Universe Today

October 4, 2011April 26, 2016 by Ray Sanders

World Space Week ( Oct 4th – 10th ) — Join the Fun!

World Space Week - October 4th - 10th, 2011. Image Credit: World Space Week Association

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What is World Space Week?

Founded in 1981, World Space Week Association is one of the world’s oldest space education organizations. As a partner of the United Nations in the global coordination of World Space Week, WSWA recruits and supports a worldwide network of coordinators and participants. WSWA is a non-government, nonprofit, international organization, based in the United States.

World Space Week is an international celebration of science and technology, and how each benefits the human condition. In 1999 The United Nations General Assembly declared that World Space Week will be held each year from October 4-10, commemorating two notable space-related events:

The annual kick-off date of October 4th corresponds with the October 4th 1957 launch of the first human-made Earth satellite, Sputnik 1.

The end date of October 10th corresponds with the October 10th 1967 signing of the Treaty on Principles Governing the Activites of States in the Exploration and Peaceful Uses of Outer Space, including the Moon and Other Celestial Bodies.

Here’s some information from their F.A.Q on how you can participate in World Space Week, either by volunteering or by attending an event.

Where and how is World Space Week celebrated?

World Space Week is open to everyone – government agencies, industry, non-profit organizations, teachers, or even individuals can organize events to celebrate space. WSW is coordinated by the United Nations with the support of WSWA and local coordinators in many countries.

What are the benefits of World Space Week?

WSW educates people around the world about the benefits they receive from space and encourages greater use of space for sustainable economic development. WSW also demonstrates public support for space programs and excites children about learning and their future.
Some of the other benefits include promoting institutions around the world that are involved in space and fostering a sense of international cooperation in space outreach and education.

How can schools participate?

This event is ideal for teachers to promote student interest in science and math. To encourage participation, World Space Week Association gives various educational awards each year.

Sign at NASA's Johnson Space Center announcing World Space Week. Photo Credit: NASA/WSWA

What can I do for World Space Week?

If you’d like to become involved with WSW you can:

Volunteer for World Space Week Association

Organize an event directly

Help expand and coordinate World Space Week

Encourage teachers and students to do space-related activities

Become a Volunteer

Hold an Event During World Space Week

If you hold an event, be sure to add your event to the World Space Week calendar and tell the media and your regional WSW coordinator about your planned event. You can also order World Space Week posters and display them in your community.

If you’d like to find a World Space Week event in your area, visit:http://www.worldspaceweek.org/calendar_2011.php

You can learn more about World Space Week at: http://www.worldspaceweek.org

Source: World Space Week Association

October 4, 2011December 24, 2015 by Ray Sanders

Martian Atmosphere Supersaturated with Water?

Artist's impression of the Mars Express spacecraft in orbit. Image Credit: ESA/Medialab

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Last week, scientists announced findings based on data from the SPICAM spectrometer onboard ESA’s Mars Express spacecraft. The findings reported in Science by Maltagliati et al (2011), reveal that the Martian atmosphere is supersaturated with water vapor. According to the research team, the discovery provides new information which will help scientists better understand the water cycle and atmospheric history of Mars.

What processes are at work to allow large amounts of water vapor in the Martian atmosphere?

The animated sequence to the left shows the water cycle of the Martian atmosphere in action:

When the polar caps of Mars (which contain frozen Water and CO₂) are warmed by the Sun during spring and summer, the water sublimates and is released into the atmosphere.

Atmospheric winds transport the water vapor molecules to higher altitudes. When the water molecules combine with dust molecules, clouds are formed. If there isn’t much dust in the atmosphere, the rate of condensation is reduced, which leaves water vapor in the atmosphere, creating a supersaturated state.

Water vapor may also be transported by wind to the southern hemisphere or may be carried high in the atmosphere.In the upper atmosphere the water vapor can be affected by photodissociation in which solar radiation (white arrows) splits the water molecules into hydrogen and oxygen atoms, which then escape into space.

Scientists had generally assumed that supersaturation cannot exist in the cold Martian atmosphere, believing that any water vapor in excess of saturation instantly froze. Data from SPICAM revealed that supersaturation takes place at altitudes of up to 50 km above the surface when Mars is at its farthest point from the Sun.

Based on the SPICAM data, scientists have learned that there is more water vapor in the Martian atmosphere than previously believed. While the amount of water in Mars’ atmosphere is about 10,000 times less water vapor than that of Earth, previous models have underestimated the amount of water in the Martian atmosphere at altitudes of 20-50km, as the data suggests 10 to 100 times more water than expected at said altitudes.

“The vertical distribution of water vapour is a key factor in the study of Mars’ hydrological cycle, and the old paradigm that it is mainly controlled by saturation physics now needs to be revised,” said Luca Maltagliati, one of the authors of the paper. “Our finding has major implications for understanding the planet’s global climate and the transport of water from one hemisphere to the other.”

“The data suggest that much more water vapour is being carried high enough in the atmosphere to be affected by photodissociation,” added Franck Montmessin, Principal Investigator for SPICAM and co-author of the paper.

“Solar radiation can split the water molecules into oxygen and hydrogen atoms, which can then escape into space. This has implications for the rate at which water has been lost from the planet and for the long-term evolution of the Martian surface and atmosphere.”

However, water vapour is a very dynamic trace gas, and one of the most seasonally variable atmospheric constituents on Mars.

Source: ESA/Mars Express Mission Updates

October 4, 2011December 24, 2015 by Tammy Plotner

Holmberg II – Forever Blowing Bubbles

Hubble’s famous images of galaxies typically show elegant spirals or soft-edged ellipses. But these neat forms are only representative of large galaxies. Smaller galaxies like the dwarf irregular galaxy Holmberg II come in many shapes and types that are harder to classify. This galaxy’s indistinct shape is punctuated by huge glowing bubbles of gas, captured in this image from the NASA/ESA Hubble Space Telescope.

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“I’m forever blowing bubbles… Pretty bubbles in the air…” Its name is Holmberg II, and it’s a dwarf galaxy that’s only 9.8 million light-years away. It’s part of the M81 Galaxy Group and one of the few that isn’t distracted by gravity from nearby peers. Holmberg II is an active little galaxy and one that’s full of holes – the largest of which spans 5500 light years wide. But what makes this one really fascinating is that it’s expelling huge bubbles of gas…

Here the remnants of mature and dying stars have left thick waves of dust and gas, carved into shape by stellar winds. Some ended their lives as supernovae – sending rippling shockwaves through the thinner material to hang in space like fantasy ribbons. With no dense nucleus to deform it like an elliptical galaxy, nor distorting arms like a spiral, this irregular star-forming factory is the perfect place for astronomers to take a close look stellar formation in a new way.

Keep thinking bubbles, because Holmberg II is the perfect example of the “champagne” model of starbirth – where new stars create even newer ones. How does it work? When a bubble is created by stellar winds, it moves outwards until it reaches the edge of the molecular cloud that spawned it. At the exterior edge, dust and gas have been compressed and form a nodule similar to a blister. Here another new star forms.. and triggers again… and triggers again… similar to the chain reaction which happens when you open a bottle of champagne.

And fill the glass again, because Holmberg II is also known as Arp 268. While Halton Arp certainly knows his stuff when it comes to unusual galaxies, there’s even more. According to the Hubble team, our little dwarf also has an ultraluminous X-ray source in the middle of three gas bubbles which appears in the image’s upper right hand corner. No one is quite sure of what it just might be! Maybe black hole bubbles?

“They fly so high… Nearly reach the sky. Then in my dreams they fade and die…” Perhaps Dean Martin?

Original Story Source: Hubble News.

October 4, 2011January 14, 2016 by Nancy Atkinson

Astronomy Cast Ep. 233: Radar

Radar is one of the those technologies that changed everything: it allows boats and aircraft to “see” at night and through thick fog. But it also changed astronomy and ground imaging, tracking asteroids with great accuracy, allowing spacecraft to peer through Venus’ thick clouds and revealing secrets beneath the Earth’s shifting sands.

Click here to download the episode.

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

“Radar” on the Astronomy Cast website.

October 4, 2011December 29, 2015 by Nancy Atkinson

Carnival of Space #217

This week’s Carnival of Space is hosted by our very own Ray Sanders at his very own Dear Astronomer website

Click here to read the Carnival of Space #217

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, sign up to be a host. Send and email to the above address.

October 4, 2011April 8, 2018 by Gemma Lavender

Puzzling Comet Composition Solved?

How Are Comets Formed? — The Deep Impact spacecraft successfully flew past Comet Hartley 2 in November 2010 and is an example of the type of comet that the UCLA scientists describe in their research. Image: UPI/NASA/JPL-Caltech/UMD.

For years comets have mystified scientists with their compositions that appear to have formed in both warm and cold environments, rather than in one location of a uniform temperature. But new research shows that the reason some comets feature patches of differing surface composition is not because they are made from material that formed in different parts of the Solar System, but because some parts of their surface absorb heat at varying rates. This leads to localized heat sinks and cold traps, according to a new model constructed by David Jewitt and Aurelie Guilbert-Lepoutre from the University of California, Los Angeles (UCLA). Their model shows that the chemical composition of a comet can evolve in the ten million year period during which a comet is classed as a Centaur, migrating from the Kuiper Belt to the inner Solar System.

“The Centaurs are objects which have escaped from the Kuiper belt and are drifting amongst the giant planets,” says Jewitt. “Their lifetimes in these orbits are limited to about 10 million years because they are gravitationally perturbed by the planets to other orbits. At least half are ejected from the Solar System to the interstellar medium. Some are kicked inside the orbit of Jupiter, where the ice begins to sublimate and we call them comets.”

The key is variances in the surface – thermal conductivity, reflectivity (albedo), obliquity (tilt) and even topography such as craters or hilly terrain. This leads to the creation of ‘thermal shadows’.

“Just as it is cooler in the shadow of a building than standing in the full Sun, the region beneath a bright spot or a boulder on the surface of a comet will remain cooler than the surroundings,” says Jewitt. The higher the albedo, the more sunlight is reflected away, keeping that particular patch of the comet 20 to 30 degrees Celsius cooler than its surroundings. The thermal shadows can be maintained “We have calculated the way the cool spot extends down into the interior of the comet, and examined how deep and how long-lived this cool shadow region can be for objects moving on a variety of different orbits.”

Being colder, the thermal shadows attract volatile materials such as water-ice and carbon dioxide from elsewhere on the comet, enhancing the composition there. Consequently the composition of the comet becomes strongly non-uniform, as does the activity on the comet, manifest in jets of the kind seen, for example, by the Deep impact spacecraft on the Comet Hartley 2 in November 2010.

The paper can be found on the astro-ph archive and can be read here.

October 4, 2011December 24, 2015 by Jason Major

Were Martian Rocks Weathered by Water?

Pitted rocks imaged by Opportunity. NASA/JPL-Caltech/Stu Atkinson.

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There are many ways rocks can be textured. Wind erosion, water erosion, the escape of volcanic gases during their formation (in the case of igneous rocks)… all these forces can create the pitted textures found on many rocks on Earth… and perhaps even on Mars. And according to a report published by a group of planetary geologists led by James Head of Rhode Island’s Brown University, another method may also be at play on Mars: melting snow.

Here on Earth in the hyper-arid dry valleys of Antarctica, water from melting snow erodes the surfaces of dark boulders, creating pitted textures similar to what has been found at many locations on Mars.

In order for that process to be truly analogous, though, a few conditions would have to be met on the red planet. First, the atmospheric pressure must be high enough to allow water to remain – if only temporarily – in a liquid state. Water that instantly boils away won’t have enough time to chemically attack the rock. Second, the rock itself must be at least warm enough to not freeze the water (again, must be liquid.) And third, there must actually be water, snow or frost present.

While one or more of these factors may be currently present in locations on Mars, they have not yet been found to exist all together in the same place. But that’s just what’s been found now… in Mars’ geologic past these may all have very well existed either in isolated locations or perhaps even planet-wide.

The paper’s abstract states:

For example, increases in atmospheric water vapor content (due, for example, to the loss of the south perennial polar CO₂ cap) could favor the deposition of snow, which if collected on rocks heated to above the melting temperature during favorable conditions (e.g., perihelion), could cause melting and the type of locally enhanced chemical weathering that can cause pits.

In other words, if the dry ice at Mars’ south pole had melted at one point, freed-up water vapor could have fallen on rocks elsewhere as snow. If Mars were at a point in its orbit closest to the Sun and therefore experiencing warmer temperatures the snow could have then melted – especially upon darker rock surfaces.

Still, it’s possible – or even probable – that the weathering did not occur at a consistent rate across the entire surface of the rocks. Some sides may have weathered faster or slower than others, depending on how they were exposed to the elements. But if there’s one thing Mars has had a surplus of, it’s time. Even if the processes outlined in the report are indeed the cause of Mars’ pitted rocks, they have likely been in play over many hundreds of millions – even billions – of years.

Read the team’s report on the Journal of Geophysical Research here.

Thanks to Stu Atkinson for his color work on the images from Opportunity. Check out his blog The Road to Endeavour for updates on the rover’s progress.

October 4, 2011December 24, 2015 by Nancy Atkinson

Accelerating Expansion of Universe Discovery Wins 2011 Nobel Prize in Physics

The accelerating, expanding Universe. Credit: NASA/WMAP

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Three scientists shared the 2011 Nobel Prize for physics for the discovery that the expansion of the universe is speeding up, the Nobel prize committee announced today. Half of the $1.5 million prize went to American Saul Perlmutter and the rest to two members of a second team which conducted similar work: American Adam Riess and U.S.-born Brian Schmidt, who is based in Australia. All three made the discovery through observations of distant supernovae.

Perlmutter is from the Lawrence Berkeley National Laboratory and University of California, Berkeley, and worked on the Supernova Cosmology Project. Schmidt is from the Australian National University and Riess is from the Johns Hopkins University and Space Telescope Science Institute, Baltimore. They worked together on the High-z Supernova Search Team.

In response to the announcement, Professor Sir Peter Knight, President of the Institute of Physics, said, “The recipients of today’s award are at the frontier of modern astrophysics and have triggered an enormous amount of research on dark energy.

“These researchers have opened our eyes to the true nature of our Universe. They are very well-deserved recipients.”

Source: IOP

October 3, 2011December 24, 2015 by Jon Voisey

High Precision Study of Exoplanet WASP 10b

SuperWasp Cameras. Credit: SuperWASP project & David Anderson

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Originally discovered by the Wide Angle Search for exoPlanets (WASP) survey in 2008, the eclipsing exoplanet WASP 10b has been reluctant to allow its properties to be pinned down. While its mass has been pinned down by two independent groups to right around 3 times the mass of Jupiter, the radius and thus, the overall density which gives hints at the composition, has been harder to determine. Groups have also reported oddities in the timing of the eclipses that may hint at the presence of another planets whose gravitational tug is changing the orbit of 10b. A new study attempts to answer these questions with high precision observations from the Spanish 2.2 meter Calar Alto Observatory.

The new study, led by astronomers from Nicolaus Copernicus University in Poland, is the first of WASP 10b to take into account the effects of star spots. Since the host star is a K-dwarf such spots should be common. When such spots are present, the planet can eclipse them as well, making the overall brightness increase temporarily. This apparent change in the brightness of the star makes small changes in how astronomers would determine the overall brightness of the star. This brightness is used to determine the properties of the star, such as its radius, which also factor into determining the radius of the planet. As such, these spots should be taken into account for the most accurate understanding possible.

The team observed four transits of the planet in late 2010. In that time, star spots were present for three of the four transits. With the spots subtracted out, the team agreed with previous estimates of mass, but found an even lower value for the radius than either of the previous studies. Their value was only a few percent wider than Jupiter despite being three times as massive. While this doesn’t make WASP 10b most dense planet known, it does rank among the top contenders.

These results have implications for how planets may form in general. Since WASP 10 is estimated to be a relatively young star, it would imply that the major planet formed a rocky core early on and that it wasn’t deposited later through collisions. The team estimates that it would require a total mass for the core of roughly 300-400 times the mass of Earth.

When the team added their new data to previous studies of the system, they found that the timing of the transits have continued to change and these changes could not be the product of other effects, such as star spots on the limb of the star altering the shape of the light curve. As such, they note that “this finding supports a scenario in which the second planet perturbs the orbital motion of WASP 10b.”

October 3, 2011January 24, 2021 by VirtualAstro

The Draconid Meteor Shower – A Storm is Coming!

Geminid Meteor - George Varros (courtesy NASA)

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The Draconids are coming! Will this meteor shower produce a storm of observable meteors, or just a minor squall? The Draconid Meteor Show should begin on October 8, 2011 starting at dusk (roughly 19:00 BST) and continue through the evening. Peak activity of this normally minor and quiet shower is estimated to be at 21:00 BST (20:00 UT). There seems to be a wide range of predictions for this year’s shower, but some astronomers believe there could be up to 1,000 meteors per hour, making this a meteor storm!

The Draconids or Giacobinids as they are also known, radiate from a point in the constellation of Draco the Dragon in the Northern hemisphere. In the past, notably in 1933 and 1946, the Draconids turned into a meteor storm with meteor rates of more than one every second!

So, will this year bring us a storm? Astronomers believe so as the predicted path of the Earth through the debris streams of comet 21P/Giacobini-Ziner is favorable for a major storm, similar to what has been seen in previous years. Some reports say NASA is even considering the potential risk of damage to the International Space Station and other satellites due to meteroid impacts.

Some astronomers, on the other hand, are saying this shower could be a dud, with only 5 or so meteors per hour.

Observers in the UK and Northern Europe are ideally placed to see the peak of the Draconids. Unfortunately the peak occurs in the day time for North America. There will also be a bright Moon which may drown out many but the brightest meteors, but if predictions are correct, you will still see many. You may see Draconid meteors on the 7th an the 9th also, so it is worth going out and checking the skies.

The Constellation Draco in the northern sky in the northern hemisphere.

Draco is a circumpolar constellation visible all night from northern latitudes.

There is no skill or even astronomical knowledge needed to enjoy meteor showers. All you need is to be comfortable, away from bright lights and your eyes. Sit back on a recliner or garden chair and fill your gaze with sky as meteors can appear anywhere as they radiate from the constellation of Draco. For more info on how to enjoy meteor showers visit meteorwatch.org

So what will you see? Draconid meteors are usually slow and bright streaks of light, but if you look away, you can still miss them so keep your gaze on the sky.

There are no guarantees of a meteor storm or even a good meteor shower as these phenomena can be very unpredictable, but the only way to find out is to go outside and look up.

If predictions are correct, you could be in for a spectacular treat and something truly memorable, so don’t miss it. Even if it is cloudy, you can listen to the meteor shower or you can watch as they enter Earths atmosphere

For more information on the Draconids, see the International Meteor Organization’s post on this year’s shower.

Good Luck!