Saturday, May 21, 2011

Saturday Space News!

Another Saturday with a couple more news stories! I hope you all are having a great weekend. We're having our 'horse party' for the Preakness race here in Maryland today. So it's a good day to relax, sip on something cool, and enjoy the Universe. And once again, it appears the Rapture has disappointed.

So in astronomy news this past week, there are a couple of stories of interest:

First up, NASA set the launch date for the final space shuttle flight. Space Shuttle Atlantis is targeted to lift off on July 8 around 11:40 AM EDT from Kennedy Space Center in Florida. The shuttle will take four veteran astronauts to deliver supplies and spare parts to the International Space Station. It will also deliver experimental equipment to test robotically refuel and service satellites in space. Given the shuttles recent history, this launch date can be expected to be delayed.

Illustration showing that dark energy (represented by purple grid) is a smooth, uniform force that now dominates over the effects of gravity (green grid). (Credit: NASA/JPL-Caltech)

Next, Astronomers now have a better understanding of Dark Energy and Gravity. A survey of 200,000 galaxies confirms that dark energy is driving the Universe apart at accelerating speeds. The survey, GALEX, used data from NASA’s space-based Galaxy Evolution Explorer and the Anglo-Australian Telescope on Siding Spring Mountain in Australia. The force is seen to be constant and uniform across the Universe. Dark energy is thought to dominate the Universe, making up about 74 percent of it, though what drives and the actual nature of dark energy is still poorly understood. (Additional source)

Astronomers have discovered a new class of planet. The 10 discovered planets are all free-floating, not orbiting a star, and about the size of Jupiter. These 'orphan planets' are about 10,000 to 20,000 light-years from Earth and indicate that a wide-range of these planets exist, perhaps more common than stars. There are expected to be hundreds of billions in the Milky Way, ranging across all sizes, including Earth-sized ones. The ones detected are at the limit of current technology, the smallest possible objects they could detect, using gravitational lensing techniques. The planets initially form around stars, and become orphaned due to gravitational interactions with other planets that force them out of the system. Smaller planets would be easier to influence, making it likely that small planets are more numerous in interstellar space then these large ones. It is even possible that our solar system has lost a planet or two due to this process. A lost brother out in space, as it were.

Voyager 2 (Credit: NASA)

Not really news, but still pretty awesome. You can follow the Voyager 2 space probe on Twitter. It provides real time updates of the probe and its sister, Voyager 1, of their distance from the Earth, chronicling their journey into interstellar space. (As of their last update, Voyager 2 is 13 hrs 08 mins 50 secs of light-travel time from Earth and Voyager 1 is 16 hrs 06 mins 58 secs)

And this one isn't even really astronomy related, but my friend Leroy, who I've mentioned before, is going on a cross country adventure. He is chronicling his adventure in blog format, and although he hasn't posted anything yet, it should be work checking out: The Life and Times of a Modern Day Gypsy.

Bella, wishing her the best.
In a bit of sad personal news, our cat Bella is in the animal hospital. She's been having a rough last couple of days. She's about 14 years old, don't really remember for sure, so shes lived a pretty long life. It's just pretty sad that we might be losing my favorite cat in the next day or two. Maybe she will pull through, but the amount of health complications she's having doesn't make me optimistic. At least I got her to purr for me before they took her to the vet, if that was the last time I get to see her.

Thursday, May 19, 2011

Astro-Lesson: Supernova

This week is going to be about one of the most massive explosions in the Universe: Supernova. Last week, when discussion the star life cycle, I had mentioned supernovae* briefly as an outcome of the death of super massive stars. But that is only one kind of supernova, there happens to be two types which are further subdivided.
 *The plural of supernova is supernovae.

So, get ready to learn a little bit about supernovae and some see some awesome pictures.

The Crab Nebula, the remnant of a supernova recorded by Chinese astronomers in 1054. (Credit: NASA)

A supernova is an extremely luminous explosion of a star with a burst of radiation that often briefly outshines the entire galaxy in which the star resides. It can take several weeks or months for a supernova to fade, over this time it can emit as much energy as the Sun over its whole life span. The explosion expels most, if not all, of a star's matter into space, creating a shock wave. The shock wave sweeps up dust and gas from the star an the interstellar medium, creating at supernova remnant. These remnants are usually what you see in images from the Hubble Space Telescope and other telescopes.

Supernova 1994D (the bright 'star' on the bottom left) in Galaxy NGC 4526. (Credit: HST/NASA/ESA)

The word nova means "new" in Latin, referring to what appears to be a bright new star in the night sky. Occasionally these explosions cause what appears to be a new star in the sky. The prefix 'super-' separates a supernova from an ordinary nova, which also involve a star increasing in brightness, though to a lesser extent and through a different mechanism.
Types of Supernova: there are two basic types of supernova, and a couple of other distinctions:

Illustration of different ways a supernova is formed. (Source)

Type Ia: These result from some binary star systems in which a white dwarf absorbs matter from a companion. (What kind of companion star is best suited to produce Type Ia supernovae is hotly debated.) The idea is that so much mass piles up on the white dwarf that its core reaches a critical density that results in an uncontrolled fusion of carbon and oxygen, thus detonating the star.

Type Ib and Ic: These ones look similar to Type Ia when looking at their spectrum, but are distinguished because they lack certain different lines of spectra. The lack of spectra means that elements in the core may have been lost due to other means, and in general Type Ib/c may be referred to as stripped core-collapse supernovae. These types of supernova are also incredibly rare, and their sources might also be the progenitors of gamma ray bursts.

The onion like layers of a star's core before going supernova.

Type II: A common supernova type, usually found in the spiral arms of galaxies and not in elliptical galaxies, they are distinguished by the presence of hydrogen in their spectrum. These are known to be caused by the rapid collapse and violent explosion of a massive star. There exists several subcategories of Type II supernova, including II-L, which has a steady, linear decline in light over time; II-P which has a slower decline (a plateau) followed by normal decay; IIn, the "n" denotes narrow, which have narrow hydrogen emission lines in their spectrum (probably caused by blue variable stars); and IIb, which initially resembles a Type II supernova but later has a spectrum resembling Type Ib.

A different image of the Crab Nebula, a composite image of the radiation in the nebula's core region. A pulsar (a type of neutron star) can be seen near the center, pushing out jets of particles. (Credit: NASA/HST/CXC/ASU/J. Hester et al.)

Those are the general types of supernova known to astronomers. After the explosion the cores are left behind and usually create a neutron star or a black hole. Supernova are pretty rare events in a galaxies, the Milky Way experiences one about every 50 years, though the last one seen from Earth was in 1604. This last one was known as Kepler's Star and was easily visible in the night sky, brighter then all the planets except Venus. It was visible during the day for over 3 weeks.

False-color of the remnant of SN 1604 (Kepler's Star). (Credit: HST/NASA/ESA)

There are several large candidates in the Milky Way that might go supernova in the next million years, these stars include VY Canis Majoris, Betelgeuse, and Eta Carinae. Once these stars explode, they will provide a vital part in stellar evolution. Supernova explosions are the source of many heavy elements including uranium and plutonium. All of these elements get shot out into space and form clouds of dust that eventually condense and form new stars, or the shock wave can trigger star formation in an already present cloud. This is likely the cause of formation for our own star. This includes the Earth and us. We owe our existence to these violent explosions, the death of a star. As Carl Sagan would say, "We're made of star stuff."

Thanks for reading! This was my 100th post on this blog. It hardly seems like it, I only started back in February. I really have enjoyed writing these posts for my readers, and I enjoy the feedback. I hope you have learned some new things about astronomy from what I've written, or at least enjoy the pictures. I think supernovae are a good way to celebrate. Thank again for reading and I plan to continue this for as long as I can.

Tuesday, May 17, 2011

Changing Things Up.

So, my schedule has changed around and I don't think I will be posting the Astro-Lessons on Tuesday afternoon anymore. Mostly this is because I play Frisbee with a bunch of friends.

We had been playing on Thursdays, but Tuesdays seem to be working out better. Unfortunately, I used to spend most of my Tuesday putting together a good Astro-Lesson, but this week I just didn't have the time and no idea what to write really pulled at me.

So, I am thinking of moving the Astro-Lesson topics to Wednesday afternoon. And I have a good idea what I want to write for the next one. I'll also be bringing the poll back, it was just easier to do the last few ones without it. I felt that the star life cycle was a natural progression after the Sun. And tomorrow, to continue on that, I am going to do supernovae. It will also be my 100th post, so I figure I'll celebrate with a BANG!

In addition to that, for the rest of the week, I might only be posting every other day or so. It's going to be pretty busy with our party this weekend. Once again, the real world takes precedence over blogging, but I am totally excited.

No new astronomy or science-y stuff from me today! But if you really want to learn something, I suggest reading this NASA article on the Alpha Magnetic Spectrometer that Space Shuttle Endeavour is delivering to the International Space Station. I know some people have asked questions about it, what it is, and what it does:

Monday, May 16, 2011

Successful Endeavour Launch

Space Shuttle Endeavour successfully lifted off into space this morning from Kennedy Space Center in Florida. This is the shuttle's final mission (STS-134), led by mission commander Mark Kelly. The crew will be delivering the Alpha Magnetic Spectrometer to the International Space Station, among other science projects and spare parts.

You can watch the launch below (I attempted to embed the code from NASA's website, if it doesn't work, watch it here):

After nearly a month long delay due to a heater malfunction, the launch went flawlessly. Endeavour is the youngest of the shuttles, built to replace the Challenger, which was tragically lost in a 1986 launch accident. Endeavour saw it's first flight in 1992, almost exactly 19 years ago. After almost two decades of service, the heater malfunction shows Endeavour age and the need for replacements. The other shuttles have been in service for over 30 years.

After Endeavour's final 16-day mission is complete, the shuttle will be cleaned and prepared for public display at the California Science Center, a museum in Los Angeles. The final planned shuttle mission will be STS-135, the final voyage of Atlantis, scheduled for mid-July.

Sunday, May 15, 2011

Impending End of the World

So as you may or may not have heard, apparently Judgement Day is coming this weekend. According to some loonies, the Rapture is going to occur on May 21, 2011. This Saturday.

'Borrowed' from My Own Private Idaho.

Unfortunately they don't give a time, which kind of worries me. I hope it happens at 11:59 PM or something like that. See, Maryland is home to the Preakness, the second race of the Triple Crown (the Kentucky Derby is the first). It also happens to be this Saturday afternoon, which I think is a conflict of interests, as God will be swamped with prayers for Animal Kingdom, Dialed In, Astrology, Midnight Interlude, Mucho Macho Man, and other greatly named horses. And how can he not let a horse name Norman Asbjornson win?

This is 136th Running of the Race

Anyways, this event isn't just about the horses, it has turned into a reason to drink and celebrate the warmer days, like a pre-Memorial Day weekend party. My parents are having a party at their house, which I'm pretty excited about. There will be friends, family, and booze! With plenty of Black-Eyed Susans, the official mixed drink of the race.

A Black-Eyed Susan- Flower, Drink, or a Very Unfortunately Girl.

I also think that the Rapture is kinda boring. It's been claimed to come so many times, it's now like the boy who cried wolf. People always say the end of the world is coming, but there is nothing to it but trying to get people's attention. Not to mention that the guy who made this 'prediction' has failed every other time he has tried to do this. Why do people keep listening to him? Doesn't we know that the Mayans have several centuries on him, and are clearly more accurate? 2012 seems like a much more convenient doomsday for me.

I think the Mayan's would be upset after all the work put into their snazzy calendar.

The fact is that there is NOTHING to worry about. Life will go on, I'm pretty sure most people will ignore this. There is no reason to fear a Rapture or 2012 or any sort of apocalypse of supernatural nature because IT JUST WON'T HAPPEN. The same stuff has been predicted since the beginning of story telling. It gets people to listen, puts fear in them, sometimes this can make them easier to control. Any sensible person can usually see right through this kind of stuff, but there really are idiots out there that believe every 'prophecy' they hear.

Also, like I said, it's boring. Compared to the real threats to life on Earth, the righteous ascending and months of war with demons just seems 'meh.' When we talk of giant rocks smashing into the Earth, or the immense power of the Sun, or a gamma ray burst which would microwave all life off the surface of the Earth, now those are powerful demises that should be feared.

This Book = Awesome.
Luckily those situations are most likely far off. If you would like to learn more about them or others, I would definitely check out Phil Plait's Death From The Skies! Which I also happen to be currently reading and enjoying thoroughly. So enjoy this coming weekend, bet on some horses, and sip on a Black-Eyed Susan (here's a good recipe).