Universe Today

August 21, 2010December 24, 2015 by Tammy Plotner

Observing Spotlight – Dropping In On Jupiter…

Parallel/Cross-Eye 3D Image - Click For Full Size

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“Now that she’s back in the atmosphere, with drops of Jupiter in her hair…” Oh! Hey, there! Come on over and have a seat. Yeah, I really like that “Train” song, too. While the Moon is putting the brakes on deep sky observing, why don’t you take a look though the magnificent eye of the 9″ TMB refractor of Dietmar Hager and we world-wide friends can spend a little quality time together with Jupiter.

Here… You look through the eyepiece of a little telescope for awhile and I’ll tell you some of the things we know about this giant planet.

What’s that you say? Yes. Jupiter is big… Big enough to hold the mass of 1,000 Earths and about 1/10 the size of our Sun. Its a heavy-weight, too… But, believe it or not, Jupiter’s density is only about 1/4 of that of Earth’s. Scientists think this means the giant planet consists mostly of hydrogen and helium around a core of heavy elements. That means Jupiter more closely resembles a sun instead of a planet! Yeah… It’s hot there, too. As a matter of fact, Jupiter is putting out twice as much heat as it receives from Sol. Near the core temperature may be about 43,000 degrees F (24,000 degrees C)… Even hotter than the surface of the Sun. Hot enough to get a burn? Darn right. Those subtle tones of red and brown are chemical reactions much like what happens when we humans get a sunburn.

I see you smiling in the dark. Are you starting to notice details Jupiter’s cloud bands? Even a small telescope shows these areas called “zones”. This is where chemicals have formed colorful layers of clouds at different heights. The white belts are made of crystals of frozen ammonia and they are positioned much higher than the dark belts. Of course, you know all about the “Great Red Spot”, but sometimes it’s pretty hard to see unless you know when to look. Jupiter makes a complete rotation in about 10 hours, so even if you can’t see something right now – you can wait awhile and it will come around.

Speaking of coming around, did you notice how close one of Jupiter’s moon is getting to the edge of the planet? Then keep watching because we’re about to see a transit happen. Jupiter has at least 60 moons, but 4 of them are bright and very easy to see even in binoculars. They were discovered by Galileo, and that’s why you’ll sometimes hear them called the “galiean moons”. When they zip around behind Jupiter in their orbit, it’s called a occultation – but when they go in front of the planet from our point of view, it’s called a tranist. The really fun part is that you can not only see the little moon going across the surface, but a few minutes later? You can see the shadow, too! Here’s a little bit of magic from another friend of ours named Sander Klieverik.

Jupiter 16-04-2004 Sander Klieverik — Click to start animation...

Isn’t that just the coolest? You’re going to be hearing a lot about Sander’s work here in the near future. And there’s going to be a great Jupiter event he wants to make sure you know about!

“On October 31, 2010 Europa and Ganymede will simultaneously cross the cloud tops of Jupiter from 02:26 till 03:21 UT as do their shadows from 04:17 UT till 07:00 UT. Timing of entrance of the first moon, Ganymede will be around 00.20 UT, following by Europe at 02:26 UT. The first shadow will appear 04:09, quickly followed by Europe’s shadow at 04:16. Two shadows in very close proximity should be a very beautiful view! Circumstances are favourable as Jupiter has a visual diameter of around 48 arc seconds, being a month after opposition in which Jupiter reached almost 50 arc seconds (minimum 33″). For the non-astronomers, when a planet is in opposition it is roughly closest to the Earth at this point of its orbit, making it appear bigger and brighter. At that moment it is visible almost all night, rising around sunset, culminating around midnight and setting around sunrise.”

In the meantime, why don’t you keep practicing timing galiean events and seeing them? Here’s a handy Jupiter Moon Tool, and Sander has also prepared a Jupiter Almanac as well!

“But tell me, did the wind sweep you off your feet? Did you finally get the chance to dance along the light of day… And head back to the Milky Way? And tell me, did Venus blow your mind? Was it everything you wanted to find? And did you miss me 1hile you were looking for yourself out there?”

Now, quit bogarting that eyepiece… It’s my turn!

Many thanks to the one and only Dietmar Hager, Jupiter Video courtesy of Northern Galactic and the up and coming Sander Klieverik’s “AstronomyLive”. Song lyrics – “Drops of Jupiter” are from the artists “Train”. Let’s keep on rockin’ the night!

August 21, 2010December 24, 2015 by Steve Nerlich

Astronomy Without A Telescope – A Universe Free Of Charge?

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If there were equal amounts of matter and anti-matter in the universe, it would be easy to deduce that the universe has a net charge of zero, since a defining ‘opposite’ of matter and anti-matter is charge. So if a particle has charge, its anti-particle will have an equal but opposite charge. For example, protons have a positive charge – while anti-protons have a negative charge.

But it’s not apparent that there is a lot of anti-matter around as neither the cosmic microwave background, nor the more contemporary universe contain evidence of annihilation borders – where contact between regions of large scale matter and large scale anti-matter should produce bright outbursts of gamma rays.

So, since we do apparently live in a matter-dominated universe – the question of whether the universe has a net charge of zero is an open question.

It’s reasonable to assume that dark matter has either a net zero charge – or just no charge at all – simply because it is dark. Charged particles and larger objects like stars with dynamic mixtures of positive and negative charges, produce electromagnetic fields and electromagnetic radiation.

So, perhaps we can constrain the question of whether the universe has a net charge of zero to just asking whether the total sum of all non-dark matter has. We know that most cold, static matter – that is in an atomic, rather than a plasma, form – should have a net charge of zero, since atoms have equal numbers of positively charged protons and negatively charged electrons.

Stars composed of hot plasma might also be assumed to have a net charge of zero, since they are the product of accreted cold, atomic material which has been compressed and heated to create a plasma of dissociated nuclei (+ve) and electrons (-ve).

The principle of charge conservation (which is accredited to Benjamin Franklin) has it that the amount of charge in a system is always conserved, so that the amount flowing in will equal the amount flowing out.

Apollo 15's Lunar Surface Experiments Package (ALSEP). The Moon represents a good vantage point to measure the balance of incoming cosmic rays versus outgoing solar wind.

An experiment which has been suggested to enable measurement of the net charge of the universe, involves looking at the solar system as a charge-conserving system, where the amount flowing in is carried by charged particles in cosmic rays – while the amount flowing out is carried by charged particles in the Sun’s solar wind.

If we then look at a cool, solid object like the Moon, which has no magnetic field or atmosphere to deflect charged particles, it should be possible to estimate the net contribution of charge delivered by cosmic rays and by solar wind. And when the Moon is shadowed by the tail of the Earth’s magnetosphere, it should be possible to detect the flux attributable to just cosmic rays – which should represent the charge status of the wider universe.

Drawing on data collected from sources including Apollo surface experiments, the Solar and Heliospheric Observatory (SOHO), the WIND spacecraft and the Alpha Magnetic Spectrometer flown on a space shuttle (STS 91), the surprising finding is a net overbalance of positive charges arriving from deep space, implying that there is an overall charge imbalance in the cosmos.

Either that or a negative charge flux occurs at energy levels lower than the threshold of measurement that was achievable in this study. So perhaps this study is a bit inconclusive, but the question of whether the universe has a net charge of zero still remains an open question.

Further reading: Simon, M.J. and Ulbricht, J. (2010) Generating an electrical potential on the Moon by cosmic rays and solar wind?

August 21, 2010December 24, 2015 by Jason Rhian

Desert RATS – On The Move

NASA's Desert RATS will conduct field tests at the end of this month.

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For some fourteen years now NASA‘s Desert Research and Technology Studies (Desert RATS) team has been testing out the viability of many of NASA’s vehicles, space suits, habitats and robotic systems in extreme environments. Like their durable name-sake, the Desert RATS have proven to be resilient and flexible, adapting to the changing NASA environment. When it was announced that NASA would move away from the Constellation Program and toward other objectives such as asteroids and possibly Mars – the Desert RATS picked up the challenge and modified their regimen to reflect this change.

Testing this year will take place from Aug. 31 until Sept. 15 and will shakedown many new design concepts. The former Electric Lunar Rovers, now dubbed Space Exploration Vehicles will be tested at the site requiring simulated astronauts to live in these vehicles for a week.

No Desert RATS expedition would be incomplete without some incredible robots to assist their human companions. There are the Tri-ATHLETEs (Terrain Hex-Legged Extra-Terrestrial Explorer) – these wheeled, spidery creations have six independent ‘legs’ each with a wheel at the base and can be fitted with different ‘tops” for each mission. Robonaut 2, one of NASA’s new robotic rock-stars, has been converted into a four-wheeled variant dubbed Centaur 2 and will be tested this year. This variation could be a potential mode of transport for NASA.

However, this year’s rotation is all about the “hab.” The Habitat Demonstration Unit (HDU) Project is an inter-agency project consisting of NASA architects, scientists and engineers. These groups are working to develop living quarters, workspaces, and laboratories for future space missions, working under the “build a little – test a little” philosophy. This area will serve as a laboratory, a place for maintenance and a staging area in the event of a medical emergency.

Robonaut-1 is seen here in its Centaur configuration. Photo Credit: NASA/Joe Bibby

“This allows us to have far greater flexibility,” said Tracy Gill, NASA’s Deputy Project Manager for the habitat element of this project. “These habitats are currently in the process of being developed further to make them even more adaptable.”

NASA is working with the National Space Grant Foundation to develop an inflatable “loft” that will be attached to the HDU. This will mean that astronauts won’t have to don a space suit to travel from their living quarters to where they work – they would simply have to go “upstairs.” In an effort to promote science, technology, engineering and math (known as STEM) in college-age students, the X-Hab Academic Innovation Competition is working to sponsor development of these inflatable habitat concepts. The goal is for senior and graduate-level design students to design, manufacture, assemble, and test an inflatable loft that will be integrated on top of an existing NASA built hard shell prototype.

As with any year the Desert RATS test out new concepts, this year promises to display many futuristic ideas that one day may be used in the real world(s). This year is slightly different however, in that the elements being tested are designed to be readily adaptable toward whatever NASA will eventually be called to do. During the Apollo era, astronauts were trained by “the King” – Farouk El-Baz. El-Baz worked with the astronauts so that they would be intimately familiar with the lunar surface, that they had the training and tools to get the job done. These annual event – would make “the King” – proud.

August 20, 2010December 24, 2015 by Nancy Atkinson

NASA Managers Approve Additional Shuttle Flight

Atlantis launches on its last scheduled mission. Image credit: Alan Walters (awaltersphoto.com) for Universe Today

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While the final decision on adding an additional shuttle flight rests on the political process, today NASA managers approved adding the STS-135 mission, from a safety and logistics standpoint. If Congress gives final approval for funding one more shuttle mission beyond the two that are currently on the manifest, space shuttle Atlantis would be targeted to launch on June 28, 2011. The STS-135 mission – if not needed as a “Launch on Need” rescue flight for STS-133 or STS-134, would have a 4-member crew and carry a fully-loaded multi-purpose Logistics Module (MPLM) and a Lightweight Multi-Purpose Carrier to the International Space Station.

NASA’s Aerospace Safety Advisory Panel approved adding the flight from a safety standpoint. Having a crew of four means the crew – if stranded on the ISS – could stay on the space station and rotate coming back to Earth on the Soyuz spacecraft that serve as rides home/rescue vehicles , and NASA would not need another shuttle on standby for a rescue.

Originally, the Senate version of NASA’s 2011 budget included funding for an additional shuttle mission but the House version did not. However, NASASpaceflight.com reported that “The House authorization bill added the additional flight to mirror the Senate bill,” adding that the two bills differ in how the flight would be paid for.

Atlantis will be processed for the STS-335 Launch On Need mission, and the final decision on whether STS-135 becomes a reality remains to be seen. Stay tuned!

Source: NASASpaceflight.com

August 20, 2010December 24, 2015 by Nancy Atkinson

Help NASA Choose Wakeup Music for Final Shuttle Missions

It’s the one kind of cheesy thing we all listen for each day of a shuttle mission: the wake up song. With only a few space shuttle missions left on the manifest, NASA has decided to enlist the help of the public to help choose the songs that will wake up the astronauts for STS-133 – currently scheduled for a November 1, 2010 launch — and STS-134, slated to launch on February 26, 2011. Not only can you choose from previously played popular songs, but those of you musically inclined can write a song and submit it.

See the NASA website for more details.

The deadline is January 10, 2011.

August 20, 2010January 20, 2016 by Nancy Atkinson

Stunning Flyover Videos of Saturn’s Moons

Saturn’s moons as you’ve never seen them before! By day, Dr. Paul Schenk works at the Lunar and Planetary Institute mapping the topography and geology of the moons of Saturn and Jupiter, as well as the icy bodies of the outer solar system. But because “it’s just plain cool,” he has created some flyover videos of Saturn’s satellites, using data from the Cassini spacecraft. Very cool, indeed! Above is a close-up, 3-D look at the walnut-shaped moon Iapetus. Scientists don’t know why there is a ridge along the moon’s equator, but in 2007, Cassini acquired a strip of color and stereo images along the ridge, and Schenk has created a flyover which shows the contrast in color and topography. There are “sharp peaks 15 to 20 kilometers above the surrounding dark cratered plains,” Schenk writes. “These are among the highest peaks in the Solar System. Patches of bright pure water ice can be seen flanking these dark peaks, which have the brightness of soot.”

And there’s more! Below is one of my favorites from Schenk’s collection of flyover videos, 3-D views of Inktomi, a very young crater on the moon Rhea.

Continue reading “Stunning Flyover Videos of Saturn’s Moons”

August 19, 2010April 26, 2016 by Nancy Atkinson

Carnival of Space #167

This week’s Carnival of Space is hosted by The Space Tweep Society! This is the first time the Tweeps have hosted the Carnival, so go check out all the things they do to promote space exploration STEM education.

Click here to read the Carnival of Space #167.

And if you’re interested in looking back, here’s an archive to all the past Carnivals of Space. If you’ve got a space-related blog, you should really join the carnival. Just email an entry to [email protected], and the next host will link to it. It will help get awareness out there about your writing, help you meet others in the space community – and community is what blogging is all about. And if you really want to help out, let Fraser know if you can be a host, and he’ll schedule you into the calendar.

Finally, if you run a space-related blog, please post a link to the Carnival of Space. Help us get the word out.

August 19, 2010December 24, 2015 by Nancy Atkinson

Satellite Data Show Plant Growth is Declining on Earth

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One idea about climate change suggested that higher temperatures would boost plant growth and food production. That may have been a trend for awhile, where plant growth flourished with a longer growing season, but the latest analysis of satellite data shows that rising global temperatures has reached a tipping point where instead of being beneficial, higher temperatures are causing drought, which is now decreasing plant growth on a planetary scale. This could impact food security, biofuels, and the global carbon cycle. “This is a pretty serious warning that warmer temperatures are not going to endlessly improve plant growth,” said Steven Running from the University of Montana.

During the 1980s and 1990s global terrestrial plant productivity increased as much as six percent. Scientists say that happened because during that time, temperature, solar radiation and water availability — influenced by climate change — were favorable for growth.

During the past ten years, the decline in global plant growth is slight – just one percent. But it may signify a trend.

Interannual shifts in plant productivity (green line) fluctuated in step with shifts in atmospheric carbon dioxide (red line) between 2000 through 2009. Credit: Maosheng Zhao and Steven Running

“These results are extraordinarily significant because they show that the global net effect of climatic warming on the productivity of terrestrial vegetation need not be positive — as was documented for the 1980’s and 1990’s,” said Diane Wickland, of NASA Headquarters and manager of NASA’s Terrestrial Ecology research program.

A 2003 paper in Science led by then University of Montana scientist Ramakrishna Nemani (now at NASA Ames Research Center, Moffett Field, Calif.) showed that land plant productivity was on the rise.
Running and co-author Maosheng Zhao originally set out to update Nemani’s analysis, expecing to see similar results as global average temperatures have continued to climb. Instead, they found that the impact of regional drought overwhelmed the positive influence of a longer growing season, driving down global plant productivity between 2000 and 2009.

The discovery comes from an analysis of plant productivity data from the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite, combined with growing season climate variables including temperature, solar radiation and water. The plant and climate data are factored into an algorithm that describes constraints on plant growth at different geographical locations.

For example, growth is generally limited in high latitudes by temperature and in deserts by water. But regional limitations can vary in their degree of impact on growth throughout the growing season.

Zhao and Running’s analysis showed that since 2000, high-latitude northern hemisphere ecosystems have continued to benefit from warmer temperatures and a longer growing season. But that effect was offset by warming-associated drought that limited growth in the southern hemisphere, resulting in a net global loss of land productivity.

“This past decade’s net decline in terrestrial productivity illustrates that a complex interplay between temperature, rainfall, cloudiness, and carbon dioxide, probably in combination with other factors such as nutrients and land management, will determine future patterns and trends in productivity,” Wickland said.
The researchers plan on maintaining a record of the trends into the future. For one reason, plants act as a carbon dioxide “sink,” and shifting plant productivity is linked to shifting levels of the greenhouse gas in the atmosphere. Also, stresses on plant growth could challenge food production.

“The potential that future warming would cause additional declines does not bode well for the ability of the biosphere to support multiple societal demands for agricultural production, fiber needs, and increasingly, biofuel production,” Zhao said.

“Even if the declining trend of the past decade does not continue, managing forests and croplands for multiple benefits to include food production, biofuel harvest, and carbon storage may become exceedingly challenging in light of the possible impacts of such decadal-scale changes,” Wickland said.

The team published their findings Aug. 20 in Science.

Source: NASA

August 19, 2010December 24, 2015 by Nancy Atkinson

Astronomers Now Closer to Understanding Dark Energy

Understanding something we can’t see has been a problem that astronomers have overcome in the past. Now, a group of scientists believe a new technique will meet the challenge of helping to solve one of the biggest mysteries in cosmology today: understanding the nature of dark energy. Using the strong gravitational lensing method — where a massive galaxy cluster acts as a cosmic magnifying lens — an international team of astronomers have been able to study elusive dark energy for the first time. The team reports that when combined with existing techniques, their results significantly improve current measurements of the mass and energy content of the universe.

Using data taken by the Hubble Space Telescope as well as ground-based telescopes, the team analyzed images of 34 extremely distant galaxies situated behind Abell 1689, one of the biggest and most massive known galaxy clusters in the universe.

Through the gravitational lens of Abell 1689, the astronomers, led by Eric Jullo from JPL and Priyamvada Natarajan from Yale University, were able to detect the faint, distant background galaxies—whose light was bent and projected by the cluster’s massive gravitational pull—in a similar way that the lens of a magnifying lens distorts an object’s image.

Using this method, they were able to reduce the overall error in its equation-of-state parameter by 30 percent, when combined with other methods.

The way in which the images were distorted gave the astronomers clues as to the geometry of the space that lies between the Earth, the cluster and the distant galaxies. “The content, geometry and fate of the universe are linked, so if you can constrain two of those things, you learn something about the third,” Natarajan said.

The team was able to narrow the range of current estimates about dark energy’s effect on the universe, denoted by the value w, by 30 percent. The team combined their new technique with other methods, including using supernovae, X-ray galaxy clusters and data from the Wilkinson Microwave Anisotropy Probe (WMAP) spacecraft, to constrain the value for w.

“Dark energy is characterized by the relationship between its pressure and its density: this is known as its equation of state,” said Jullo. “Our goal was to try to quantify this relationship. It teaches us about the properties of dark energy and how it has affected the development of the Universe.”

Dark energy makes up about 72 percent of all the mass and energy in the universe and will ultimately determine its fate. The new results confirm previous findings that the nature of dark energy likely corresponds to a flat universe. In this scenario, the expansion of the universe will continue to accelerate and the universe will expand forever.

The astronomers say the real strength of this new result is that it devises a totally new way to extract information about the elusive dark energy, and it offers great promise for future applications.

According to the scientists, their method required multiple, meticulous steps to develop. They spent several years developing specialized mathematical models and precise maps of the matter — both dark and “normal” — that together constitute the Abell 1689 cluster.

The findings appear in the August 20 issue of the journal Science.

Sources: Yale University, Science Express. ESA Hubble.

August 19, 2010December 24, 2015 by Nancy Atkinson

Cosmic Volcano Erupting in M87

A new composite image of M87 features X-rays from Chandra (blue) and radio emission from the Very Large Array (red-orange). Credit: NASA/Chandra

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It’s the Eyjafjallajokull of space! Chandra and the VLA have teamed up to find an erupting galactic “super-volcano” in the massive galaxy M87. Hot gas glowing in X-ray light (shown in blue) surrounds M87, and as the gas cools, it can fall toward the galaxy’s center where it should continue to cool even faster and form new stars. But radio observations with the Very Large Array (red-orange) suggest that in M87 jets of very energetic particles produced by the black hole interrupt this process. These jets lift up the relatively cool gas near the center of the galaxy and produce shock waves in the galaxy’s atmosphere because of their supersonic speed. Scientists say this action is similar to what took place with the Eyjafjallajokull volcano in Iceland that occurred in 2010.

With Eyjafjallajokull, pockets of hot gas blasted through the surface of the lava, generating shock waves that can be seen passing through the grey smoke of the volcano. This hot gas then rises up in the atmosphere, dragging the dark ash with it. Remember the close-up movie of the volcano’s eruption — (see below)? Shock waves propagating in the smoke are followed by the rise of dark ash clouds into the atmosphere.

In the case of this cosmic volcano in M87, the energetic particles produced in the vicinity of the black hole rise through the X-ray emitting atmosphere of the cluster, lifting up the coolest gas near the center of M87 in their wake. This is similar to the hot volcanic gases that drag up the clouds of dark ash. And just like the volcano here on Earth, shock waves can be seen when the black hole pumps energetic particles into the cluster gas. The Chandra team has provided a labeled version of the image which shows the energetic particles, cool gas and shock waves.

M87 is about 50 million light years from Earth and lies at the center of the Virgo cluster, which contains thousands of galaxies.

Source: Chandra