Universe Today

February 26, 2008December 26, 2015 by Ian O'Neill

Pluto’s Moons, Nix and Hydra, may have been Adopted

The discovery images of Nix (and Hydra) obtained by the Hubble Space Telescope. Credit: NASA, ESA, H. Weaver (JHU/APL), A. Stern (SwRI)

How many moons does Pluto have? The mini-moons of Pluto, Nix and Hydra, were discovered in 2005 (but named in 2006) during an observation campaign by the Hubble Space Telescope. The discovery of these mini-moons increase the number of natural satellites orbiting Pluto to three (including larger moon Charon). But where did these satellites come from? The current accepted theory on the formation on the large moon, Charon, is much like the theory supporting the creation of Earth’s Moon. It is thought that a large impact between two Large Kuiper Belt Objects chipped Charon away from a proto-Pluto, putting the chunk of Pluto mass into orbit. Over the years, tidal forces slowed the pair and Charon was allowed to settle into its present-day orbit. Recent theory suggests that Nix and Hydra are a by product of this collision, merely shattered fragments of the huge impact. But there are problems with this idea. Could Nix and Hydra have come from somewhere other than the Pluto-Charon impact?

The small moons that orbit the Large Kuiper Belt Object (formerly classified as a planet) can be found about 48,700 kilometers and 64,800 kilometers from the surface of Pluto. The closest moon is called Nix and the farthest, Hydra. Nix has an orbital resonance of 4:1 with Charons orbit and the larger moon Hydra has a resonance of 6:1 (i.e. Nix will orbit Pluto once for every four of Charons orbits; Hydra will orbit Pluto once for every six of Charons orbits).

The reasons behind these mini-moon orbits are only just beginning to be understood, but it is known that their resonances with Charons orbit is rooted way back during the Pluto-system evolution. If we assume Hydra and Nix were formed from a massive Kuiper Belt Object collision, the easiest explanation is to assume they are whole fragments from the impact caught in the gravity of the Pluto-Charon system. However, due to the highly eccentric orbits that would have resulted from this collision, it is not possible that the two little moons could have evolved into a near-circular orbit, in near-corotational resonance with Charon.

So, could it be possible that the moons may have formed from the dust and debris resulting from the initial collision? If there was enough material produced, and if the material collided frequently, then perhaps Nix and Hydra were born from a cold disk of debris (rather than being whole pieces of rock), eventually coalescing and forming sizeable rocky moons. As there may have been a disk of debris, collisions with the orbiting Nix and Hydra would have also reduced any eccentricity in their orbits.

But there is a big problem with this theory. From impact simulations, the post-impact disk of debris surrounding Pluto would have been very compact. The disk could not have reached as far as the present-day orbits of the moons.

One more theory suggests that perhaps the moons were created in a post-impact disk, but very close to Pluto, and then through gravitational interactions with Charon, the orbits of Nix and Hydra were pulled outward, allowing them to orbit far from the Pluto-Charon post-impact disk. According to recent computer simulations, this doesn’t seem to be possible either.

To find an answer, work by Yoram Lithwick and Yanqin Wu (University of Toronto) suggest we must look beyond the Pluto-Charon system for a source of material for Nix and Hydra. From simulations, the above theories on the creation of the small moons being started by material ejected from a large collision between two Large Kuiper Belt Objects (creating Pluto and Charon) are extremely problematic. They do not correctly answer how the highly eccentric orbits Nix and Hydra would have from a collision could evolve into the near-circular ones they have today.

Lithwick and Wu go on to say that the circular, corotational resonant orbits of the two moons could be created from a Plutocentric disk of small bits of rock scooped up during Plutoâ€™s orbit around the Sun. Therefore Nix and Hydra may have been formed from the rocky debris left over from the development of the Solar System, and not from a collision event creating Charon. This may hold true for the countless other Kuiper Belt Objects in orbit in the far reaches of the Solar System, no impact is necessary for the creation of the tiny moons now thought to be their satellites.

It is hoped that the New Horizons mission (launched January 21st, 2006) to the far reaches of the Solar System will reveal some of the questions that remain unanswered in the depths of our mysterious Kuiper Belt. Hopefully we will also find out whether Nix and Hydra are children of Pluto and Charon… or whether they were adopted.

Source: arXiv

February 26, 2008December 26, 2015 by Ian O'Neill

“Foresight” Wins First Prize in Apophis Asteroid Tagging Competition

The Near Earth Asteroid (NEO) Apophis is expected to flyby the Earth in 2029. However, this flyby will be more of a “fly-very-close” as the lump of rock will miss the Earth by only a few thousand kilometers. This near-miss isn’t worrying scientists too much, but should the asteroid tumble through a 400 meter gravitational “keyhole”, there is concern that the asteroid could swing by and risk another collision in 2036. Although the odds are fairly slim, astronomers need better precision in calculating Apopis’s orbital trajectory.

How can this be done? Why not send a spaceship to shadow the asteroid on its journey? The Planetary Society has announced just that. The winning design of the Apophis Mission Design Competition will send a probe and tag Apophis to gain more details about this interplanetary vagabond, and has been awarded a healthy $25,000 to help the development of the US “Foresight” mission…

99942 Apophis (otherwise known as asteroid 2004 MN4) caused quite a stir back in 2004 when it was discovered. Lacking detailed observation at the time, the probability of the 270 meter long piece of rock hitting the Earth was around 2.7% – a large risk in astronomical terms. Now we are sure the asteroid will fly straight by, albeit rather close. It is estimated that Apophis will pass within the orbit of geostationary satellites located at 35,786 km above Earth, allowing amateur astronomers a great opportunity to observe the NEO (it will be possible to see the asteroid with the naked eye at night), whilst being secure in the knowledge that it’s not going to come any closer.

So, panic over? Not quite. Although Apophis will miss us on its first approach in 2029, we might not be so lucky on one of its return trips in 2036. During its flyby in 2029, should the asteroid pass through a critical gravitational “keyhole” measuring only 400 meters across, the gravitational deflection applied to the Apophis asteroid may adjust its orbit, setting it up for a collision course with Earth seven years later.

This is the reason for events such as the Planetary Society’s Apophis Mission Design Competition, to raise awareness of the risk posed by NEOs. Although the winning entry, designed by SpaceWorks Engineering Inc. (Atlanta, Georgia) in conjunction with SpaceDev Inc. (Poway, California), is in the design phase, it is hoped that the completed project could launch by 2012. “Foresight” is intended to fly to Apophis and tag the rock with tracking equipment. The orbiter will continue to study the asteroid and follow it on its orbit around the Sun, gathering valuable information about its composition, center of mass, surface features and, most importantly, its trajectory.

Missions plans such as Foresight are required by the international community to be used should the threat of an asteroid collision become reality (and not remain in cheesy sci-fi movies like Deep Impact or Armageddon).

“Apophis isn’t science fiction, it isn’t a blockbuster Hollywood movie; it is very real.” – Dan Geraci, the Planetary Society’s board chairman.

For more information on the winning entry and the other award winning designs, see the Planetary Society’s Apophis Mission Design Competition website.

February 26, 2008December 26, 2015 by Fraser Cain

Your Photos of the Total Lunar Eclipse

I asked and you delivered. Here is just a fraction of the eclipse photos Universe Today readers sent in. Thanks to everyone who participated!

Up first, here’s a mosaic of six images of the Moon captured by Thomas Jacobs using a 4.5″ reflector from Woodstock, Georgia in the US. The photos were captured through a pretty heavy cloud cover.

Rick Stankiewicz captured this photo of the eclipse from Thunder Bay at -24 degrees Celsius. Outside, watching the eclipse for almost 5 hours – now that’s dedication. You can see Saturn and Regulas in the image as well.

An image of the eclipse captured by John Gianforte at the University of New Hampshire observatory. They had more than 100 people on site, visiting the observatory during the eclipse. And I’m jealous to report… they had perfect weather for viewing.

Edward Willett captured this image from Regina, Saskatchewan. He says this was the best he could do under the frigid conditions, with a frozen 6-year old tugging at his arm to go back inside, but I think it’s pretty great.

And from South Africa, here’s Philip van Heerden’s photograph, taken near twilight.

Julia Tchervova

Dean and Betty Johnson

February 26, 2008December 26, 2015 by Mark Mortimer

Book Review: Final Countdown

Flying bricks shouldn’t invoke glamorous images, but NASA’s space shuttle does just that. Its bright white paint glowing over a heavy matt black base conveys the sense of majesty and strength that well belongs to this craft. Pat Duggins’ book Final Countdown â€“ NASA and the End of the Space Shuttle Program builds on this impression, even if it contains an undertone similar to an eulogy.

With NASA setting a hard deadline finalizing the flights of the space shuttle, we know the end is near. After tens of years and wild swings of fortune, this dream of ready space transportation is being laid to rest. Many reasons accompany this decision, from political shenanigans to technical tom foolery, and many other options in between. Perhaps, though, it’s just the lack of public interest that’s doomed this endeavour.

In Duggins’ book, many of the reasons for the end of the shuttle program get mentioned. As well, it covers major milestones for the program. But, it’s not a concise history nor a program review. Rather, Duggins book takes the reader on a human perspective. In it, the social issues come more to the fore than those of a technical nature. As such, he places no expectations on the reader being enamoured by the technology. But, Duggins apparently has great fondness for the space industry, admiration for the practitioners and lofty dreams of humanity’s capabilities. Thus, the book reflects Duggins appreciation of the space shuttle program, from its early inception of being an inexpensive replacement for Apollo to its present being the fundamental tool for space station construction. Though he acknowledges the shuttle’s shortcomings, he also lauds it successes.

Central to Duggins’ discussion is the dramatic influence of politics upon the space shuttle. Whether as a sword to impress foreign nations, a bribe to placate trade partners or a means toward global peace, the shuttle is shown to have had its part to play. This forms the basis of the book’s reasoning. The shuttle, upon inception, had no real purpose, so one had to be found. But, even with a purpose, constant public support was crucial. A reader’s interest in this play and counter-play of politics and public support will easily extend to an interest in this book.

However, while Duggins brings the reader along for the ride that’s been the space shuttle program, he doesn’t venture beyond. Yes, the space shuttle now has a final countdown and much discussion and effort is ongoing to regarding its successor. And, as shown, not only must the protege meet mission requirements, it must also have a mission. Nevertheless, aside from reciting some lessons learned, Duggins adds little to this. Hence, a reader looking for an enjoyable read that encompasses the space shuttle program to date will find this book warm, provoking and encompassing. Those looking for depth and deductions will be less rewarded.

Space travel has always forced harsh cold reality onto brave dreams. The space shuttle is a continuance of the dream of humankind’s aspirations to readily fly away from Earth. Pat Duggins in his book Final Countdown â€“ NASA and the End of the Space Shuttle Program shows the results of our best attempt, to date, to make ready space travel a reality. And, the end of the space shuttle program is just the beginning of another chapter of our space fairing dream.

Click here to read more reviews online, or purchase a copy from Amazon.com.

February 26, 2008December 26, 2015 by Fraser Cain

Podcast: Where is the Centre of the Universe?

There are some people â€“ Iâ€™m not naming names â€“ who think the universe revolves around them. In fact, for most of humankind, everybody thought that. Itâ€™s only been in the last few hundred years that scientists finally puzzled out that the Earth isnâ€™t the centre of the universe at all. That begs the question: where is the centre?

Click here to download the episode

Where is the Centre of the Universe? – Show notes and transcript

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

February 26, 2008December 26, 2015 by Fraser Cain

New Technique for Finding Space Diamonds

When researchers examine meteorites, they often find them sprinkled with teeny tiny diamonds – 25,000 times smaller than a grain of sand. In fact, these nanodiamonds make up 3% of the carbon found in meteorites. Astronomers think diamonds might actually be common out there in the Universe, and they’ve developed a new technique to find them.

The first hint of space diamonds came in the 1980s, when scientists studying meteorites discovered they were sprinkled with nanometer-sized diamonds. This has to be an indication of the environment of the stellar environment where the meteorites formed. There could be 10,000 trillion particles in a single gram of dust and gas.

Researchers at NASA’s Ames Research Center developed a computer simulation that simulated the conditions of the interstellar medium that would be rich in nanodiamonds. According to their simulation, clouds with these particles should be visible to NASA’s Spitzer Space Telescope.

The diamonds haven’t been seen in space because astronomers haven’t been looking in the right places. Since it takes a lot of high-energy ultraviolet light to make the diamonds shine, the researchers think Spitzer should be examining the environments around very hot, young stars, which produce large amounts of ultraviolet radiation.

Here on Earth, diamonds are formed by the intense heat and pressure of the Earth’s interior working over long periods. So how can they form in space? Instead of the heat and pressure we have on Earth, their environment is the exact opposite: diffuse clouds of cold molecular gas.

Astronomers aren’t sure, but now that they’ve got a technique to spot them with Spitzer, they’ll be studying gas clouds to understand the common conditions.

Original Source: NASA/Spitzer News Release

February 25, 2008December 26, 2015 by Ian O'Neill

Nanotechnology and “Electrochromics” Successfully Tested On Board Satellite MidSTAR-1

The zero-gravity of Earth orbit is a massive attraction to developers of new technologies. This highly controlled environment removes one of the key forces acting on experiments here on Earth, therefore allowing new techniques to be tried out. Although it can be great to get a highly sensitive experiment to test new technologies into orbit, the experiments must also be robust enough to cope with the massive forces and vibrations during a rocket launch into space.

The US Naval Academy has announced that two new technologies have succeeded in orbital experiments on board the MidSTAR-1 satellite, signifying these new high-tech methods can indeed be carried out in space, and as an added bonus, they may have revolutionary applications down here on Earth…

The US Naval Academy (USNA) satellite called MidSTAR-1 was launched from Florida’s Cape Canaveral Air Force Station on March 8th, 2007 as a part of the USNA’s Small Satellite Program (SSP). The SSP is intended to send miniature, inexpensive satellites into orbit where experiments and other operations can be carried out. The satellites and experiments are designed, constructed and controlled by officers in the US Navy.

Results from two experiments being carried out on MidSTAR-1 have just been announced, and they appear to be a resounding success. The first experiment uses nanotechnologyÂ to detect dangerous chemicalÂ compounds in the air. Almost like a miniature smoke detector, the new method is designed for use in space environments (on board missions such as the International Space Station) as well as counter-terrorism activities here on Earth. The second experiment tests the response of a radiative film (no thicker than a plastic freezer bag) that could be used to regulate the temperature of spacecraft. Both technologies have never been tested in space and both appear to have functioned rather well.

In the nanotechnology experiment,Â the Nano Chemsensor Unit (NCSU) uses very thin nano-tube material (10,000 times thinner than a human hair) to detect poisonous gases in a space-borne environment, primarily protecting astronauts. In fact, this new detector is only the size of a pencil eraser, but has many times the sensitivity of a household smoke detector. The NCSU performed excellently, detecting the target contaminants repeatedly. It is hoped that tiny detectors such as this will be installed in future NASA missions to detect fuel leaks or contamination by common air pollutants such as nitrogen dioxide. Exposure to the vacuum of space, radiation and vibrations at launch do not seem to significantly affect the prototype sensor. Terrestrial applications of the system include atmospheric monitoring and even explosive residueÂ detection during homeland security exercises.

The second technology to be successfully tested is a thin film that changes its characteristics depending on the amount of electric current that is passed across it. This revolutionary material could be used to “wrap” spaceships so their temperature can be regulated. The film can radiate waste heat away from the body of the spacecraft, or can insulate it, holding the heat inside. The science behind this material is known as electrochromics, and before this mission it had never been tested in space. The material is very lightweight, efficient and uses very little energy, a superb addition to any spaceflight mission. Terrestrial applications of this material include using an electrochromic film to coat buildings, making them energy efficient during the winter, but keeping homes cool during summer. This should reduce the amount of energy required to heat and cool buildings, cutting down on cost and the production of greenhouse gases.

Another exciting use of this film could be to use it to surround future robots exploring the solar system, optimizing the temperature for best performance. Also, this technology would be vital to the energy conservation on future manned Moon and Mars bases.

Whatever the application, these preliminary experiments are proving to be highly successful and may revolutionize some aspects of space- and terrestrial-based technology.

“MidSTAR is the seventh piece of hardware that the small satellite program has flown. It’s by far the most sophisticated and most ambitious. It’s proven to be the most productive and all four experiments operating in space are producing excellent data.” – Billy Smith, Director of the Small Satellite Program.

Source: Science Daily

February 25, 2008December 26, 2015 by Nancy Atkinson

New ESA Rover Will Look For Life On Mars

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NASA’s Mars Exploration Rovers (MER) have been an outstanding success in their longevity and helping us to understand the role of water in Mars’ past. But Spirit and Opportunity don’t have the instruments on board to answer the question foremost in many people’s minds: Is there, or was there ever life on Mars?

A new spacecraft being readied by the European Space Agency (ESA) will have that ability. The rover for the ExoMars 2013 mission will have an on-board subsurface radar, a drill, and life-detection equipment as part of the scientific payload.

To help prepare for the mission, scientists at Aberystwyth University in Wales have simulated the surface of Mars in their lab to test the “roving” capabilities of the vehicle. Also being tested are the robotic arm for collecting samples and a panoramic camera.

The ExoMars mission will also have an orbiter that will scan for the best landing site for the rover. The rover is slated to travel to ten different locations in 6 months. The rover will use a radar system that can scan the surface and subsurface, a drill that can dig down 1-2 meters below the surface and gather a sample that will be brought to the onboard instruments that will look for life, past or present, in the Mars landscape.

A robotic arm that is part of this system is similar to arm that was part of the ill-fated Beagle 2 lander, that crashed on Mars surface in 2003. But the new arm has been improved, and it is hoped the arm will work with on-board cameras and to be able to acquire rock samples autonomously.

The rover will weigh about 140-180 kg, comparable to the NASA’s MER. The main scientific objectives of the ExoMars mission are to study the biological environment of Mars surface, to characterize the Mars geochemistry and water distribution and to identify possible surface hazards to future human missions.

The mission is scheduled to launch in 2013 and land on Mars in 2014.

Original News Source: BBC

February 25, 2008December 26, 2015 by Nancy Atkinson

Be A Carbon Hero

NASA is quite proud of its spinoffs technology developed for the space agency’s needs in space that in turn contribute to commercial innovations that improve life here on Earth. And rightly so. Just as a quick example, improvements in spacesuits have led to better protection for firefighters, scuba divers and people working in cold weather. But the list of NASA spinoffs is quite extensive.

Just like NASA, the European Space Agency (ESA) has a Technology Transfer office to help inventors and businesses use space technology for non-space applications. The latest invention touted as an ESA spinoff is a small hand-held device called a Carbon Hero that might help make people more aware of the carbon footprint they are leaving behind due to vehicle emissions.

Used in conjunction with a cell phone, the Carbon Hero receives data from navigation satellites to determine the mode of transportation being used. The device’s algorithm is able to use the speed and position of the user to determine how they are traveling, and how much CO2 they are generating. The user doesn’t have to enter any information, the data is computed automatically.

The user would get feedback on the environmental impact of different types of transportation – whether by train, plane, bike or by foot. The Carbon Hero lets the user compare one kind of travel with another and calculate the environmental benefits daily, weekly and monthly.

“If you go on a diet you want to see if all that effort has made a difference so you weigh yourself. The beauty of our system is that it’s easy; you have a “weighing scale” on you all the time giving you your carbon footprint. When you make the effort to walk instead of taking the car you can immediately see the result, so it feels more worthwhile doing it and you are more likely to stick with it,” says Andreas Zachariah, a graduate student from the Royal College of Art in London and inventor of Carbon Hero.

The device has been tested using the GPS system, but will be fully operational after Galileo, the European global navigation system is fully up and running.

Learn more about ESA’s Technology Transfer Programme Office.

Learn more about NASA Spinoffs.

Original News Source: ESA Press Release

February 25, 2008December 26, 2015 by Tammy Plotner

Mercury and Venus Team Up on Tuesday

If you have an open horizon to the east on Tuesday, February 26, you’ll have the opportunity to spot Mercury and Venus together. Both inner planets will team up in their closest approach and appear to be about a degree apart in the pre-dawn sky. For those with a telescope, this will be an excellent time to catch both planets in different phases at the same time in the eyepiece!

For many of us, the chances to spot the swift inner planet – Mercury – are few and far between. While Mercury traditionally gets about as bright as the stars in the Big Dipper, it’s proximity to the Sun makes it hard to see either right after sunset or just before the dawn. Low clouds on the horizon, sky light, obstructing trees or buildings… many things combine to make Mercury notoriously difficult to observe. However, when a bright star – or in this case, a planet – is nearby, the task becomes a whole lot easier!

On the universal date of February 26, Mercury will appear low on the east/southeast horizon, precisely one hour before the Sun. Following it exactly two minutes later is brilliant Venus. Because of low position, chances are you’ll need binoculars to spot Mercury, but once your eyes have become accustomed, you may wish to try it unaided. The real treat will be to try and observe the pair telescopically. While it might seem dangerous since you’ll probably have to wait until the Sun is beginning to rise to catch them, don’t be afraid… It is perfectly safe to view them both during dawn.

Just like the phases of the Moon, both Mercury and Venus go through phases due to the relative position from which we view them. Take a look at the solar system as seen from above and you can easily understand why you see them as you do! Mercury will appear like the first quarter Moon, while Venus will be very gibbous. If you have filters, using them will help diminish the glare and make seeing the phases easier. If you do not. you can either wear a pair of sunglasses while at the eyepiece or wait until the skies begin to brighten. If the skies are cloudy, don’t worry. The pair will be visible for several mornings yet, but will begin to separate. Your observing job is to report which direction! Does Venus drop below Mercury or rise above?

Have fun!

Here are some fun facts about Mercury.