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Universe's expansion after the Big Bang.
When Astronomers look into the night sky, they see back into time. The light from the most distant galaxies has taken billions of years to reach us. Astronomers can measure that these galaxies are hurtling away from us, as part of the Universe's expansion after the Big Bang. The more distant a Galaxy is, the more quickly it's moving away from us.
We know that the universe started from a single point billions of years ago, we know that it's expanding, and thanks to the mysterious dark energy, we know that this expansion is accelerating. In billions of years, distant galaxies will be speeding away from the Milky Way so quickly that they will recede from us faster than the speed of light. Their light will dim and fade away, and disappear from our view of the cosmos, forever inaccessible and unknowable.
And three trillion years from now, all the galaxies will have passed over the horizon, and faded from view. Future Cosmologists will know of only one galaxy: ours. The universe will appear static and unchanging, slowly cooling away. And this view will be the same from all points of view in the universe. Physicists in every Galaxy will only know of their own home, and nothing else.
This bleak view of our lonely future is all thanks to some new calculations from Lawrence Krauss from Case Western Reserve University and Robert J. Scherrer from Vanderbilt University. Their new article, called the 'The Return of the Static universe and the End of Cosmology,' was recently award a prize by the gravity Research Foundation, and will be published in the October issue of the Journal of Relativity and Gravitation.
'While physicists of the future will be able to infer that their island universe has not been eternal, it is unlikely they will be able to infer that the beginning involved a Big Bang,' report the researchers.
Another powerful tool that Astronomers use to know the universe is the cosmic microwave background radiation; the afterglow from the Big Bang. The light from these early moments of our universe has already been red shifted to longer and longer wavelengths with the expansion of the universe. What used to be visible light is now microwave radiation, and will move through the radio spectrum. Eventually the wavelengths will be so large that Astronomers will have no way to detect it.
Researchers also measure the quantities of hydrogen, helium and deuterium across the universe. Their quantities match predictions for what should have occurred in the Big Bang. For a period, the entire universe was like a giant star, converting primordial gas into heavier elements. Rapid expansion ended this period, and future elements were formed only within stars. Although the quantities of these elements match predictions today, our future Galaxy will have dispersed them and combined them so thoroughly that they'll be indiscernible as the helium produced in stars will dominate.
'Eventually, the universe will appear static,' said Krauss. 'All evidence of modern cosmology will have disappeared.'
We can only hope that research done by Cosmologists today is preserved, so future physicists can know that the true nature of the universe, and not the static place they see around them.
Evidence of Catastrophic Floods on Mars
This amazing image was captured by ESA's Mars Express spacecraft, and shows the Deuteronilus Mensae on Mars, a region shaped by glaciers millions of years ago.
The large depression in the middle of the image is approximately 2 km (1.2 miles) deep, and measures 110 km (68 miles) across. Many deep valleys cut by intense flooding feed into the region. It's believed that these valleys were caused by intense flooding from melted water ice. This water froze quickly, turning into glaciers that flowed downhill.
Although it's cold and dead now, Mars was once geologically active. It's believed that rising magma, or impact events could melt vast regions of ice, resulting in major flooding events.
Original Source: ESA News Release
Chandra's Look at the Andromeda Galaxy
NASA's Chandra X-ray Observatory took this image of the Andromeda Galaxy (aka M31), the closest major Galaxy to the Milky Way. The wider-field image is in optical, and then the zoomed in region is a composite X-ray and optical light image. The purpose of the research was to find X-ray regions and point sources in M31's central core.
The diffuse blue glow around the centre of the Galaxy comes from hot, bright gas. The bright point sources are mostly binary stars interacting with one another. In some situations, a White Dwarf is gathering material from a companion star. When too much gas piles up, an explosion occurs on the surface of the white dwarf, which Astronomers see as a flash of X-rays called a nova.
By studying these novae for a long period of time, using multiple X-ray observatories, Astronomers discovered that many of these novae last for a surprisingly short amount of time. This means that many novae were probably missed during previous observations.
One theory is that the shorter novae occur on the white dwarfs that are the highest mass, and could be ready to explode as type 1a supernovae.
Original Source: Chandra News Release
Spirit Scrapes Up Evidence of Mars' Wet Past
Although they're not so much in the news these days, the Martian rovers, Spirit and Opportunity are still hard at work on their primary mission: discovering evidence of past water on Mars. A new patch of soil uncovered by Spirit is so rich in silica, that scientists think that water must have helped concentrate it eons ago.
While it was exploring a region of hills inside Gusev crater, Spirit uncovered a patch of soil that was clearly different from the surrounding environment. Further examination by the rover's alpha particle X-ray spectrometer calculated that it was more than 90% pure silica.
This concentration of silica would have required some process involving water. One theory is that the soil might have interacted with acid vapours produced by volcanic activity in the presence of water. Another possibility is that the region might have had many hot springs.
Scientists are celebrating the Discovery as one of the most conclusive pieces of evidence for past water that the rovers have turned up so far.
Original Source: NASA/JPL News Release
What's Up this Week: May 21 - May 27, 2007
Monday, May 21 - In 1961, United States President John F. Kennedy launches the country on a journey to the Moon as he makes one of his most famous speeches to Congress: 'I believe this nation should commit itself to achieving the goal, before this decade is out, of landing a man on the Moon and returning him safely to Earth. No single space project in this period will be more impressive to mankind, or more important for the long-range exploration of space...'
Tonight let's take our own journey to the Moon as we look at a beautiful series of craters - Fabricius, Metius and Rheita.
Bordered on the south by shallow Jannsen, lunar club challenge Fabricius is a 78 kilometer diameter crater highlighted by two small interior mountain ranges. To its northeast is Metius, which is slightly larger with a diameter of 88 kilometers. Look carefully at the two. Metius has much steeper walls, while Fabricius shows differing levels and heights. Metius' smooth floor also contains a very prominent B crater on the inside of its southeast crater wall.
Further northeast is the lovely Rheita Valley which stretches almost 500 kilometers and appears more like a series of confluent craters than a fault line. 70 kilometer diameter crater Rheita is far younger than this formation because it intrudes upon it. Look for a bright point inside the crater which is its central peak.
While the Moon is still west, let's have a look at telescopic star W Virginis located about three and a half degrees southwest of Zeta (RA 13 26 01.99 Dec -03 22 43.4). This 11,000 light-year distant Cepheid type variable is oddly enough a Population II star that lies outside the galactic plane. This expanding and contracting star goes through its changes in a little over 17 days and will vary between 8th and 9th magnitude. Although it is undeniably a Cepheid, it breaks the rules by being both out of place in the cosmic scheme and displaying abnormal spectral qualities!
Tuesday, May 22 - Tonight the Moon will be our companion. Now well risen above atmospheric disturbance, this would be a great time to have a look for several lunar club challenges that you might have missed.
Most prominent of all will be two craters to the north named Atlas and Hercules. The eastern-most Atlas was named for the mythical figure which bore the weight of the world on his shoulders, and the crater spans 87 kilometers and contains a vivid Y-shaped rima in the interior basin. Western Hercules is considerably smaller at 69 kilometers in diameter and shows a deep interior crater called G. Power up and look for the tiny E crater which marks the southern crater rim. North of both is another unusual feature which many observers miss. It is a much more eroded and far older crater which only shows a basic outline and is only known as Atlas E.
Since we're here, let's take a crater walk and see how many features we can identify. Good luck and clear skies!
(1) Mare Humboldtianum, (2) Endymion, (3) Atlas, (4) Hercules, (5) Chevalier, (6) Shuckburgh, (7) Hooke, (8) Cepheus, (9) Franklin, (10) Berzelius, (11) Maury, (12) Lacus Somniorum, (13) Daniel, (14) Grove, (15) Williams, (16) Mason, (17) Plana, (18) Burg, (19) Lacus Mortis, (20) Baily, (21) Atlas E, (22) Keldysh, (23) Mare Frigoris, (24) Democritus, (25) Gartner, (26) Schwabe, (27) Thales, (28) Strabo, (29) de la Rue, (30) Hayn.
Wednesday, May 23 - Tonight no two lunar features in the north will be more prominent than Aristoteles and Eudoxus. Viewable even in small binoculars, let's take a closer look at larger Aristoteles to the north.
As a Class 1 crater, this ancient old beauty has some of the most massive walls of all lunar features. Named for the great philosopher, it stretches across 87 kilometers of lunar landscape and drops below the average surface to a depth of 366 meters - a height which is similar to Earth's tallest waterfall, the Silver Cord Cascade. While it has a few scattered interior peaks, the crater floor remains almost unscarred. As a telescopic lunar club challenge, be sure to look for a much older crater that sits on Aristoteles eastern edge. Tiny Mitchell is extremely shallow by comparison and only spans 30 kilometers. Look carefully at the formation, for although Aristoteles overlaps Mitchell, the smaller crater is actually part of the vast system of ridges which supports the larger.
Now let's have a look at Iota Virginis. While there is nothing particularly special about this spectral F type star, it does reside in a very interesting field for low power. Enjoy the colors!
Thursday, May 24 - While the Moon moves quietly towards Virgo, our first challenge for the evening will be a telescopic one on the lunar surface known as the Hadley Rille. Using our past knowledge of Mare Serenitatis, look for the break along its western shoreline that divides the Caucasus and Apennine mountain ranges. Just south of this break is the bright peak of Mons Hadley. You'll find this area of highest interest for several reasons, so power up as much as possible.
Impressive Mons Hadley measures about 24 by 48 kilometers at its base and reaches up an incredible 4572 meters. If this mountain was indeed caused by volcanic activity on the lunar surface, this would make it comparable to some of the very highest volcanically caused peaks on Earth, such as Mount Shasta or Mount Rainer. To its south is the secondary peak Mons Hadley Delta - the home of the Apollo 15 landing site just a breath north of where it extends into the cove created by Palus Putredinus.
Along this ridgeline and smooth floor, look for a major fault line known as the Hadley Rille, winding its way across 120 kilometers of lunar surface. In places, the rille spans 1500 meters in width and drops to a depth of 300 meters below the surface. Believed to have been formed by volcanic activity some 3.3 billion years ago, we can see the impact that lower gravity has had on this type of formation, since earthly lava channels are less than 10 kilometers long and only around 100 meters wide.
During the Apollo 15 mission, Hadley Rille was visited at a point where it was only 1.6 kilometers wide - still a considerable distance as seen in respect to astronaut James Irwin and the lunar rover. Over a period of time, its lava may have continued to flow through this area, yet it remains forever buried beneath years of regolith.
Friday, May 25 - Tonight on the Moon we'll be looking for another challenging feature and a crater which conjoins it - Stofler and Faraday.
Located along the terminator to the south, crater Stofler was named for Dutch mathematician and Astronomer Johan Stofler. Consuming lunar landscape with an immense diameter of 126 kilometers and dropping 2760 meters below the surface, Stofler is a wonderland of small details in an eroded surrounding. Breaking its wall on the north is Fernelius, but sharing the southeast boundary is Faraday.
Named for English physicist and chemist Michael Faraday, it is more complex and deeper at 4090 meters, but far smaller at 70 kilometers in diameter. Look for myriad smaller strikes which bind the two together!
When you're done, let's have a look at another delightful pair that's joined together - Gamma Virginis...
Better known as Porrima, this is one cool binary with almost equal spectral types and brightnesses. Discovered by Bradley and Pound in 1718, John Herschel was the first to predict this pair's orbit in 1833 and state that one day they would become inseparable to all but the very largest of telescopes - and he was right. In 1920 the A and B stars had reached their maximum separation, and during 2007 they will be as close together as they will ever be. Observed as a single star in 1836 by William Herschel, its 171 year periastron will put Porrima in the exact position now as it was when Sir William saw it!
Saturday, May 26 - Are you ready to explore some more history? Then tonight have a look at the Moon and identify Alphonsus - it's the centermost in a line of rings which looks much like the Theophilus, Cyrillus and Catharina trio.
Alphonsus is a very old, Class V crater which spans 118 kilometers in diameter and drops below the surface by about 2730 meters and contains a small central peak. Partially flooded, Eugene Shoemaker had made of study of this crater's formation and found dark haloes on the floor. Again, this could be attributed to volcanism and Shoemaker believed them to be maar volcanoes, and the haloes to be dark ash. Power up and look closely at the central peak, for not only did Ranger 9 hard land just northeast, but this is the only area on the Moon where an Astronomer has observed a change and back up that observation with photographic proof.
On November 2, 1958 Nikolai Kozyrev's long and arduous study of Alphonsus was about to be rewarded. Some two years earlier Dinsmore Alter had taken a series of photographs from the Mt. Wilson 60? reflector that showed hazy patches in this area that could not be accounted for. Night after night, Kozyrev continued to study at the Crimean Observatory - but with no success. During the process of guiding the scope for a spectrogram the unbelievable happened - a cloud of gas containing carbon molecules had been captured!
Selected as the last target for the Ranger photographic mission series, Alphonsus delivered 5814 spectacular high-resolution images of this mysterious region before Ranger 9 splattered nearby.
Capture it yourself tonight!
Sunday, May 27 - As we begin the evening, let's have a look at awesome crater Clavius. As a huge mountain-walled plain, Clavius will appear near the terminator tonight in the lunar southern hemisphere, rivaled only in sheer size by similar structured Deslandres and Baily. Rising 1646 meters above the surface, the interior wall slopes gently downward for a distance of almost 24 km and a span of 225 km. Its crater-strewn walls are over 56 km thick!
Clavius is punctuated by many pockmarks and craters; the largest on the southeast wall is named Rutherford. Its twin, Porter, lies to the northeast. Long noted as a test of optics, Clavius crater can offer up to thirteen such small craters on a steady night at high power. How many can you see?
If you want to continue with tests of resolution, why not visit nearby Theta Virginis? It might be close to the Moon, but it's 415 light-years away from Earth! The primary star is a white A-type subgiant, but it's also a spectroscopic binary of two companions which orbit each other about every 14 years. In turn, this is orbited by a 9th magnitude F-type star which is a close 7.1 arc-seconds away from the primary. Look for the fourth member of the Theta Virginis system well away at 70 arc-seconds, but shining at a feeble magnitude 10.4.
Astrosphere for May 22, 2007
Once again, let's see what's happening around the astrosphere.
First, I'd like to remind you that I'll be hosting the 4th Carnival of Space here at universe Today. Write a space-related story, submit it to me, and I'll link to it from the Carnival. You'll get lots of new readers coming to your blog. Here's a link to the instructions on how to participate.
There's a bit of a frenzy going on with a certain presidential candidate's blog. Apparently, somebody doesn't think the Sun is the centre of the Solar System. Both astropixie and Cocktail Party Physics have the scoop on this.
Vern's Weblog has another list of things you can see in the night sky this week, as well as a few pictures captured through his telescope.
Astroblog has a nice picture of the Moon and Venus together in the sky.
Remember when I mentioned that May 19 was International Sidewalk astronomy night? Top of the Lawn blog has a report of how the night went in New York City.
Did an exploding comet wipe out the large mammals of North America 13,000 years ago? Skymania News has a story on this interesting research.
International Sidewalk Astronomy Night - May 19, 2007
I'm sorry this is such late notice, nobody let me know this was happening. Although sidewalk Astronomers have been hitting the streets in the US for years, Saturday, May 19, 2007 is going to be the first International Sidewalk astronomy Night.
If you've never heard of Sidewalk Astronomy, it's an absolutely ingenious idea founded by John Dobson - inventor of the Dobsonian telescope. Amateur Astronomers take their trusty telescopes out to public locations, like parks and busy streets, and give the general public a chance to see some of the most spectacular objects. They time the events so that major planets, the Moon, etc are visible in the early evening; objects visible from light polluted skies.
And this year, that evening is May 19.
Unlike previous years, the event is going international. Amateur Astronomers will be setting up their scopes across the entire planet, from San Francisco to Sao Paulo to Kharkov. The event organizers are hoping to get 1,000 telescopes set up across the planet, engaging the public in astronomy.
If you're an amateur astronomer, and want to help out, or if you want to find out where an event is happening near you so you can check out what they have to offer, visit their site here.
Sensitive Gemini Instrument Damaged
A key scientific instrument attached to the Gemini South observatory was damaged in late April when a malfunctioning heater raised its temperature to 200-degrees Celsius. It was never meant to withstand temperatures this high, and will be out of commission for several months while technicians make repairs.
The device is called Gemini Near Infrared Spectrometer (GNIRS), and it measures the spectrum of light coming from a distant object, to help Astronomers understand its composition.
On the weekend of April 20th, technicians were using a system that warms up the instrument between observations, and it was left running for several days. This is standard procedure; however, an independent controller that shuts off power to the heater failed, and allowed the heater to reach 200-degrees.
Once they realized the instrument was being cooked by the heater, the technicians shut it down and allowed it to cool for a few days. They removed the instrument from the telescope, and dismantled it to access the damage.
Unfortunately, portions of GNIRS were damaged, and the CCD science detector was completely destroyed. Most of the instrument is undamaged, but it will still take several months to examine each component, clean and replace the damaged ones, and retest it for astronomical duty.
Original Source: Gemini News Release
Spitzer Shows Young Stars Hatching in Orion
The latest image released from the Spitzer Space Telescope shows infant stars 'hatching' in the head of Orion. Astronomers think that a supernova 3 million years ago sent shockwaves through the region, collapsing clouds of gas and dust, and beginning a new generation of star formation.
The region imaged by Spitzer is called Barnard 30, located about 1,300 light-years from Earth in the constellation of Orion. More specifically, it's located right beside the star considered to be Orion's head, lambda Orionis.
Since the region is shrouded in dark clouds of gas and dust that obscure visible light images, this was an ideal target for Spitzer, which can peer right through them in the infrared spectrum. The tints of orange-red glow are dust particles warmed by the newly forming stars. The reddish-pink dots are the young stars themselves, embedded in the clouds of gas and dust.
Original Source: Spitzer News Release
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