Space and astronomy news
Returning to our tour of the solar system, let’s voyage away from the largest planet to the second largest, Saturn. Once again, we’ll break up our visit because there’s lots to talk about. This week, we talk about Saturn and its famous rings. Next week, we’ll discuss its many moons.
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Saturn – Show notes and transcript
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NASA announced today that the space shuttle Discovery has been officially targeted for an October 23rd launch. If all goes well, the shuttle will blast off from Florida’s Cape Canaveral at 11:38 a.m. EDT, carrying 7 astronauts into space to meet up with the International Space Station – mission STS-120 will be on its way.
There was a slight safety concern that might have held back the launch. NASA’s Engineering and Safety Center had raised awareness that there might be a problem with the reinforced carbon on three of Discovery’s wing leading edge panels. Agency officials met to discuss the situation, and decided that the panels didn’t need to be replaced before the mission.
During their 14 days in space, the shuttle crew will install the new Harmony module onto the International Space Station. This will serve as a hub for future international laboratories.
The crew will have their work cut out for them, though. They’re scheduled to make 4 spacewalks, and the station crew will complete one as well.
Discovery is expected to return back to Earth on November 6th.
Original Source: NASA Shuttle News
Black holes come in two varieties: supermassive and stellar. The supermassive variety can have millions of times
the mass of a star, while the stellar varieties are usually just a few times the mass of a single sun. Using the Chandra X-Ray Observatory, astronomers have turned up the most massive stellar mass black hole ever seen, weighing in at 15.7 times the mass of the Sun, lurking in a nearby galaxy.
M33 is a relatively nearby galaxy, located only 3 million light years from Earth. This newly discovered black hole has been designated as M33 X-7.
Astronomers using NASA’s Chandra X-Ray Observatory and the Gemini telescope on Mauna Kea were able to precisely determine the black hole’s mass because it’s actually in a binary system. Its binary partner is unusual too; a star with 70 times the mass of the Sun.
M33 X-7 orbits its companion star every 3.5 days, briefly passing behind it. This blocks the torrent of X-rays streaming from the environment around the black hole, so that astronomers were able to calculate its orbit. Once they could calculate the orbits of the two binary objects, it’s relatively straightforward to calculate their respective masses.
The fate of the companion star will eventually match its partner. “This is a huge star that is partnered with a huge black hole,” said coauthor Jeffrey McClintock of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass. “Eventually, the companion will also go supernova and then we’ll have a pair of black holes.”
Although the black hole has less mass today, it must have started out with more. With more mass in the original star, it would have consumed its fuel more quickly, and detonated as a supernova earlier.
Here’s a puzzle, though. Before the black hole formed, the two stars wouldn’t have been able to orbit so closely. In fact, they would have been orbiting inside each other. This means that they were once further apart, and the process of sharing their outer atmospheres brought their orbits closer together.
Original Source: Chandra News Release
NASA originally expected they’d only last a few months, but the plucky Martian rovers are still crawling across the surface of Mars – more than 3 years later. So the agency has gone ahead and extended their missions… again. This is the fifth time NASA has extended their mission, keeping them operational potentially through 2009.
The twin rovers landed on the surface of Mars in January, 2004. Mission planners expected that it would only take a few months before dust coated the rovers’ solar panels so thickly that they wouldn’t be able to generate power any more. But the Martian weather had a trick; dust devils and wind gusts came by often enough to keep the solar panels relatively clear of dust. Without the loss of power looming, the rovers have been able to keep going, and going, and going.
Their accomplishments to date have been staggering. So far, Spirit has driven a total of 7.26 kilometers (4.51 miles) and has returned more than 102,000 images. Opportunity has driven 11.57 kilometers (7.19 miles) and has returned more than 94,000 images.
Opportunity turned up evidence of the planet’s watery past, when oceans affected rocks for long periods of time, and deposited layers of material. Spirit also found that water altered the mineral composition of the rocks and soil in its surroundings. The rovers have been instrumental in helping scientists understand the Martian dust devils. And both have discovered metallic meteorites sitting the surface of the Red Planet. One of these has a similar composition to the meteorite that reached Earth from Mars.
Original Source: NASA/JPL News Release
Seen one Martian crater and you’ve seen them all right? Well, check this one out. It’s an image of Maunder Crater on the surface of Mars, captured by ESA’s Mars Express. Although the crater is large, 90 km (56 miles) across, it’s very shallow – less than a kilometre. It used to be much deeper, but some geologic process has since filled it in.
The images of Maunder crater were captured in late 2005 by Mars Express at a resolution of roughly 15 metres per pixel. The crater, named after British astronomer Edward W. Maunder, is located about halfway between Argyre Planitia and Hellas Planitia on the southern Highlands of Mars.
It once looked like a more traditional crater, but then something happened on the west side to make it cave in. A large landslide pushed material from the crater wall to the inner portion. The edges of the crater that remain show gullies that could have been created when large amounts of material was flowing down into the crater.
One intriguing discovery: there are gullies along the upper side of the trough in the middle of the crater that have been caused by seeping water.
Original Source: ESA News Release
Look at the picture associated with this story. It just looks like a pretty galaxy, right? Well, according to astronomers, it’s actually much older than it appears. This image, captured by the Hubble Space Telescope, provides one of the most detailed observations ever taken of I Zwicky 18 – a galaxy that looks younger than it should.
According to researcher, galaxies like I Zwicky 18 are much more common billions of light years away, at a time when the Universe was much younger than it is today. These baby galaxies still had large quantities of gas and dust they could use up to make new stars. Their young hot stars, composed largely of primordial hydrogen and helium manufactured during the Big Bang, burn brightly in the blue end of the visible light spectrum.
Older galaxies, like our own Milky Way have had plenty of time to use up those primordial elements, mixing in heavier elements with generation after generation of supernovae.
Astronomers used to think that I Zwicky 18 was a rare example of a nearby, newly forming galaxy. Located only 59 million light-years from Earth, this galaxy could be used as a sort of time machine, to see the stages that galaxies went through early on in their evolution.
Well, the new observations from Hubble have dashed those hopes. I Zwicky 18 is old, possibly as old as the Milky Way, forming its first stars up to 10 billion years ago. With its sensitive instruments, Hubble was able to spot previously hidden red, older stars, showing that the galaxy has been forming stars for billions of years.
So how is it possible that such an old galaxy still has large quantities of primordial hydrogen and helium, but we see rapid star formation today? It’s possible that the galaxy has just been going slowly, forming stars at a dramatically reduced rate in the past. But something kicked that rate of star formation into high gear in the recent past.
Original Source: Hubble News Release
For the photo, we’ve got this wonderful image of M31 (the Andromeda Galaxy) by John Chumack.
Now, before we get rolling with today’s episode, I’d like to encourage you to subscribe to Universe Today. Instead of coming here regularly, just subscribe so you find out when I’ve updated the site, automagically. There are two ways – both free, of course – to do this. One is to subscribe to the email subscription. Just put your email into the box on the right there, and you’ll get the latest stories by email every day. The second way is with a feed reader, such as Google Reader. Set up a Google Reader account, and then subscribe to the Universe Today feed. Here’s the URL: http://www.universetoday.com/universetoday.xml.
Once you get your news through a feed, you’ll never go back.
Centauri Dreams considers the controversy of whether we should try and signal extraterrestrial civilizations.
Now all your work on the Galaxy Zoo is starting to pay off. The Universe might be lopsided.
The Bad Astronomer explains how valuable contributions to astronomy come from amateurs.
We’re just 5 days away from the Space Elevator Games. I sure wish I could attend them.
The astropixie suggests you try and spot Mercury this week. It’s not an easy challenge.
Scientific American’s blog has posted computer desktop images of Iapetus, in a variety of convenient sizes.
Do you have a space-related blog? Email me your URL, and I’ll start watching you. Write something interesting, and I’ll link to it.
We interrupt this tour through the Solar System to bring you a special show to deal with one of our most complicated subjects: the Big Bang. Specifically, how it’s possible that the universe could have expanded faster than the speed of light. The theory is called the inflationary theory, and the evidence is mounting to support it. Einstein said that nothing can move faster than the speed of light, and yet astronomers think the universe expanded from a microscopic spec to become larger than the solar system, in a fraction of a second.
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Inflation – Show notes and transcript
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Monday, October 15 – As the evening begins, be sure to at least walk out and look at the Moon. For many observers, bright red Antares will be only around a half degree north of the waxing crescent. Of course, you know that a brush this close could mean an occultation for your area! Be sure to check IOTA for visibility locations and times. No special equipment is needed to check out a lunar occultation, but thanks to an historic observation of just such an event, Antares’ companion star was discovered by Professor Johannes Burg in Vienna on April 13, 1819!
Today in 1963 marks the first detection of an interstellar molecule. This discovery was made by Sander Weinreb (with Barrett, Meeks, and Henry) on the MIT Millstone Hill 84-foot dish. The discovery was made possible by new correlation receiver technology, and picked up a hydroxyl molecule in an absorption band. By using the radio galaxy Cas A as a background continuum source, the detection occurred at 1667.46 MHz and again at 1665.34 MHz. By the dawn of 2000, nearly 200 different interstellar molecules had been identified and many of these are classified as organic.
Tonight let’s have a look at a radio source as we visit a pulsar located almost mid-way between Theta and Beta Capricorni – PSR2045+16.
While pulsars aren’t truly visible objects, there is still something undeniably cool about locating the field in which a rotating neutron star is sending out staccato pulses of radio waves anywhere between .001 and 4 seconds apart. If you have bright star 19 in the binocular field, then you know you’re in the right area for many radio sources, including many nearby quasars… Just imagine the possibilities!
Tuesday, October 16 – Do you remember Professor Burg who discovered Antares’ companion during an occultation? Then tonight let’s have a look at the crater named for him as we begin by using past study crater Posidonius as our guide.
If you walk along the terminator to the northwest, you’ll see the punctuation of 40 kilometer-wide Burg just emerging from the shadows. While it doesn’t appear to be a grand crater like Posidonius, it has a redeeming feature: it’s deep – real deep. If Burg were filled with water here on Earth, it would require a deep submergence vehicle like ALVIN to reach its 3680 meter floor! This class II crater stands fairly alone on an expanse of lunarscape known as Lacus Mortis. If the terminator has advanced enough at your time of viewing, you may be able to see this walled plain’s western boundary peeking out of the shadows.
Now let’s drop south-southeast of Beta Capricorni to have a look at a pair of doubles – Rho and Pi.
Northernmost Pi is a multiple system slightly less than 100 light-years away, with each discernable member also being a spectroscopic double. Separated by about an eighth of a light-year, look for a 5th magnitude yellow/white giant with a very close 9th magnitude companion. Further south is Pi, a triple star system which has a traditional name – Okul. Located around 670 light-years away, look for a bright blue/white 5th magnitude primary that is also a spectroscopic double – and its much easier C component, which is around magnitude 8.
Wednesday, October 17 – Tonight let’s start with the Moon and explore a binocular curiosity.
Look on the northeast shore of Mare Serenitatis for the bright ring of Posidonius, which contains several equally bright points both around and within it. Now look at Mare Crisium and get a feel for its size. A little more than one Crisium’s length west of Posidonius you’ll meet Aristotle and Eudoxus. Drop a similar length south and you will be at the tiny, bright crater Linne on the expanse of Mare Serenitatis. So what’s so cool about this little white dot? With only binoculars you are resolving a crater that is one mile wide, in a seven mile wide patch of bright ejecta from close to a quarter of a million miles away!
Now point those binoculars towards the northwestern corner of Capricornus and have a look a spectacular Alpha!
Although the Alpha 1 and 2 pairing is strictly a visual binary, that won’t stop you from enjoying their slightly yellow and orange colors. Collectively they are named Al Giedi, and the brighter of the pair is Alpha 2 at about 100 light-years distant; while Alpha 1 is around five times further away. Now power up with a telescope and you’ll find that both stars are also visual doubles! While the companion stars to both are around the same magnitude, you’ll find that Alpha 2 is separated by three times as much distance. Be sure to mark your observation lists and enjoy!
Thursday, October 18 – Today in 1959, Soviet Luna 3 began returning the first photographs of the Moon’s far side. Also today – but in 1967 – the Soviets again made history as Venera 4 became the first spacecraft to probe Venus’ atmosphere. If you’re up before dawn, be sure to have a look at brilliant Venus pairing with the solemn Saturn. You’ll find them just a few fingerwidths apart!
Tonight let’s walk on the Moon and check off a few more features on your lunar list! Look for the prominent pair of Aristillus and Autolycus caught just east of the Apennine Mountain range. If you haven’t logged the shallow Archimedes, tonight is your chance. Take the time to closely inspect the differing lava flow patterns on the floor of Palus Putredinus – and you can’t miss the bright ring of Manilius!
When we’re done? Let’s go have a look at Gamma Aquilae just for the heck of it. Just northwest of bright Altair, Gamma has the very cool name of Tarazed and is believed to be over 300 light-years away. This K3 type giant will show just a slightly yellow coloration – but what really makes this one special is the low power field!
Friday, October 19 – Our lunar mission for tonight is to move south past the crater rings of Ptolemaeus, Alphonsus, Arzachel and Purbach until we end up at the spectacular crater Walter. Named for Dutch astronomer Bernhard Walter, this 132 by 140 kilometer-wide lunar feature offers up amazing details at high power. Perhaps amongst the most fascinating is to take the time to study the differing levels, which drop to a maximum of 4130 meters below the surface. Multiple interior strikes abound, but the most fascinating of all is the wall crater Nonius. Spanning 70 kilometers, Nonius would also appear to have a double strike of its own – one that’s 2990 meters deep!
Now, let’s go have a look at the northeastern corner of Capricornus as we learn about Delta…
Its proper name is Deneb Algedi and this nearly 3rd magnitude star is a stunning blue/ white. Curiously enough, it’s a rather close star – only about 50 light-years from Earth. Hovering so close to it that we cannot even correctly assess its spectral type is a binary companion whose eclipsing orbit causes Delta to be a very slight variable – with a period of just about one day. In its own way, Delta is rather historic… For it was only 4 degrees north of this star that Uranus was first sighted by Galle in 1846!
Saturday, October 20 – It’s bold. It’s beautiful. You’ve looked at it hundreds of times…and tonight? It’s Copernicus…
While Copernicus is not the oldest, deepest, largest, or brightest crater on the Moon, it certainly is one of the most detailed. Visible in binoculars toward Plato and near the terminator, this youthful crater gives a highly etched appearance. Its location in a fairly smooth plain near the center of the Moon’s disc, and its prominent “splash” ray system, all combine to make Copernicus visually stunning in a small telescope.
Spanning 100 kilometers in diameter, with 23 kilometer thick walls, the “Mighty One” is most definitely an impact crater that left its impression down to 3840 meters below the surface. Geologist Gene Shoemaker cited many features of Copernicus which mirror our own terrestrial impact features. Many of these Copernican features could have been caused by a large meteoritic body…a body about the size of Comet Halley’s nucleus. No matter what optical aid you use, mid-placed Copernicus simply rocks!
Now we are slipping into the stream of Comet Halley and into one of the finest meteor showers of the year. If skies are clear tonight, this would be the perfect chance to begin your observations of the Orionid meteor shower. But go to bed early… And wait for the Moon to set!
Sunday, October 21 – Be sure to be outdoors before dawn to enjoy one of the year’s most reliable meteor showers. The offspring of Comet Halley will grace the early morning hours as they return once again as the Orionid meteor shower. This dependable shower produces an average of 10-20 meteors per hour at maximum and the best activity begins before local midnight on the 20th, and reaches its best as Orion stands high to the south at about two hours before local dawn on the 21st. With the Moon nearly out of the picture, this is gonna be great!
Although Comet Halley has long since departed our Solar System, the debris left from its trail still remain scattered in Earth’s orbital path around the Sun, allowing us to predict when this meteor shower will occur. We first enter the “stream” at the beginning of October and do not leave it until the beginning of November, making your chances of “catching a falling star” even greater! These meteors are very fast, and although they are faint, it is still possible to see an occasional fireball that leaves a persistent trail.
For best success, try to get away from city lights. Facing south-southeast, simply relax and enjoy the stars of the winter Milky Way. The radiant, or apparent point of origin, for this shower will be near the red giant Alpha Orionis (Betelguese), but meteors may occur from any point in the sky. You will make your meteor watching experience much more comfortable if you take along a lawn chair, a blanket and a thermos of your favorite beverage.
Clouded out? Don’t despair. You don’t always need your eyes or perfect weather to meteor watch. By tuning an FM radio to the lowest frequency possible that does not receive a clear signal, you can practice radio meteor listening! An outdoor FM antenna pointed at the zenith and connected to your receiver will increase your chances, but it’s not necessary. Simply turn up the static and listen. Those hums, whistles, beeps, bongs, and occasional snatches of signals are our own radio signals being reflected off the meteor’s ion trail!
Pretty cool, huh?
We’re rapidly approaching Mars, so it’s only appropriate to make that the astrophoto of the day. This image was captured by Kyle Edwards.
First, let me draw your attention to the Carnival of Space. This week it’s being held at Space for Commerce. No entry from me this week. I really need to get more organized about that.
From HobbySpace we learn that NASA is restarting its suborbital rocket and balloon programs. These are surprisingly cost-effective ways to gather science.
Remember that X-Wing model that came apart on launch? Here’s a theory about what might have brought it down.
Look out Moon, here comes another mission. This time, from China.
When Cassini’s mission comes to an end, it’ll probably be dropped down into Saturn to gather some final science. If you think the loonies are going to predict that this will somehow ignite Saturn, you don’t need to wait. They already think this.