Universe Today

March 19, 2008December 26, 2015 by Fraser Cain

Geologist Finds a Meteorite Crater in Google Earth

Want to discover an impact crater, and even get it named after you? All you’ve got to do is spend a few (hundred) hours poring over images in Google Earth or Google Maps. That’s exactly what Geologist Arthur Hickman did, turning up a previously unknown impact crater when he was searching for iron ore in the mountains of West Australia.

While he was browsing through images on Google Earth, Hickman’s geology training helped him recognize the circular shape and raised rim of an impact crater. He sent a screenshot and coordinates to colleagues at Australian National University, and they confirmed that it’s a well-preserved meteor crater between 10,000 and 100,000 years old. And until now, totally unknown.

You can take a look at the crater for yourself on Google Maps.

This isn’t the first time a crater has been discovered using Google Earth. One was found in the Saharan Desert two years ago. That crater is 31 km (19 miles) across – much bigger than Meteor Crater in Arizona.

The newly named “Hickman Crater” measures 270 metres (885 feet) across, and is about 35 km north of Newman, Australia. The region was mapped by the Geological Survey of Western Australia about 20 years ago, but the crater went unnoticed until now.

Since large meteorites hit the Earth every few thousand years, and when you consider that the landscape is millions of years old, there are many regions hiding meteorite impacts.

They’re just waiting for you to find them.

Original Source: ScienceAlert

March 19, 2008December 26, 2015 by Nancy Atkinson

Great Images From the STS-123 Mission

There have been some outstanding images coming in from the current space shuttle mission at the International Space Station. The crews of Endeavour and the ISS continue their near-frantic pace of spacewalks and outfitting of the station during the STS-123 mission. During the 3rd spacewalk, astronauts Rick Linnehan (right) and Bob Behnken work on the new Dextre, also known as the Special Purpose Dextrous Manipulator (SPDM). This image highlights how big the station is getting, as the astronauts are almost dwarfed by this one area of the truss section.

Bob Behnken continues his work on Dextre during his EVA. During the 6-hour, 53-minute spacewalk, Linnehan and Behnken installed a spare-parts platform and tool-handling assembly for Dextre. They also checked out and calibrated Dextre’s end effector and attached critical spare parts to an external stowage platform. The new robotic system is scheduled to be activated on a power and data grapple fixture located on the Destiny laboratory today.

All the astronauts have had to juggle lots of different activities during the current mission. Here, Dominic Gorie, STS-123 commander, reaches for a procedures checklist floating freely on the aft flight deck of Space Shuttle Endeavour.

Can you imagine looking out a window and seeing one of your best friends floating by? Visible through a window on Endeavour’s aft flight deck is astronaut Rick Linnehan during spacewalk #3 for the mission.

For Wednesday, the astronauts are scheduled to take a half-day off to rest up for two more spacewalks. They also are continuing their work to outfit the Japanese module that was attched to the Harmony node earlier in the mission. They’ll do a round of media interviews this evening, and get ready for another spacewalk on Thursday.

Link here for more STS-123 images.

March 19, 2008December 26, 2015 by Fraser Cain

Organic Molecules Seen in an Extrasolar Planet

The Hubble Space Telescope has turned up evidence for organic molecules on a planet orbiting another star. Organic molecules? Like the stuff we’re made of? Yes, but wait, this isn’t the discovery of life. In fact, it’s just the tell-tale signature of methane in the atmosphere of a distant, superheated planet.

The Jupiter-sized extrasolar planet is called HD 189733b, and it orbits a star about 63 light-years away in the constellation Vulpecula. Astronomers discovered that the planet is a member of the “hot Jupiter” class of planets, orbiting so close to its parent star that it only takes 2 days to complete an orbit.

This close orbit, much closer than the orbit of Mercury, raises the planet’s temperature to a sweltering 900 degrees Celsius – about the same temperature as the melting point of silver.

Here’s a computer animated video of the planet.

The observations were made using the transit method. This is where the planet passes directly in front of the parent star from our perspective. As it passes in front, it dims the light from the star slightly. And there’s a special bonus. As the planet is making this transit, astronomers can measure its atmosphere.

Using a technique called spectroscopy, the astronomers were able to split the light coming from the planet to reveal the fingerprints of various chemicals in its atmosphere. They confirmed the existence of water, turned up by NASA’s Spitzer Space Telescope back in 2007. But now they also found methane.

Under the right circumstances, methane can play a key role in prebiotic chemistry – the chemical reactions considered necessary to form life as we know it. Methane has been discovered in other planets in our own Solar System, so it doesn’t mean there’s life on HD 189733b (especially with its extremely hot temperatures). But finding methane around another planet, orbiting another star is an exciting advancement.

So even though life is out of the question on HD 189733b, the technique is the major news here. Astronomers will eventually be peering at smaller, more Earth-sized planets, and will be using this method to find other chemicals of life within stellar habitable zones.

If the life’s out there, astronomers are getting closer and closer to finding it.

The discovery was published in the March 20th issue of the journal Nature.

Original Source: Hubble News Release

Posted on March 19, 2008January 24, 2021 by Tammy Plotner
Vernal Equinox Is Coming… Balance Eggs Or Believe In Science?

Spring officially arrives for everyone, including astronomers on March 20. The word “Equinox” literally means “equal night”. It’s all about the balance of light – not the myth of balancing eggs. On Thursday, both the day and night are the same length. But what’s so special about it? It’s a date that most of us recognize as symbolic of changing seasons. North of Earth’s equator we welcome Spring, while people south of the equator are gearing up for the cooler temperatures of Autumn.

These all too brief, but monumental moments in Earth-time, owe their significance to the slightly more than 23 degree tilt of the Earth’s axis. Because of our planetary angle, we receive the Sun’s rays most directly during the Summer. In the Winter, when we are tilted away from the Sun, the rays pass through the atmosphere at a greater slant, bringing lower temperatures. If the Earth rotated on an axis perpendicular to the plane of the Earth’s orbit around the Sun, there would be no variation in day lengths or temperatures throughout the year, and we would not have seasons. At Equinox, the midway between these two times in Spring and Autumn, the spin axis of the Earth points 90 degrees away from the Sun.

If your head is spinning from all of this, sit and ponder for a moment. Now is a great time to choose a marker and observe what’s happening for yourself. Trying a real science experiment for equinox is much better than the myth of balancing eggs. Just place a stake of some type into the ground (or use a fencepost or signpost) and periodically over the next few weeks measure the length of the shadow when the Sun is at its highest and write down your measurements. It won’t take long before your marker’s shadow length changes and you notice how the Sun’s position changes in the sky, and with it the ecliptic plane.

In the language of astronomy, an equinox is either of two points on the celestial sphere where the ecliptic and the celestial equator intersect. The Vernal Equinox is also known as “the first point of Aries” – a the point at which the Sun appears to cross the celestial equator from south to north. The equinoxes are not fixed points on the celestial sphere but move westward along the ecliptic, passing through all the constellations of the zodiac in 26,000 years. This is what’s known as the precession of the equinoxes – a motion first noted by Hipparchus roughly in 120 B.C. But what causes it?

The precession is caused the gravitational attraction of both the Moon and Sun on the equatorial bulge of the Earth. Imagine the Earth’s axis patterning itself in a cone as it moves, like a spinning top. As a result, the celestial equator, which lies in the plane of the Earth’s equator, moves on the celestial sphere, while the ecliptic, which lies in the plane of the Earth’s orbit around the Sun, is not affected by this motion. The equinoxes, which lie at the intersections of the celestial equator and the ecliptic, now move on the celestial sphere. Much the same, the celestial poles move in circles on the celestial sphere, so that there is a continual change in the star at or near one of these poles.

After a period of about 26,000 years the equinoxes and poles lie once again at nearly the same points on the celestial sphere. Because the gravitational effects of the Sun and Moon aren’t always the same, there is some wobble in the motion of the Earth’s axis called nutation. This wobble causes the celestial poles to move, not in perfect circles, but in a series of S-shaped curves with a period of 18.6 years that was first explained by Isaac Newton in 1687.

Go ahead and balance eggs for fun… But believe in science!

P.S. The Bad Astronomer Phil Plait has a tutorial video on his website, teaching you how to stand an egg on end, any time of the year. Click here to watch it.

Posted on March 19, 2008December 26, 2015 by Fraser Cain
Arctic’s Oldest and Thickest Ice is Melting Away

It’s been a strange year for the Arctic. During the summer, high temperatures melted away vast regions of the Arctic sea ice, opening up the Northwest Passage for the first time. But then this winter has been unusually cold, bringing back large large areas of sea ice. So what’s going on? Is the Arctic recovering, or is Global Warming marching on?

The big problem studying global warming is that the temperatures and local climate can fluctuate. Over the short term, in some regions, you can have unseasonably warm or cold temperatures. Here in Vancouver, we had one of the coldest, snowiest winters I’ve ever seen.

NASA scientists are measuring the long term trends for the ancient perennial sea ice that lasts across several seasons. And this ice seems to be melting away over the years. In the past, this perennial sea ice – anything that lasted more than a single year – covered 50-60% of the Arctic. This analysis was made by NASA’s ICESat satellite, which measures sea ice thickness with microwaves.

This year, the perennial sea ice covered only 30% of the Arctic. And the most ancient ice, that which has survived more than 6 years, used to comprise 20% of the Arctic. Now it’s down to just 6%.

As this year shows, Arctic sea ice doesn’t stand still. Its coverage grows and declines seasonally, reaching the maximum in March, and the minimum in September. And this year, the maximum is up 3.9% over the previous 3 years. At the same time, the perennial sea ice coverage is down to an all-time minimum.

As the perennial sea ice thins, it’s more vulnerable during the summer melt period to wind and waves. Large chunks of ice can be carried out of the Arctic to melt in warmer waters.

Don’t worry about water levels rising as the sea ice coverage disappears. This ice is already in the water, displacing the same amount. So as it melts, sea levels should stay right where they are. That’s different from the ice locked up in the world’s glaciers, Greenland, and the Antarctic ice cap. As those melt, sea levels will rise.

To better understand the Arctic ice coverage, NASA is planning to launch a follow-on mission called ICESat II, due for launch in 2015.

Original Source: NASA News Release

Posted on March 19, 2008December 26, 2015 by Nancy Atkinson
Arthur C. Clarke Dies

Sir Arthur C. Clarke, writer, inventor and visionary, has died from heart failure at age 90. A master of science fiction, Clarke was known most for his futuristic book â€œ2001â€ published in 1968, which was made into the landmark movie. Clarke wrote scores of fiction and non-fiction books, more than 100 short stories, and numerous articles and essays.

Some of his early books included Interplanetary Flight (1950), Prelude to Space (1951), and The Making of a Moon (1957). He wrote a series of â€œOdysseyâ€ books: 2010: Odyssey Two (1985) â€“also made into a movieâ€”and 2061: Odyssey Three (1988) and 3001: The Final Odyssey (1996). His last book was published in 2005, The Last Theorem.

Clarke foresaw many technological advances in his writing, describing, among other things, cell phones, the internet, and moon landings using a mother ship and a landing pod. He was also known as the â€œgodfather of the telecommunications satellite.â€ In a 1945 article in Wireless World magazine, he outlined a worldwide communications network based on fixed satellites orbiting at 22,240 miles (42,000 km) â€“ a geosynchronous orbit â€“ often referred to as the Clarke Orbit.

Clarke was born December 16, 1917 in Somerset, England. From an early age he was interested in astronomy and science. During World War II he was a pioneer in using radar with the Royal Air Force. Later, he completed a college degree, with honors, in physics and mathematics at King’s College in London. He was an editor for the journal Physics Abstracts when his first science fiction books were published.

Clarke spent most of his life promoting science and space exploration. He was an American Astronautical Society Fellow, the British Science Fiction Association President, an International Academy of Humanism Laureate, was on the National Space Society Board of Governors and Planetary Society Advisory Council, was a member of the Royal Astronomical Society and was Knighted by the British Empire in 2000. He has a nebula and an asteroid named after him.

Clarke suffered from post-polio syndrome since 1988 and sometimes had to use a wheelchair, but until recently, he still continued to scuba dive, one of his lifelong passions. His love of scuba diving brought him to Sri Lanka, where he lived since the 1950â€™s. Clarke once said he was â€œperfectly operational underwater.â€

On his 90th birthday, Clarke released a video, in which he talked about his life and accomplishments. â€œSometimes I am asked how I would like to be remembered,â€ Clarke said. I have had a diverse career as a writer, underwater explorer and space promoter. Of all these I would like to be remembered as a writer.â€

Posted on March 18, 2008April 26, 2016 by Ian O'Neill
Astrium Unveils New Spaceship Plans (Video Simulation & Pictures)

Europe’s leading spacecraft manufacturer EADS Astrium, the builders of the Ariane rocketÂ (that launches many of Europe’s space missions), has announced plans to mass produce the next generation of space planes. DevelopingÂ the design of a single-stage “rocket plane”, the company believes there will be a demand for 10 spacecraft per year when the space tourism idea “takes off”. Astrium won’t be running tourist trips themselves; they will simply supply the hardware to space tourism companies predicting the industry will progress along the same lines of a classical aeronautical business model. Astrium has even released an excellent and inspiring (and realistic!) promotional video simulation of the spacecraft launch and view of space…

Astrium has big plans. As space tourism companies begin to emerge, like Richard Branson’s Virgin Galactic, the technology capable of taking tourists above 100 km into the threshold of space is developing at an accelerated rate.

At first glance, the new Astrium concept looks just like a conventional jet, but this aircraft is different. For the first part of the journey high into Earth’s atmosphere, the spacecraft uses conventional jets (that require oxygen to function). At about 12 km, the jets will be rendered useless as atmospheric oxygen begins to thin out. At this point rocket engines, supplied by onboard tanks of oxygen and methane, will rumble into operation blasting the craft vertically into space at high velocity. The spacecraft will have covered 60 km in 80 seconds and will have enough momentum to continue into space, breaching the 100 km “lower limit” of space.

Watch the Astrium simulation of a trip on board the spacecraft.

Astrium forecasts a healthy market for their space planes, and although it won’t be in the same league as Boeing or Airbus, it will be a big step for space tourism.

One of the big players in the space tourism market will be Virgin Galactic. Virgin’s business plan is to sell tourist flights as well as develop and maintain their own spacecraft (by partnering with Burt Rutan’s Scaled Composites). Astrium’s plans are a lot simpler. They will manufacture the space planes and sell them to space tourism companies. Assuming a similar pattern to classical aerospace business models, there could be many tourist carriers using the same Astrium-class spacecraft.

“It will develop towards a classical aeronautical business model. Someone will build the planes; somebody will operate them; somebody will sell the tickets; somebody will provide the accommodation – like any tourism.” – Robert Laine, chief technical officer (CTO) of EADS (Astrium)

Speaking in London at the Institution of Engineering and Technology, delivering the 99th Kelvin Lecture, Robert Laine, CTO of EADS (Astrium), outlined Astrium’s plan for the future. According to Laine, Astrium’s new space planeÂ is developing quickly, and the aerodynamic structure is undergoing final wind tunnel tests. The Romeo rocket engine has been successful in advanced tests, and has run for 31 seconds. To provide the craft with enough boost to leave the Earth’s atmosphere, it will need to burn for 80 seconds. The oxygen-methane fuel engine will give the spacecraft a high enough velocity (1 km/s) to exit the atmosphere.

About 50% of the starting mass of the plane will be fuel. The preliminary design will have enough room for five people – four tourists, one pilot.

Ultimately the Astrium design is hoped to have a lifetime of 10 years and will be easy to maintain. What makes this design even more interesting is its conventional take-off and landing, plus there is no requirement for a launch vehicle. The craft could be used in conventional airports, but Astrium believes custom-made spaceports will be a better solution to avoid busy air traffic. Laine believes that the Astrium spacecraft can be fully operational within five years of a financing deal being signed.

Although weightlessness is only likely to be three minutes long, the two hour round trip will certainly be exhilarating. The three-G acceleration as the rocket engines kick in will be worth the trip alone!

Keep an eye on Astrium, they may be a close second to manufacturing a space tourist craft after Richard Branson…

Source: BBC

Posted on March 18, 2008December 26, 2015 by Ian O'Neill
Why are Saturn’s Rings Disappearing?

Astronomers have noticed a change on Saturn. The planet’s rings are getting thinner and thinner and the detailsÂ in the dark bandsÂ are getting harder to observe. What’s more, at this rate, Saturn’s rings will have completely vanished by Sept. 4, 2009!

But don’t pack up your telescopes quite yet, there’s no reason to be alarmed. This phenomenon occurs every 14 to 15 years and the explanation is down to an astronomical optical illusion called “ring plane crossing”…

In 1612, Galileo noticed something was awry with the beautiful gas giant. The distinctive rings of Saturn were shrinking until he was unable to see them any more. The situation was so strange that Galileo even stopped observing the planet (most likely through frustration!). He had discovered the rings two years earlier and was instantly entranced by them. He once wrote to his Medici patrons on the discovery in 1610: “I found another very strange wonder, which I should like to make known to their Highnessesâ€¦” so you can imagine his confusion when the rings slipped out of view.

Ring plane crossings occur periodically when the tilt and position in Saturn’s orbit combine to allow astronomers a unique side-onÂ view of the rings. Far from being a loss, looking at the paper-thin rings side-on will remove the glare from the bright rings giving astronomers a superb opportunity to see the icy moons orbiting close to Saturn. Also, Saturn’s strangely blue north pole should be observable. Saturn is better known for its brown-golden clouds of gas, but in high latitudes, these clouds thin out to reveal a blue dome. Cancelling the light from Saturn’s rings may provide a perfect environment to see the blue from Earth and to view the points of bright light shining off the small moons.

So dust off those telescopes, a once-in-14-year astronomical opportunity is approaching…

Source: NASA

Posted on March 18, 2008December 26, 2015 by Nicholos Wethington
Peruvian Meteorite May Rewrite Impact Theories

On September 15th of last year, a meteorite impacted the Earth near the town of Carancas in Peru. The story made worldwide headlines when hundreds of people who flocked to see the crater reported getting ill. As it turned out, there were no mysterious space illnesses plaguing the population; the super-hot meteorite likely vaporized arsenic-containing water that was near the surface of the impact site, and onlookers and investigators breathed in the noxious gas. The meteorite is again in the spotlight, though not for making people sick.

Researchers estimate from their analysis of the crater that the meteorite was of a rocky composition, and that it impacted the ground at a whopping 15,000 miles (24,150 kilometers) per hour. That is really fast for a stony meteorite! It is calculated to have been between .2 and 2 meters at the point of impact, and upwards of 3 meters when it entered the atmosphere.

â€œNormally with a small object like this, the atmosphere slows it down, and it becomes the equivalent of a bowling ball dropping into the ground. It would make a hole in the ground, like a pit, but not a crater. But this meteorite kept on going at a speed about 40 to 50 times faster than it should have been going.â€ said Peter Schultz, professor of geological sciences at Brown University, who presented the findings of his travels to the impact site at the 39th annual Lunar and Planetary Science Conference in Texas last week. Schultz collaborated on his research with a team of scientist from Brown University, Peru and Uruguay.

Stony meteorites â€“ called chondrites â€“ generally break up in the atmosphere and impact the ground at rather slow speeds. In fact, most of the objects that enter Earth’s atmosphere end up never hitting the ground because the gases are so thick that the heat caused by air compression vaporizes them.

Schultz and his team think the Carancas meteorite may have initially broken up and then reformed in such a way as to make it more aerodynamic, allowing it to bullet through the atmosphere instead of being braked by the friction with the gases in our atmosphere. As opposed to dissipating and burning up like other chondrites, the meteorite landed as one large chunk.

This contradicts the conventional theory that small, rocky asteroids either can’t impact at all, or create only small impact pits. If the new theory is correct, we may have to rethink the history and influence of meteorite impacts on the Earth, as well as consider what kind of damage they are capable of doing in the future.

Source: Brown University News Release

Posted on March 18, 2008December 26, 2015 by Tammy Plotner
Celebrate Sun-Earth Day 2008 on March 20

Over the past seven years, NASA Sun-Earth Connection Education Forum has sponsored and coordinated education and public outreach events to highlight NASA Sun-Earth Connection research and discoveries. Their purpose is to interest school students and the general public to participate in programs that occur throughout the year and the kickoff is about to begin. This year’s main event will be on March 20, 2008.

Sun-Earth Day isn’t strictly limited to this single day. It’s a combination of programs and events throughout the year and celebrated this year on March 20. Middle schools are invited to participate, learn about solar science, solar energy and career choices. Following the events will prepare participants to watch a total solar eclipse on August 1, 2008 via a live web cast from China!

A wealth of website related resources provided by a collaboration of partners that include science centers and museums around the world, the Exploratorium, NASA Connect, Sun-Earth Connection missions and others, offer up awesome experiences like watching a Polar Sunrise. All you need is an Internet connection to visit the unscripted and unpredictable look into some of the latest information on Space Weather, Sun-Earth Day, Solar Week and the new ‘student based’ Space Weather Action Center at NASA Edge where they’re currently featuring programs on “The Sun-Earth Connection” and “Magnetospherence”. Visit the Solar Week website for educational classroom activities and games geared for upper elementary, middle and high school students with a focus on the Sun-Earth connection. Students learn about solar eclipses, sunspots, and solar storms through a series of activities, games, and lessons.

Get involved in Public Outreach! You don’t have to be in a classroom to share your love of astronomy and the Sun-Earth connection. Materials are available that have been specifically designed for you, the museums, planetaria, parks, youth clubs, and educators from community organizations around the globe. A wealth of Hands-On Sun-Earth Day Activities are available. Why not try enabling an idle computer at work with the Sun-Earth Viewer? Take the time to read a Sun-Earth Day Book to your children or grandchildren. It’s as easy as visiting the site and taking few moments to download.

Do you want more? Learn about the aurora at Dancing in the Night Sky or how NASA engineers and researchers use data analysis and measurement to predict solar storms, anticipate how they will affect the Earth, and improve our understanding of the Sun-Earth system at Having A Solar Blast. Don’t forget other great resources like NASA TV or music at Rock Our World. Visit the download site and pick up great movies like “Introduction to the STEREO Mission – Solar Terrestrial Relations Observatory” and “Blackout: The Sun-Earth Connection”.

No matter what you choose to do, Sun-Earth Day is a great time to share with others and have fun!

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