Friday, May 6, 2011

May's Astronomy Day

Tomorrow is Astronomy Day. The first of two throughout the year, the other is on October 1st. Astronomy Day runs on the slogan "Bringing Astronomy to the People." I had mentioned the event in this month's Highlights.

Around the world local astronomical societies, planetariums, museums, and observatories will be sponsoring public viewing sessions, presentations, workshops, and other activities to increase public awareness about astronomy and our wonderful universe. It is a way for the general public and various astronomy enthusiasts, groups and professionals to interact. You can learn more from your local astronomy club or planetarium, or by visiting the Astronomical League's website.

I will be giving my 'Life in the Universe' presentation to a youth group from the Space Telescope Science Institute, which I am pretty excited about. And the astronomical society that I am a member of, the Harford County Astronomical Society, will be hosting it's monthly open house. Which will include a presentation from the Society's President Tom called "The Sun, the Outer Solar System and New Planet Discoveries." These kinds of events are happening all over the world, so if you have an interest in astronomy, I really suggest you check them out. Plus they are FREE.

The Eta Aquarids Meteor Shower also continues this weekend. So if you go out, you might get a chance at seeing a couple of meteors streak across the night sky! 

In addition to that, Mother's Day is also Sunday, so I hope you all treat your mothers nice. Maybe take her to dinner or get her a card or tell her you love her or something. Have a good weekend and word to your mother.

P.S. There might not be any updates this weekend since I'll probably be busy, see ya'll next week.

Thursday, May 5, 2011

Earth's Gravity Distorts Space and Time.

We are surrounded by swirling and distorted time and space, and no this not the effect of the Cinco de Mayo tequila... Well maybe some of it is...

Distorted space and time around Earth. (Credit: Stanford)

Yesterday NASA announced that Gravity Probe B (GP-B) confirmed two of Einstein's space-time theories. The first is the geodetic effect, or the warping of space and time around a gravitational body. The second is frame-dragging, which is the amount a spinning object pulls space and time with it as it rotates.

It is OK to be asking 'what are these theories and what probe' and 'when did this mission happen'. Honestly, it was tucked into a corner of my mind that I had entirely forgotten about until I got about half way through reading the NASA release.

I don't want to lose to many people on to many of the boring aspects of this mission, as it requires a good knowledge of physics. If you are interested in some of the deeper science behind the mission, I recommend checking out

The result is that we now know that there is a space-time vortex around Earth, and its shape precisely matches the predictions of Einstein's theory of gravity.

A much more detailed and science-y image. (Stanford)

Often times general relativity is thought to be one of those things where there will never be definitive proof, but this experiment changed that. One of the reviewers of the Gravity Probe B's results, Clifford Will of Washington University in St. Louis, predicts "this will be written up in textbooks as one of the classic experiments in the history of physics."

The idea behind it is that, according to Einstein's theories, time and space are woven together into a four-dimensional sheet called "space-time." The mass of objects, like the Earth, creates dimples in this fabric. Now the Earth also spins, which twists the dimple. Imagine something spinning in a jar of honey, the honey around the object gets pulled with the spin.

This is was what GP-B was created to detect. After over 40 years in development, it was launched in 2004, making this project one of the longest running in NASA's history. The idea of the experiment was simple, but a monumental task to pull off.

The basic idea is that there are 4 gyroscopes put into space. The gyroscopes have a spin axis pointed at a fixed reference point, a distant star. If free from external influence, the gyroscopes should point at the star forever. However, if space is twisted, over time they will drift off of the star. The change in direction relative to the star can be used to measure the twists of space-time.

One of the gyroscopes. (Stanford)

The epic part comes from what was done to perform this experiment. The gyroscopes are the most perfect spheres ever made by humans. At 1.5 inches across, their surfaces never vary more than 40 atomic layers.

Thirteen new technologies were invented for GP-B, including a way to measure gyroscopes without disturbing them. These new technologies have been used in various way already. This includes systems that allow airplanes to land unaided, GPS technologies, drag-free satellite concept that allows for Earth observing satellites, determining the cosmic background radiation, and magnetic field shielding.

The other cool thing is that this data proves the existence of distorted space-time. It can be duplicated when studying other celestial bodies. It has been suggested that in regions with a large and active space-time vortex, you could see a whole manner of distortions. In a system as complicated as black hole binary - one black hole orbiting another - space-time would be entirely flipped over.

Hundreds, maybe more then a thousand, people have been involved with this experiment. A lot of them are young, including high school students and undergraduates. It was a heroic feat. The probe was decommissioned in December 2010 and ceased data collection, but will have a long-term impact on physics.

Additional Reading:

Wednesday, May 4, 2011

May the Fourth

May the fourth be with you. Happy Star Wars Day!

Yeah, I totally outed myself as a Star Wars fan. But honestly, this is an astronomy blog, so it can't be that surprising. Though people have pegged me for a Star Trek fan instead. Star Trek is good an all, but I ain't no Trekkie. Give me mystical space wizards with laser swords over super-intelligent space elves with autism any day.

Both have fascinating and complex galaxies, and I guess the biggest difference is that Star Trek is us in the future, in our own galaxy and exploring. Star Trek is more based in reality I'd guess. Star Wars is totally out there with anything possible, an entirely different galaxy with a different history built from the ground up. Having an entire galaxy to work with leaves for a fantastical amount of space for the expanded universe.

And though the expanded universe is pretty deep (and I've read a good chunk of it since the 5th grade, and not the little kids books, I started with the Hand of Thrawn) I don't keep up with it much anymore. After the whole 20 years later thing with Luke having a kid, I kinda got outta it. Occasionally I'll catch the Clone Wars cartoon, but I just feel meh about it.

The real draw of Star Wars are the movies. The original trilogy. It wasn't an overly complex story, and the basic use of character archetypes was enough to suck my in as a kid. That and the sights and sounds were believable, compared to the other stuff in the day. Star Wars made special effects what it is today and was able to get all the sounds for that world perfect. I love my dad for showing me those movies as soon as possible.

The new movies aren't too bad, I like them, but they don't quite live up to the original's standard. All the CGI felt like plastic molding over everything. But, I have to admit they were still better movies then most of the other crud Hollywood has been churning out.

I have to be honest, the prospect of exploring and studying the distant reaches of the galaxy helped inspire me to pursue studying astronomy. With out Star Wars I probably would have become something silly like a business or government major, maybe Biology or English? Heck I have a minor in international relations, I could have go on to international law. But the Universe is out there waiting to be seen.

So that's it for today. No astronomy stuff, just praise for Star Wars, cuz ima geek like that.

Also, my favorite is Return of the Jedi. Don't hate, people get so stuck up on the Ewoks.
But lots of awesome things happened: Jabba's palace, Yoda reveals truths on his deathbed,
huge space battle between good and evil, It's A Trap, and the Empire is finally defeated.

Astro-Lesson: The Sun

So this weeks lesson is about the Sun. Our home star is the very thing that makes life possible here on Earth. At a mere 93 million miles away in the center of our solar system, the Sun dominates our sky. By comparison, the next closest star, Proxima Centauri, is just over four light years away. The warmth of the Sun's glow provides a climate on Earth perfect for life. It's closeness also makes it the easiest and best studied star in the Universe.

The Sun as seen from Earth's surface. (Wiki)

For as close and well studied as the Sun is, we still still don't know a whole lot. But astronomers are working hard on it every day. In fact, knowing that we don't know things about the Sun is helping us to look harder for more and more answers. But, what we to know is simply amazing. The Sun is a dynamic changing body, the intricacies are beautiful when seen, and the power is awe inspiring.

Our Sun is a middle-aged yellow dwarf star, designated as a G V star. The Sun is approximately 4.6 billion years old, with about 6.3 billion left. There are some misnomers in calling it a yellow dwarf. The first is that the Sun isn't actually yellow, it emits white light. The Sun is also huge, it makes up 99.86% of the mass of the Solar System and has a diameter of 1.4 million kilometers, that's equivalent to 109 Earths lined up side by side. Volume-wise, the Sun is 1.4 x 1027 cubic meters, big enough to fit 1.3 million Earths inside with room to spare.

Our Sun is a Yellow Dwarf.

When compared to other stars, the Sun is tiny next to the largest known stars. VY Canis Majoris has an upper limit of more then 2,100 times the size of the Sun, it's surface would extend out past the orbit of Saturn. Other estimates say VY Canis Majoris is smaller, but the surface would still extend out around the orbit of Mars. But these huge stars are really rare, in fact, small stars dominate the cosmos and it is now known that the Sun is larger than 80% of stars in the Milky Way. For a long time people have been saying the Sun is an average star, but it is anything but that, only about 10% of stars are like the Sun.

Another unique thing about the Sun is that it is a Population I star, meaning it is metal-rich. (In astronomy jargon, anything that isn't hydrogen or helium is called a metal, it makes little sense, but it makes the universe sound more awesome.) These metals were seeded by the shockwaves of nearby supernovae that triggered the formation of the Sun. The other classification is Population II stars, which are metal poor, but more on that another time, I am thinking of doing star classifications next week.

All these metals, like carbon and oxygen, make up a whooping less the 2% of the Sun's mass. Three quarters of the mass is hydrogen, and the remainder is helium. Hydrogen is the simplest and most common element in the Solar System, as well as the Universe. Inside stars like the Sun, fusion takes place that creates helium and heavier elements up to iron. Everything heavier then iron needs a supernova-type event to be created.

Needless to say, the Sun is also extremely hot. As fusion takes place it generates a lot of heat that gives the Sun life. Its surface (photosphere) temperature is roughly 5800 K based on measurements. Other layers vary in temperature, and are harder to study since we cannot see into the Sun, but modelling suggests the core of the Sun is a roaring 15,000,000 K. Not an ideal place to spend summer vacation.

Earth to Sunspot size comparison. (Source)

This heat and pressure causes the matter that makes up the Sun exist in the fourth state of matter, plasma. The plasma flows along magnetic fields that weave complexly through the Sun. The hot plasma rises to the surface and creates a boiled look on the surface of the Sun, a granulated texture, and as the plasma cools, falls back into the Sun. Often a large region becomes isolated because of the magnetic fields, and as the plasma in this region cools, it appears darker then the surrounding area. These are sunspots, and although cool regions they are still a blistering 3700 K. Many are as big as Earth!

Solar Prominence with Jupiter and Earth for comparison. (Wiki)

Sometimes these magnetic fields snap out into space an draw plasma along in arcs and lines. When looking at the chromosphere of the Sun through a safe telescope, these appear as filaments and prominences. If they break away from the Sun, they become known as solar flares, small plasma storms that fling out into space. These can potentially be hazardous to Earth, but our magnetic field protects us from most damage. The magnetic activity that causes sunspots and flaring is cyclic, running about 11 years, and we are currently heading into a peak.

Cartoon of the formation of CME, once the center point, it pushes out the CME. (NASA)

There is another type of storm that comes from the Sun, known as a coronal mass ejection, or CME for short. These are a lot larger and potentially more dangerous. These originate in one of the Sun's outer layers, the corona, and are massive blast of the solar wind, light plasma, and electromagnetic radiation. These are caused by similar magnetic activity to that which causes solar flares, but on a much more massive scale. They happen often and generally are not dangerous, but occasionally large and powerful ones can occur. These large CMEs are capable of disrupting communications and power networks on Earth.

Image of a CME launching from the Sun. (NASA)

The CMEs and flares are propagated throughout the Solar System on the solar wind. The solar wind is made up of charged particles ejected from the Sun. Their high kinetic energy allows them to escape the gravity of the Sun. The solar wind is generally what causes aurora and the plasma tails of comets. It exerts a slight push, since the wind has a mass.

I like that this image already has all the info in it already and I don't need to make a caption... oh..

The wind inflates a vast bubble around the Solar System in the interstellar medium. This bubble is known as the heliosphere, and is the out-most atmosphere of the Sun. (Yes, you reside in the Sun's atmosphere.) The edge of this is currently being studied to build a fuller model of our Sun. Currently, the Voyager probes are crossing the boundary into interstellar space, which appears to be just inside of the Oort cloud which surrounds the Solar System.

The idea of making a model of the Sun seems like an easy thing to do, but as astronomers have learned more about the Sun, the more questions arise. It is incredible complex, and we have very little understanding of the Sun's interior. One of the most ambitious projects I heard about when I studied astronomy was building a simulation from the surface of the Sun to the edge of interstellar space. It isn't a thing that has been done yet, and the computational power may not even be available. It would have to cover over 13,463,808,363 km.

What our Solar System might look like on the outside. (NASA)

I hope you now have a much better understanding of our closest star, the Sun. More is being learned about it all the time. Several observatories are working on studying solar storms and perhaps ways to predict them so we can be prepared when they hit. We also learn more about the origin and composition of our home. It is also important to understand that the Sun is changing over time, and is getting hotter. We can study to understand the future of the Sun, and its affects on the Earth (spoiler alert: all life on it will die).

Additional Reading and Sources:

Monday, May 2, 2011

Decrease the Suck, Increase the Awesome

So NASA now has an unofficial new slogan. I kinda like it. It's pretty true of what NASA does and comes from an inventive vlogger Hank Green. The most recent video can be seen below, which NASA helped to make.

It initially started with Green's video "Top 5 Awesome Things About the Webb Telescope" and has been quickly taken up by the community as a great way to describe NASA and reasoning for supporting continued scientific support in the United States. It is especially important Congress is debating the science budget that currently leaves scientists in limbo. The main thing that is clear is that both the House and the Senate are proposing cuts to science funding, with the most massive proposed cuts coming from House Republicans. (See this Nature chart for the numbers) Those cuts also include the EPA, NIST, NSF, Department of Energy, NIH and CDC.

I had also recently mentioned SETI's budget woes, and donated $5 to the cause. But over at ╬╝cosmologist they have a great infographic on SETI. Of course, if you need a good reason why you should support SETI, listen to the words of Carl Sagan.

There is also the good news that Osama bin Laden is dead, as I'm sure most of you have heard by now. I don't know that some of the celebrations over the death of a man  are warranted, it is better move for humanity though, decreasing the suck. But, I do have to mention one observation that kinda struck me, a tweet from Neil deGrasse Tyson: Two American goals that took a decade, and more than $100 billion to achieve: 1) Walk on the Moon 2) Find Bin Laden.

From xkcd, another wonderful webcomic.

I try to imagine a world, were after the decade spent going to the Moon, we spent the subsequent decades pushing further out into space, where now we could be exploring the Outer Solar System more then just by sending the occasional probe out there. It could have been an even more amazing time, and we may have avoided a reality with the disasters committed by those who seek only to inspire terror and fear.

I think a befitting line for this is the hover text quote from that comic above: "The Universe is probably littered with the one-planet graves of cultures which made the sensible economic decision that there's no good reason to go into space -- each discovered, studied, and remembered by the ones who made the irrational decision."

It's a sobering time, but I'm also optimistic about it. We are in a Golden Age of astronomy, we have learned more about our place in the Universe in the past 20-50 years then in the entirety of human history. It's a great feeling. For the first time we are able to put telescopes into space to peer into its darkest corners and listen to its darkest secrets. We cannot allow those eyes and ears to be shut, eventually we will need to seize upon the stars. The Earth won't be habitable forever, something we are becoming more and more aware of through the study of our home.

But more countries are getting into the space business. With China ramping things up and Iran looking at getting into the fray, as well as SpaceX pioneering corporate space flight, we are on the brink of a new space race that might just kick start a change in U.S. policy. The future is space, there is no doubt about that, its just a matter of making people believe in decreasing the suck and increasing the awesome.

On a more positive/humorous note, I thought this film looks kinda awesome based off of the trailer:

From the description:

Buddy Holly Is Alive And Well on Ganymede
Based on the book by Bradley Denton, John Heder plays Buddy Holly who is still very much alive and working on secret space missions across the universe. Here is the first teaser trailer for the film. Looks extraordinarily sweet.
Here's a synopsis of the novel:
When televisions worldwide begin broadcasting a nonstop, noninterruptible live performance by Buddy Holly purporting to originate somewhere in the vicinity of Jupiter, Oliver Vale—the apparent object of the broadcasts—finds himself drafted for a mission so secret that even he is not sure of its purpose. Denton fills this supremely funny novel with warring space aliens disguised as humans, a robot dog, a psychopathic assassin, an overzealous psychologist and her jealous husband, a motorcycle gang, and a messianic televangelist—all to prove that rock 'n' roll never really died.

Sunday, May 1, 2011

May 2011 Highlights

Another month is upon us, and summer is coming fast here in the Northern Hemisphere. By the end of the month, barbeques will be firing up across the U.S. for Memorial Day and thousands of students will be getting out on summer vacation. The weather will also hopefully stabilize and we will get some nice, crisp, late spring nights with great viewing. Here are some of the things you can hope to catch during the month of May:

May 2: Endeavour Launch: The next attempt to launch this shuttle on its final flight will be at 2:33 p.m. EDT. The launch has been further delayed, a week or more. The next launch will be no sooner then May 8. As the shuttle would have to clear the way for an Air Force launch on the 6th. The reason for delay is indications that issues with the APU-1 heating that caused the initial shutdown are symptoms of a deeper problem that will take engineers longer to access and fix.You can find the latest news on NASA's Shuttle site.

May 3: New Moon: The Moon will be directly between the Earth and the Sun and will not be visible from Earth.

May 5 & 6: Eta Aquarids Meteor Shower: (active through May 12) A light meteor shower generated from Earth passing through dust released by Halley's Comet. You can see between 10 to 30 meteors per hour during the peak on May 5 & 6. You'll want to look towards the constellation Aquarius to the east after midnight, far from city lights.

May 7: Astronomy Day (Part 1): An event that happens twice a year that aims to bring astronomy to the people, it is a way for the general public and various astronomy enthusiasts, groups and professionals to interact. All around the world stargazing and astronomy clubs and other organizations plan to hold events. You can learn more from your local astronomy club or planetarium, or by visiting the Astronomical League's website. The next astronomy day is October 1.

May 10: First Quarter Moon: The Moon is halfway through the waxing phase, a great time for observing as the shadows provide wonderful contrast.

May 11: Mercury, Venus, and Jupiter: These three planets will be in conjunction, forming a 2-degree vertical line in the early morning sky to the east. Mars will also be visible nearby. 

May 17: Full Moon: The Moon will be directly opposite the Earth from the Sun and will be fully illuminated as seen from Earth. This moon, in the Native American tradition of naming the full moons throughout the year, is known as the Full Flower Moon, because this is the time of year when spring flowers appear in abundance.

May 24: Last Quarter Moon: Halfway through the Moon's waning phase, The next New Moon will be June 1st.

Saturn will dominate the evening night sky for the entire month of May, so if you happen to be out and look up, it will probably be the brightest object in the night sky besides the Moon.

That's about all the exciting observable stuff happening in the month of May. If anything else comes up, I'll be sure to mention it.