Universe Today

March 10, 2008December 26, 2015 by Fraser Cain

Cosmic Neutrinos, the End of the Dark Ages, and Inflation: 5 Years of WMAP Data

We now know the Universe is around 13.7 billion years old. But just a few years ago, cosmologists had no idea, putting the range around 10-20 billion years old – some even thought it could be 100 billion years old. We can thank NASA’s Wilkinson Microwave Anisotropy Probe for giving us the concrete answer. And now, NASA released 5 years of data collection, telling astronomers more about the earliest moments in the Universe, the background sea of cosmic neutrinos and the end of the Dark Ages.

WMAP looks at the Universe with microwave eyes. It may sound like a strange wavelength to use when witnessing the highest energy event ever – the aftermath of the Big Bang. But there’s a trick, over the billions of years of time, the Universe has been expanding. Radiation has had its wavelengths stretched out across the billions of light-years of distance and expansion. The visible light after the Big Bang has become a diffuse glow of microwaves in all directions.

Astronomers use WMAP to study the subtle temperature variations in this microwave background radiation to understand what the Universe looked like at the very beginning.

This 5th anniversary release of data is the icing on the cake, with some significant new findings.

First up, WMAP found evidence for a background sea of cosmic neutrinos that permeate the background of the Universe. These almost weightless sub-atomic particles zip around at nearly the speed of light. In fact, there are millions passing through your body right now, blasted out from the Sun. They don’t interact with anything, so they don’t cause any harm. In fact, a neutrino could probably make it through several light years of solid lead without being stopped.

So, in addition to the solar neutrinos there seem to be a sea of background neutrinos, generated during the Universe’s early development.

The second big discovery is clear evidence that the first generation of stars took more than a half-billion years to create a cosmic fog.

“We now have evidence that the creation of this fog was a drawn-out process, starting when the universe was about 400 million years old and lasting for half a billion years,” said WMAP team member Joanna Dunkley of the University of Oxford in the U.K. and Princeton University in Princeton, N.J. “These measurements are currently possible only with WMAP.”

Finally, WMAP put in tight constraints on the concept of “inflation”. This was an incredible burst of growth in the first trillionth of a second of the Universe. This period of inflation left ripples in the fabric of space, detectable in the cosmic microwave background radiation.

All in all, it’s been a good 5 years for WMAP.

Original Source: NASA News Release

March 10, 2008December 26, 2015 by Nancy Atkinson

South Korean Astronauts Switched After Rule Infraction

When it comes to following space agency rules, Russia stands firm. The man who was going to be the first South Korean in space has now been grounded for violating Russian security protocol and will be replaced by a female biotechnology engineer, the South Korean science ministry said on Monday. Ko San, 31, was dropped from the April 2008 flight to the International Space Station on a Russian Soyuz spacecraft. He is now the backup for the mission after he removed sensitive material from a Russian space training center. Ko, a technology researcher is being replaced by Yi So-yeon, 29, who is finishing her doctorate in bioengineering.

“The Russians emphasized the importance of abiding by the rules, as even small mistakes can bring about grave consequences in space,” a South Koren official said at a news conference, adding Ko appeared to have made innocent mistakes.

The Russian authorities said Ko took a book out of the center without permission and sent it to his home in South Korea in September. Ko later returned the book, explaining he accidently sent it home together with other personal belongings.

In February, Ko again violated regulations by getting a book from the center through a Russian colleague, and it was material he was not supposed to read. Officials did not give details about the book’s contents, but South Korean officials portrayed both of his infractions as minor.

“The Russian space agency has stressed that a minor mistake and disobedience can cause serious consequences,” a south Korean official told reporters.

Ko will remain at the Russian space center and continue training. The official did not say if Ko would possibly go to space on a future flight.

Yi, 29, will work aboard the International Space Station for about 10 days with three other cosmonauts as well as American station commander Peggy Whitson and flight engineer Garrett Reisman. Yi will conduct scientific experiments, according to a ministry statement.

The mission will make South Korea the world’s 35th country and Asia’s sixth to send an astronaut into space.

The two South Koreans were selected from a list of more than 36,000 candidates.

Original News Source: Reuters, AP

March 10, 2008December 26, 2015 by Fraser Cain

Passing Through the Plumes; Enceladus Flyby on Wednesday

Mark your calendars, this is going to be an amazing ride. NASA’s Cassini spacecraft is going to make a flyby of Saturn’s moon Enceladus on Wednesday, March 12, 2008. And this time, the spacecraft is going to fly right through the mysterious geysers of water ice blasting out of the moon’s Southern pole. At its closest approach, Cassini is going to get within 50 km (30 miles) of the surface. Now that’s close!

It was on a previous flyby that Cassini turned up evidence for the ice geysers in the first place. Images of the moon showed that huge plumes of water ice are pouring out of deep cracks around the moon’s southern pole. It’s believed that tidal interactions between Enceladus and Saturn are heating the moon’s interior. That heat has to escape, and this is how.

The particles really blast out of Enceladus, traveling at 1,285 km/h (800 miles per hour). The plumes expand out to distance three times as large as the moon itself. And this material even seems to be contributing to one of Saturn’s rings.

So on Wednesday, scientists will have an opportunity to get some of their questions answered. Cassini will fly on a trajectory that takes it through the edge of the plumes. At this point, it will be about 195 km (120 miles) above the surface. It will get even closer, skimming the moon at just 50 km (30 miles).

Although there will be pretty pictures, the main instruments used will be Cassini’s particle analyzers. These will study the composition of the plumes themselves – “sniffing and tasting” them.

“There are two types of particles coming from Enceladus, one pure water-ice, the other water-ice mixed with other stuff,” said Sascha Kempf, deputy principal investigator for Cassini’s Cosmic Dust Analyzer at the Max Planck Institute for Nuclear Physics in Heidelberg, Germany. “We think the clean water-ice particles are being bounced off the surface and the dirty water-ice particles are coming from inside the moon. This flyby will show us whether this concept is right or wrong.”

This will actually be the first of four Cassini/Enceladus flybys this year, and so if scientists don’t see what they’re looking for, there will be other chances.

Original Source: NASA/JPL Flyby Page

March 10, 2008December 26, 2015 by Fraser Cain

Planets Might Actually Shape Planetary Nebulae (plus a gallery)

Despite the name, a “planetary nebula” has nothing to do with planets. They were given the confusing name 300 years ago by William Herschel because they looked like planets in their early, rudimentary telescopes. They’re really the glowing shells of gas and dust puffed out by stars nearing the end of their lives. But wait, planets might be responsible after all.

And as a special bonus for actually reading this article, I’ll treat you to a gallery of beautiful planetary nebulae.

Astronomers at the University of Rochester have announced that low-mass stars, and maybe even super-Jupiter-sized planets might actually be responsible for the beautiful puffy nebulae. Their research appears in the latest editions of the Astrophysical Journal Letters and Monthly Notices of the Royal Astronomical Society.

Most medium-sized stars, like our own Sun, will end their lives as planetary nebulae. Even though the star has lived for billions of years, this stage just lasts several tens of thousands of years. The star runs out of fuel, its core contracts, and it ejects the outermost layers of its atmosphere into space. The expanding shell can be spherical in shape, but its often twisted and elongated.

Astronomers used to think that powerful magnetic forces shape the nebula. But maybe the low-mass companion star or super-Jupiter planet might be providing the gravity that warps and distorts the shape of the nebula.

The Rochester team studied the interplay between a companion star or planet and the expanding envelope of material given off by a dying star. When the star or planet is in a very wide orbit, its gravity drags some of the envelope material around on its orbit. This creates spiral waves of nebula material that expand out from the star, bunched up by interactions with the star or planet.

There could be an entirely different effect when the companion orbits within the envelope of the dying star. It could spin up material more quickly, ejecting it into a large disk around the star. It might also work with the star’s magnetic field to force material into jets out the poles.

Of course, a companion orbiting too close to the parent star might get shredded into a debris disk orbiting the dying star. And this disk could interfere with the nice smooth expansion of stellar material.

It might be that companion stars and large planets might be responsible for the beautiful shapes we see.

Planets might be needed for planetary nebulae after all.

Original Source: University of Rochester News Release

March 10, 2008December 26, 2015 by Fraser Cain

Discovery of the Earth’s Inner, Inner Core

The traditional view of the Earth’s interior has the crust (where we live), the upper and inner mantle, the outer core, and the inner core; wrapped around each other like layers of an onion. But now textbooks will need to be revised. It turns out there’s an inner, inner core.

The core of Earth is known to have an inner core of solid iron about 2,400 km (1,500 miles). Wrapped around that is a fluid outer core that reaches 7,000 km across (4,300 miles). As the solid core rotates inside the fluid core, it generates the magnetic field that helps us navigate, and protects the planet from harmful radiation and the effects of the solar wind.

Geologists from the University of Illinois at Urbana-Chamaign have been probing the interior of the planet, trying to get a better sense of its structure. And that’s harder than it sounds. You can’t just look down through thousands of km of solid rock.

There were using the natural waves that pass through the Earth after earthquakes shake on the surface. The waves are bent and reflected as they pass through the various layers inside the planet.

The team was specifically studying how the waves were affected as they passed through the solid inner core and were surprised to see that it wasn’t a uniform sphere of iron.

Instead, the seismic waves clearly showed that there’s an additional layer at a diameter of 1,180 km (733 miles), which makes this less than half the diameter of the inner core.

This is the Earth’s inner, inner core.

So what is it? Here’s what the lead scientists, Xiaodong Song had to say:

“Our results suggest the outer inner core is composed of iron crystals of a single phase with different degrees of preferred alignment along Earthâ€™s spin axis,” Sun said. “The inner inner core may be composed of a different phase of crystalline iron or have a different pattern of alignment.”

It’s still iron, just not in the same crystalline structure. Perhaps its time to give the layers new names, inner inner core doesn’t quite work for me.

Original Source: University of Illinois News Release

March 10, 2008December 26, 2015 by Fraser Cain

Astronomy Cast is Liveblogging All this Week from Houston

You might have forgotten, but the big Lunar and Planetary Society Conference is happening all this week in Houston – from these conferences come mountains of space news. Once again, the intrepid blogging team is bringing the conference to you (sort of live), with articles, audio, video, and photographs. Pamela and Rebecca are at the conference, and at the same time, we’ve got Scott Miller over at Cape Canaveral to cover the next launch of the space shuttle. And I’m back and Mission Control: Vancouver, reporting on all the news pouring out that they’ll be too busy to cover. It should be a very interesting week.

I’ll have reports here on Universe Today, but the best place is to go to our Astronomy Cast LIVE blog, where you’ll see posts from all the contributors.

Click here to visit Astronomy Cast LIVE.

And if you want to meet Pamela and Rebecca, there’s going to be having another listener meetup on Tuesday, 8pm at San Lorenzoâ€™s. Here’s a link to a map.

March 10, 2008December 26, 2015 by Fraser Cain

Podcast: How Big is the Universe?

Weâ€™re ready to complete our trilogy of discovery about the universe. Weâ€™ve learned that it has no center; rather everywhere is its center and nowhere. We discovered that the universe seems to be flat. It’s not open, it’s not closed, it’s flat. If that doesnâ€™t make any sense, you need to listen to the previous show because thereâ€™s no way I could give that an explanation.

So now we want to know: â€œHow big is it?â€ Does it go on forever or is it finite in scale? How much of it can we see?

Click here to download the episode

How Big is the Universe? – Show notes and transcript

Or subscribe to: astronomycast.com/podcast.xml with your podcatching software.

March 10, 2008April 26, 2016 by Fraser Cain

Digg Mars Madness

If you’re a member of the social network website Digg.com, read this. Otherwise, ignore this post.

As you know, Nancy wrote a cool article last week about a one-way, one-person trip to Mars. Digg.com picked up the story, but for some reason, it has showed up several times in different locations, so the vote is getting totally split up. Could you take a second and Digg the most popular one, here?

How About a One-Way, One-Person Trip to Mars

I’m not kidding, here are the others (but don’t Digg them).

Here.
Here.
Here.
Here.
Here.
And here.

March 9, 2008April 26, 2016 by Ian O'Neill

Jupiter has Van Allen Belts too, Just Bigger; Implications for Space Weather Prediction

Jupiter has a powerful magnetic field 20,000 times stronger than the Earth’s. It is therefore of no surprise that the highly energetic and damaging particles flying around in the Earths Van Allen Belts can be found within Jupiter’s magnetosphere too. But are the mechanisms energizing these particles the same for both planets? New research suggests that the magnetospheres of Jupiter and Earth may have more in common than previously thought…

As previously reported on Universe Today, there is a possible source to the magnetospheric “hiss” that energizes protons and electrons within the Earth’s Van Allen Belts. The discovery that low frequency “chorus” waves propagating through the upper atmosphere evolve into waves that can interact with charged particles is significant in that it helps to solve a 40 year debate as to where these waves come from. Now, the nature of Jupiter’s highly energetic particles trapped in its strong magnetic field has been brought into question.

The Galileo spacecraft (pictured) measured radio wave activity inside the magnetosphere as it orbited the gas giant over eight years. According to the scientific collaboration including researchers at the British Antarctic Survey (BAS), University of California, Los Angeles (UCLA), and the University of Iowa (UI), similar low frequency radio waves may be responsible for electron energization in the Jovian high energy particle belts as in the terrestrial Van Allen Belts.

Although details on the source of Earth’s “chorus” waves are sketchy (we know they originate outside of the plasmasphere surrounding Earth and evolve into a radio wave “hiss” inside the Van Allen Belts), the source of low frequency radio waves around Jupiter comes from the interactions between the moon Io and the Jovian magnetic field.

“On Jupiter, the waves are powered by energy from volcanoes on the moon Io, combined with the planetâ€™s rapid rotation â€“ once every 10 hours. Volcanic gasses are ionized and flung out away from the planet by centrifugal force. This material is replaced by an inward flow of particles that excite the waves that in turn accelerate the electrons.” – Dr Richard Horne, lead author of research, British Antarctic Survey (BAS).

The interaction of Jupiter’s moons with its atmosphere is highlighted when analysing the pattern of the polar auroral regions on the planet. As the magnetic field is so strong on Jupiter, massive regions of bright emission can be seen in the UV wavelengths (pictured top). This is emission from huge auroral displays as highly energetic particles funnel down magnetic flux and interact with Jupiter’s atmosphere (similar to Earth’s auroral displays, only much bigger). There are some strange patterns in the auroral “crown” – “footprints” of the Jovian moons, Io, Ganymede and Europa. The moons emit particles which get directed down to Jupiter by the gas giant’s magnetic field. These footprints appear as little spots in Jovian polar regions, rotating with the moons as they pass through the magnetosphere.

By far the strongest influence on Jupiter’s magnetosphere, Io is constantly erupting with material, firing it through the Jovian magnetic field. Thanks to Galileo data, it appears this fastÂ orbiting moon generates low frequency radio waves, driving the high energy particles trapped within Jupiter’s plasmasphere through wave-particle interactions.

“For more than 30 years it was thought that the electrons are accelerated as a result of transport towards Jupiter, but now we show that gyro-resonant wave acceleration is a very important step that acts in concert.” – Dr Horne

These results will have a huge impact on space weather forecasting. As the Sun erupts during periods of heightened solar activity (i.e. during “solar maximum”), the reaction of the Earth’s plasmasphere is critical to understanding the quantities of damaging high energy particles that may influence space missions, damaging satellites and causing harm to astronauts. Looking into Jupiter’s huge magnetosphere will aid understanding of our own magnetosphere, hopefully improving solar storm predictions.

Source: British Antarctic Survey

March 9, 2008December 26, 2015 by Ian O'Neill

ESA Automated Transfer Vehicle Blasts Into Space (Video); See the ATV Mission Animation

The European Space Agency’s (ESA) Automated Transfer Vehicle (ATV) has been successfully launched into orbit. The ATV, also known as “Jules Verne”, is Europe’s largest and most complex spaceship ever. Weighing in at 20 tons, the ATV needed a big push to get it into space, so the largest member of the Arianespace-built rocket family was called into use, the Ariane-5. The unmanned ATV is now en-route to the International Space Station, to make some deliveries…

(Including a cool little animation of the entire mission courtesy of ESA.)

Launched from French Guiana (South America) at 0403 GMT, March 9th, the Ariane-5 rocket lifted the heavy vehicle into orbit to send cargo, propellant, water and oxygen to the International Space Station (ISS). This is the largest payload ever lifted by Arianespace, and the new Ariane-5 performed excellently. After 66 minutes from blast-off, the launch was declared a success as the ATV separated from its Ariane-5 boosters to begin its mission.

The ATV is a unique spacecraft. It has been called a “barge”, “truck”, “freighter”, “tug” and its mission is pretty unglamorous. Primarily it will take about 7.5 tons of supplies to the ISS, docking (automatically) with the Russian service module. Then, it will act as a waste disposal module for six months, remaining attached to the station, being filled with rubbish from the stations crew. When full with over six tons of trash, it will separate and then kill itself by falling through the Earth’s atmosphere, insuring all the waste gets incinerated. It will be the ultimate single-use product.

The ATV now has to hang around in an orbital holding pattern to wait for Space Shuttle Endeavour to launch (on March 11th), dock and then leave the ISS on March 24th before it can approach the station. See “Traffic Jam at the Space Station” to find out how busy it’s getting up there.

Source: ESA