If you’re looking to while away a Friday afternoon in Vancouver, check out this lecture going on at the Rio Theatre on September 17th, 2010 at 12:00pm. There’s going to be an all-star group of lecturers, including Jeremy Heyl, Gaelen Marsden from the BLAST mission, and Dr. Jaymie Matthews, principle investigator with Canada’s MOST Space Telescope.
There are tickets for sale, but the organizer has agreed to let 50 Universe Today readers in for FREE. If you live in the Vancouver, BC area, just email the organizer at i[email protected] and let them know you’d like a free ticket.
Look! Up in the sky! Is it a bird? Is it a plane? No… It’s super Jupiter! “Jupiter is always bright, but if you think it looks a little brighter than usual this month, you’re right,” says Robert Naeye, editor in chief of Sky & Telescope magazine. “Jupiter is making its closest pass by Earth for the year. And this year’s pass is a little closer than any other between 1963 and 2022.”
Where do you find Jupiter? Try about 368 million miles away and (for most observers) low to the southeast after the skies get dark. The giant planet will reach its nearest point to us on the evening of September 20, 2010 – but will remain one of the brightest objects in the night through the end of the month.
Why does Jupiter appear to be more luminous now than at any other time? Although the varying distances over the years may seem marginal – about 10 to 11 million miles over a period of around 60 years – it translates into significance when it comes to magnitude factors. At its brightest, Jupiter can reach –2.94, and dimmest at -1.6. Just a 1% distance change can mean either 4% brighter or dimmer!
The mighty Jove has also undergone some cosmetic changes in the past year as well, making it an additional 4% brighter than usual.
For nearly a year the giant planet’s South Equatorial Belt has slowly been covered by a highly reflective ammonia cloud. Normally the SEB appears to be brown, a result of Jupiter’s chemical compounds reacting to the Sun’s ultraviolet light. Known as “chromophores”, these chemicals are known to mix with lower cloud decks and just a few stormy days could mean rising convection cells are forming crystallized ammonia – masking the light absorbing dark zone and adding to reflectivity.
Of course, a close pass doesn’t mean Jupiter is going to appear to be the size of the Moon – nor be as bright – but it’s certainly going to make a grand appearance on the nights of September 22 and September 23 when it joins Selene on the celestial scene!
But that’s not all that’s happening here. According the Sky & Telescope Magazine: Jupiter and Uranus find themselves close to the point on the sky known as the vernal equinox, where the Sun crosses the celestial equator on the first day of spring. (“Spring” here means spring in the Northern Hemisphere.) And, all of this takes place around the date when fall begins in the
Northern Hemisphere: on September 22nd. (Fall begins at 11:09 p.m. Eastern Daylight Time on that date.)
What do all these coincidences mean? “Nothing at all,” says Alan MacRobert, a senior editor at Sky & Telescope. “People forget that lots of things are going on in the sky all the time. Any particular arrangement might not happen again for centuries, but like the saying goes, there’s always something. Enjoy the show.”
A daytime shot of the Star Field for the 2010 Iowa Star Party held at Whiterock Observatory. 36 participants showed up to take in the incredibly dark skies. Image Credit: Andrew Sorenson
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If you’ve been wanting to get out to view the skies at night from your back yard – or maybe a darker location – but don’t know your way around the skies or have access to a telescope or binoculars, attending a star party may be just what you need to do. I recently attended the 8th annual Iowa Star Party under the dark skies of Coon Rapids, Iowa.
It was an extraordinary experience to meet other amateur astronomers, look at (and through) their telescopes, and in general to be surrounded by a bunch of other people keenly interested in astronomy. Here’s a brief synopsis of what my experience at the star party was like, followed by reasons to seek out a dark-sky gathering near you and a few links to large star parties around the world.
The star party ran from Thursday, September 2nd through Sunday the 5th. In attendance over the weekend were 36 participants and their families, most from Iowa but a few from Minnesota, Nebraska and Illinois. It’s no Astrofest, but it was a good showing for Iowa!
The Iowa Star Party is located at the Whiterock Conservancy, an non-profit land-trust that is gracious enough to host the party every year, and has named the field in which the ‘scopes are located the Star Field. The site was chosen by former Ames Area Amateur Astronomers member Dave Oesper because it is the least populated place with the lowest amount of light pollution in central Iowa. The Ames club, of which I am a member, did much of the organizing for the event. All three nights were perfectly clear with good seeing, and though it was really windy during the daytime, it tended to calm down towards the evening.
I was not personally able to attend the first evening, but it was reportedly cold and clear, and the few that did show up for the kickoff were treated to dark, clear skies and little wind. Friday was the public night, where anyone from anywhere was invited to come look through a scope and attend a talk about the history of astronomy and some general information about viewing by local amateur astronomer Drew Sorenson.
The talk ended in a “debate” about refractors vs. reflectors that turned out to be a surprise, unplanned marshmallow fight. Yeah, we threw marshmallows at each other – with gusto I might add. A 60mm homemade refractor was then raffled off as a door prize.
175 members of the public showed up for a short presentation and a long night of good viewing on Friday at the Iowa Star Party. Facing the camera at the table are Emily Babbin of Whitrock Conservancy, center, and Al Johnson, Vice President of the AAAA, right. Image Credit: Andrew Sorenson
In all, 175 people showed up for what turned out to be a spectacular night under some of the darkest skies I’ve seen. Members of the public were treated to a spectacular view of the Milky Way, as well as views of Jupiter, M13, Mizar, Albirio, and countless other objects through the eyepieces of about 20 telescopes.
Saturday night, the last evening of the star party, there was a banquet followed by a talk by Dr. Charles Nelson, Drake University Assistant Professor of Astronomy. Dr. Nelson gave a talk about quasars, which included a brief history of their discovery and the techniques we use to study and analyze them today, with a heavy emphasis on spectroscopy. After the talk, everyone headed out to the Star Field to spend the rest of the dark night observing.
Objects that my club viewed included the Veil Nebula (which was stunningly large and wispy through my club’s 24″ telescope), Herschel’s Garnet, the Whirlpool Galaxy, the Andromeda Galaxy, M31, M22 and Jupiter and Uranus. Other participants viewed the quasar Markarian 205, in keeping with the quasar-themed lecture.
We concluded Sunday with a breakfast, during which I made countless pancakes faster than I’ve ever made pancakes before. Staying up all night staring at the stars makes one hungry!
This is just a small taste of my own individual experience, but all of this fun and more could be had by you! Here are a few reasons to seek out your own star party:
– You might will learn something – No matter how much time you spend at a ‘scope, meeting with other amateur astronomers will give you ideas and techniques and knowledge that you couldn’t even dream of discovering on your own. Plus, it’s fun to share an interest in any subject with other human beings, face to face.
– You’ll see more than you would at home – Larger star parties are inherently located in areas with very dark skies, meaning that there will be so much more to see than you could at home. Even smaller star parties near towns tend to avoid locations that are polluted by city lights. Plus, there will likely be people there with huge telescopes that are more than willing to show you all that a large light bucket has to offer. – You can share your knowledge of the skies – A star party is a great chance to show off your knowledge of the skies to other amateurs, as well as members of the public if there is a public viewing night.
– You will meet other astronomers – Sure, amateur astronomy can be a lonely hobby, spending hours outside in the dark when everyone else is asleep. But at a star party, you’ll get the chance to share your passion for the skies with other astronomers, look through their telescopes and show them your own. You’re not alone!
-You’ll have fun – Even if you have a passing interest in astronomy and/or don’t own a telescope or binoculars, looking through a telescope is just plain cool, and getting to know your way around the skies is always a treat. And if it clouds over, chances are that someone will bring old episodes of Star Trek to watch!
If you’re interested in finding your nearest star party, here are a few resources to take a look at.
In the United States, The Astronomical League compiles a list of upcoming star parties and astronomy-related events on their website and in their print newsletter, The Reflector.
Of course, this only covers our readership located in the predominantly English-speaking regions of the Earth, so if you have a favorite event near you, feel free to link to it in the comments. Also share your favorite memory of a star party in the comments section, if you feel moved to do so.
As amateur astronomers are wont to say, “Clear Skies!”
Engineers install the six wheels on the Curiosity rover. Credit: NASA/JPL-Caltech
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NASA’s next Mars rover, the Mars Science Laboratory, or Curiosity, is scheduled to launch from Cape Canaveral in Florida in late 2011, and arrive at a yet undecided region of Mars in August 2012. The goal of Curiosity is to assess whether Mars ever had an environment capable of supporting microbial life and conditions favorable for preserving clues about life, if it existed. JPL put together a list of five intriguing things about Curiosity:
An artist's concept of NASA's Mars Science Laboratory (left) serves to compare it with Spirit, one of NASA's twin Mars Exploration Rovers. Credit: NASA/JPL-Caltech
1. How Big Is It?: The Mini Cooper-sized rover is much bigger than its rover predecessors, Spirit, Opportunity and Pathfinder. Curiosity is twice as long (about 2.8 meters, or 9 feet) and four times as heavy as Spirit and Opportunity, which landed in 2004. Pathfinder, about the size of a microwave oven, landed in 1997.
2. Landing–Where and How: In November 2008, possible landing sites were narrowed to four finalists, all linked to ancient wet conditions. NASA will select a site believed to be among the most likely places to hold a geological record of a favorable environment for life. The site must also meet safe-landing criteria. The landing system is similar to a sky crane heavy-lift helicopter. After a parachute slows the rover’s descent toward Mars, a rocket-powered backpack will lower the rover on a tether during the final moments before landing. This method allows landing a very large, heavy rover on Mars (instead of the airbag landing systems of previous Mars rovers). Other innovations enable a landing within a smaller target area than previous Mars missions.
3. On-board Toolkit: Curiosity will use 10 science instruments to examine rocks, soil and the atmosphere. A laser will vaporize patches of rock from a distance, and another instrument will search for organic compounds. Other instruments include mast-mounted cameras to study targets from a distance, arm-mounted instruments to study targets they touch, and deck-mounted analytical instruments to determine the composition of rock and soil samples acquired with a powdering drill and a scoop.
4. Big Wheels: Each of Curiosity’s six wheels has an independent drive motor. The two front and two rear wheels also have individual steering motors. This steering allows the rover to make 360-degree turns in-place on the Mars surface. The wheels’ diameter is double the wheel diameter on Spirit and Opportunity, which will help Curiosity roll over obstacles up to 75 centimeters (30 inches) high.
5. Rover Power: A nuclear battery will enable Curiosity to operate year-round and farther from the equator than would be possible with only solar power.
Dust Pillars in the Carina Nebula. Astronomers are peering inside Carina's pillars to get new details about starbirth activities. Credit: NASA, ESA, and the Hubble Heritage Project (STScI/AURA) Acknowledgment: M. Livio (STScI) and N. Smith (University of California, Berkeley)
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What can we say? Another Hubble stunner, and just wait until you see flythough video below. This is an absolutely gorgeous look inside the Carina Nebula. The radiation from massive stars inside the nebula eats away at cold molecular clouds, creating bizarre, fantasy-like structures. These are one-light-year-tall pillars of cold hydrogen and dust, imaged by the Hubble Space Telescope’s Advanced Camera for Surveys, in a composite image from observations taken in 2005 in hydrogen light (light emitted by hydrogen atoms) along with observations taken in oxygen light (light emitted by oxygen atoms) in 2010. What Hubble can see from about 7,500 light-years away is nothing short of breathtaking.
Here’s the regular video – in which there are 3-D-type flythough effects:
In terms of physics, absorption is defined as the way that energy from photons is taken up by matter, and transformed into other forms of energy, like heat. All of the light in the electromagnetic spectrum is made up of photons at different energy levels. Radio waves are photons with lower amounts of energy, and gamma rays are photons with very high levels of energy. When a photon strikes matter, it can either be reflected or absorbed by the material. And if it is absorbed, the energy of the photon is transformed into heat.
The absorbance of an object is a measure of what percentage of the electromagnetic radiation it’s likely to absorb. Transparent or reflective objects absorb much less than opaque, black objects.
This concept is very important to astronomers, who are able to measure which wavelengths of light are being absorbed by an object or cloud of gas, to get an idea of what it’s made of. When you put the light from a star through a prism, you get a spectrum of the light coming from that star. But in some spectra, there are blank lines, gaps where no photons of a specific wavelength are being emitted. This means that some intervening object is absorbing all of the photons of this wavelength.
For example, imagine looking at how the light from a star passes through a planet’s atmosphere which is rich in sodium. This sodium will absorb photons at a specific wavelength, creating gaps in the spectrum from the light of the star. By comparing these gaps to the absorption line pattern of known gasses, astronomers can work out what’s in the planet’s atmosphere. This general method is used in many ways by astronomers to learn what distant objects are made out of.
The opposite of absorption is emission. This is where different elements will release photons when they’re heated. Different elements will release photons at different levels of energy, and their colors on the electromagnetic spectrum help astronomers discover what elements the object is made out of. When iron is heated, it releases photons in a very specific pattern, different from the pattern released by oxygen.
Both the absorption and emission serve as a fingerprint to help astronomers understand what the Universe is made out of.
We have written many articles about Absorption Spectroscopy for Universe Today. Here’s an article about amateur spectroscopy, and here’s an article about the light spectrum.
If you’d like more info on Absorption Spectroscopy, check out the Principles of Spectroscopy, and the Infrared Spectroscopy Page.
Magnets are the unsung heroes of the Modern Age. However most people don’t really understand what are magnets made of and how they even work. The issue is that we just know that magnets attract iron and nickel. However, magnets have a very interesting origin and can be seen as a physical manifestation of the electromagnetic force.
All magnets are made of a group of metals called the ferromagnetic metals. These are metals such as nickel and iron. Each of these metals have the special property of being able to be magnetized uniformly. When we ask how a magnet works we are simply asking how the object we call a magnet exerts it’s magnetic field. The answer is actually quite interesting.
In every material there are several small magnetic fields called domains. Most of the times these domains are independent of each other and face different directions. However, a strong magnetic field can arrange the domains of any ferromagnetic metal so that they align to make a larger and stronger magnetic field. This is how most magnets are made.
The major difference among magnets is whether they are permanent or temporary. Temporary magnets lose their larger magnetic field over time as the domains return to their original positions. The most common way that magnets are produced is by heating them to their Curie temperature or beyond. The Curie temperature is the temperature at which a ferromagnetic metals gains magnetic properties. Heating a ferromagnetic material to its given temperature will make it magnetic for a while. While heating it beyond this point can make the magnetism permanent. Ferromagnetic materials can also be categorized into soft and hard metals. Soft metals loses their magnetic field over time after being magnetized while hard metals are likely candidates for becoming permanent magnets.
Not all magnets are manmade. Some magnets occur naturally in nature such as lodestone. This mineral was used in ancient times to make the first compasses. However, magnets have other uses. With the discovery of the relation between magnetism and electricity, magnets are now a major part of every electric motor and turbine in existence. Magnets have also been used in storing computer data. There is now a type of drive called a solid state drive that allows data to still be saved more efficiently on computers.
We have written many articles about magnets for Universe Today. Here’s an article about the Earth’s magnetic field, and here’s an article about the bar magnet.
Fermi mapped GeV-gamma-ray emission regions (magenta) in the W44 supernova remnant. The features clearly align with filaments detectable in other wavelengths. This composite merges X-ray data (blue) from the Germany/U.S./UK ROSAT mission, infrared (red) from NASA’s Spitzer Space Telescope, and radio (orange) from the Very Large Array near Socorro, N.M. Credit: NASA/DOE/Fermi LAT Collaboration, NASA/ROSAT, NASA/JPL-Caltech, and NRAO/AUI
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In the universe there are kinds of energy and different ways it manifests itself. One common form is radiation. Radiation is the wave energy produced by electromagnetic forces. There are different kinds and their strength can be divided into three categories. There are alpha rays, beta rays, and finally gamma rays. Essentially each example is high energy particles traveling in a straight line. However, there are limits for level. Alpha rays are the weakest and can be blocked by human skin and gamma rays are the strongest and only dense elements like lead can block them.
So what are gamma rays? Gamma rays are the strongest from of radiation. This is what makes nuclear radiation so dangerous. This high energy form of radiation can damage human tissue and cause mutations. In circumstances where gamma radiation is plentiful most life forms would be killed within a short amount of time.
Gamma rays differ from alpha and beta waves in their composition. Alpha and beta rays are composed of discrete subatomic particles. This is part of the reason why these rays are more easily deflected by less dense matter. Gamma rays are on a whole different level. They are pure energy and radiation so only the most dense kind of matter can deflect it.
Gamma rays can be found practically anywhere in the universe. The best example is celestial bodies like the sun, pulsars, and white dwarfs. Each of these are massive sources energy burning off hydrogen in massive nuclear reactions. This produces massive amounts of radiation in the form of rays. Outside of the Earth’s protective atmosphere the radiation manifests itself in cosmic rays. Cosmic rays carry tremendous amounts of energy but what makes them pack such a punch are the gamma rays that they are made up of.
The most interesting characteristic of gamma rays is that they don’t have a uniform energy level. In some cases the energy levels vary so much you can have gamma rays that meet every criterion for the term but in the end have less energy than an x ray from a X ray machine at the hospital. The energy of the gamma ray largely depends on the source and production of the radiation.
In the end Gamma rays are one the many interesting energy phenomena in our universe and scientist are constantly looking to learn more about them and gain a better understanding of their properties.
What is solar energy? Solar energy is the radiant energy produced by the Sun. It is both light and heat. It, along with secondary solar-powered resources such as wind and wave power, account for the majority of the renewable energy on Earth.
The Earth receives 174 petawatts(PW) of solar radiation at the upper atmosphere. 30% of that is reflected back to space and the rest is absorbed by clouds, oceans and land masses. Land surfaces, oceans, and atmosphere absorb solar radiation, which increases their temperature. Warm air containing evaporated water from the oceans rises, causing convection. When the air reaches a high altitude, where the temperature is low, water vapor condenses into clouds and causes rain. The latent heat of water condensation increases convection, producing wind. Energy absorbed by the oceans and land masses keeps the surface at an average temperature of 14°C. Green plants convert solar energy into chemical energy through photosynthesis. Our food supply is completely dependent on solar energy. After plants die, they decay in the Earth, so solar energy can be said to provide the biomass that has created the fossil fuels that we are dependent on.
Humans harness solar energy in many different ways: space heating and cooling, the production of potable water by distillation, disinfection, lighting, hot water, and cooking. The applications for solar energy are only limited by human ingenuity. Solar technologies are characterized as either passive or active depending on the way the energy is captured, converted, and distributed. Active solar techniques use photovoltaic panels and solar thermal collectors to harness the energy. Passive techniques include orienting a building to the Sun, selecting materials with thermal mass properties, and using materials with light dispersing properties.
Our current dependence on fossil fuels is slowly being replaced by alternative energies. Some are fuels that may eventually become useless, but solar energy will never be obsolete, controlled by foreign powers, or run out. Even when the Sun uses up its hydrogen, it will produce useable energy until it explodes. The challenge facing humans is to capture that energy instead of taking the easiest way out by using fossil fuels.
We have written many articles about Solar Energy for Universe Today. Here’s an article about harvesting solar power from space, and here’s an article about the energy from the sun.
Continents might be necessary for life, especially complex life. This image shows super-continent Pangaea during the Permian period (300 - 250 million years ago). Credit: NAU Geology/Ron Blakey
So, you are curious about what is Pangaea? It was the supercontinent that existed 250 million years ago during the Paleozoic and Mesozoic eras. During the ensuing millenia, plate tectonics slowly moved each continent to its current position on the planet. Each continent is still slowly moving across the face of our world.
The breaking up and formation of supercontinents appears to have happened several times over Earth’s history with Pangaea being one among many. The next-to-last one, Pannotia, formed about 600 million years ago during the Proterozoic eon. Pannotia included large amounts of land near the poles and only a relatively small strip near the equator connecting the polar masses.
60 million years after its formation Pannotia broke up, giving rise to the continents of Laurentia, Baltica, and Gondwana. Laurentia would eventually become a large portion of North America, the microcontinent of Avalonia(a small portion of Gondwana) would become the northeastern United States, Nova Scotia, and England. All of these came together at the end of the Ordovician.
While this was happening, Gondwana drifted slowly towards the South Pole. These were the early steps in the formation of Pangaea. The next step was the collision of Gondwana with the other land mass. Southern Europe broke free of Gondwana. By late Silurian time, North and South China rifted away from Gondwana and started to head northward across the shrinking Proto-Tethys Ocean.
Movement continued slowly until the land masses drifted until their current positions. The list of oceans and microcontinents is too long to include in this article. We have many articles about this full process here on Universe Today. The evidence for Pangaea lies in the fossil records from the period. It includes the presence of similar and identical species on continents that are now great distances apart.
Additional evidence for Pangaea is found in the geology of adjacent continents, including matching geological trends between the eastern coast of South America and western Africa. The polar ice cap of the Carboniferous Period covered the southern end of Pangaea. Glacial deposits of the same age and structure are found on many separate continents which would have been together in the continent of Pangaea.
We know that the existence of supercontinents has been proven. We know that they have existed at different times in the Earth’s history. Also, we know that the tectonic plates are still moving. Is it possible that there will be another supercontinent someday in the distant future.
We have written many articles about Pangaea for Universe Today. Here’s an article about the Continental Drift Theory, and here’s an article about the continental plates.
