxies can appear extremely bright, giving off massive amounts of energy as they devour their surroundings. As they age, they tend to slow down, consuming less and appearing fainter.

Another MIT alumnist, Frederick K. Baganoff, has been conducting observations on Sagittarius A* with the Chandra X-ray Observatory since 2003, and in that time he has noted some interesting things. For example, he calculated that, given the amount of gas in its surroundings, Sagittarius A* should be about a million times brighter than it is — a finding that suggested the black hole throws away most of the matter they would otherwise consume.

Or as he puts it: “Everyone has this picture of black holes as vacuum sweepers, that they suck up absolutely everything. But in this really low-accretion-rate state, they’re really finicky eaters, and for some reason they actually blow away most of the energy… We’re really studying the great escape, because most of the gas escapes, and that’s not what we expect.”

The physics that underlie this process are still a mystery, but researchers like Baganoff hope to learn more through more observation. In the end, the real pay off is that it will help us to understand the history of activity at the center of our Galaxy, a history which goes back billions of years and can tell us volumes about the formation of our Milky Way and even the universe itself.

3D GIF of Rotating Nebula

click to see 3D animation

Pretty freakishly cool isn’t it? Personally, I never really got onto this GIF thing. It’s like, if it fits on the page and looks cool, it’s all good. However, this one was too cool to ignore. The brain-child of Finnish astrophotographer J-P Metsävainio, this GIF depicts IC 1396, a nebula where stars are born.

This nebula is a little over 2000 light years away, toward the constellation of Cepheus, and is well over a hundred light years across. Even at its tremendous distance, it’s wider than six full Moons in our sky. For some time, Metsävainio has been making impressive images of this nebula, but that didn’t seem to be enough for the erstwhile stargazer. And so, he began playing with 3D images in the hopes of creating a model of the structure of the nebula, one which showed it from different angles.

Granted, some have gone on record as saying this is more art than astronomy, and not all the features are one-hundred percent accurate. But the animation does give you a good sense of the nebula’s composition, as well as a glimpse of what the heart of a star-birthing nebula looks like. Notice the large blue star in the middle that is the ionizing source – i.e. the hot, young, massive star blasting out ultraviolet light which makes the nebula glow. The dark strands on the outside are filaments of dust which appear that way because absorb the visible light emitted from the center of the nebula.

The color pattern is also quite accurate, with blue on the inside and red without. This color change is due to the presence of oxygen gas within the cloud which glows blue because of its proximity to the central stars. Farther out, the starlight is too weak to make oxygen glow, so all you see is the ruddy glow from hydrogen. And fyi, that star is mu Cephei, a massive red supergiant which happens to be one of the most luminous stars in the Milky Way, possibly over 300,000 times more luminous than the Sun.

Pretty cool huh? Hat’s off to you Metsävainio. I can’t speak for everyone, but you’ve certainly blown my mind! Click on the photo to watch the animation, and if you want to download it, don’t be surprised if it takes a while. The damn thing is 7 megabytes!

Source: discovermagazine.com/badastronomy